WO2003103194A1 - Bidirectional optical transmission system and optical transmission/reception device - Google Patents

Bidirectional optical transmission system and optical transmission/reception device Download PDF

Info

Publication number
WO2003103194A1
WO2003103194A1 PCT/JP2003/006530 JP0306530W WO03103194A1 WO 2003103194 A1 WO2003103194 A1 WO 2003103194A1 JP 0306530 W JP0306530 W JP 0306530W WO 03103194 A1 WO03103194 A1 WO 03103194A1
Authority
WO
WIPO (PCT)
Prior art keywords
optical
signal
circuit
downstream
optical fiber
Prior art date
Application number
PCT/JP2003/006530
Other languages
French (fr)
Japanese (ja)
Inventor
加藤 和利
山林 由明
昇 石原
俊一 東野
由一 千葉
鈴木 安弘
Original Assignee
エヌティティエレクトロニクス株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by エヌティティエレクトロニクス株式会社 filed Critical エヌティティエレクトロニクス株式会社
Priority to AU2003241767A priority Critical patent/AU2003241767A1/en
Priority to JP2004510151A priority patent/JP4369363B2/en
Publication of WO2003103194A1 publication Critical patent/WO2003103194A1/en

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04JMULTIPLEX COMMUNICATION
    • H04J14/00Optical multiplex systems
    • H04J14/02Wavelength-division multiplex systems
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B10/00Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/25Arrangements specific to fibre transmission
    • H04B10/2587Arrangements specific to fibre transmission using a single light source for multiple stations

Definitions

  • the present invention relates to a bidirectional optical transmission system for bidirectionally transmitting an optical fiber between a master device and a slave device, and an optical transceiver.
  • Figure 16 shows the configuration of a conventional bidirectional optical transmission system.
  • 15-1 and 15-2 are optical fibers
  • 41 is an optical transmission circuit of a main unit
  • 42 is an optical receiving circuit of a main unit
  • 43 is an optical receiving unit
  • 44 is an optical transmission unit.
  • Reference numeral 48 denotes an optical receiving circuit of the slave device
  • 49 denotes an optical transmitting circuit of the slave device.
  • FIG. 16 shows a bidirectional optical transmission system in which bidirectional transmission is performed between a master device and a slave device using a two-core optical fiber. That is, as shown in FIG. 16 (a), between the optical transmission circuit 41 of the main device and the optical reception circuit 48 of the slave device, and between the optical transmission circuit 49 of the slave device and the optical reception circuit of the master device. 4 and 2 are connected by two-core optical fibers 15 _ 1 and 15 _ 2 to perform bidirectional transmission.
  • the optical transmission circuit 41 of the main unit transmits a downstream optical signal through the optical fiber 15-1
  • the optical reception circuit 48 of the slave unit receives the downstream optical signal.
  • the optical transmission circuit 49 of the slave device transmits an upstream optical signal through the optical fiber 15-2, and the optical reception circuit 42 of the master device receives the upstream optical signal.
  • FIG. 16 (b) shows a head-end configuration of the optical receiving circuit 48 and the optical transmitting circuit 49 of the slave device.
  • the downstream optical signal received via the optical fiber 15-1 is detected by the optical receiver 43, and the detected downstream signal is transmitted to the optical receiver 43.
  • the signal is processed in the receiving circuit 48.
  • the upstream signal is modulated into an upstream optical signal by the optical transmitter 44.
  • the modulated upstream optical signal is transmitted through the optical finos I5-2.
  • FIG. 17 The operation of transmitting and receiving an upstream optical signal or downstream optical signal is shown in FIG.
  • the light-emitting element is driven by the drive current of the downstream signal in the optical transmission circuit of the main device (FIG. 17 (a)).
  • the light output of the light-emitting element is almost linearly related to the drive current (Fig. 17 (b)).
  • the optical transmission circuit of the main unit transmits the downstream optical signal output close to the waveform of the downstream signal (Fig. 17 (c)).
  • a threshold is set for the signal component input to the optical receiver circuit, and a downstream signal is detected (Fig. 17 (d)).
  • the optical transmission circuit of the slave device and the operation of the optical reception circuit of the master device That is, the optical transmission circuit of the master device and the optical transmission circuit of the slave device must each have a light emitting element.
  • Fig. 18 shows the configuration of another conventional bidirectional transmission system.
  • This configuration is a bidirectional optical transmission system in which a two-core optical fiber bidirectional / wavelength-division multiplexed multipoint transmission is performed between a main device and a plurality of slave devices.
  • 4 1 — 1 to 4 1 — N is the optical transmission circuit of the main unit
  • 4 2 — 1 to 4 2 — N is the optical receiving circuit of the main unit
  • 4 5 — 1 and 4 5 _ 2 are the main unit.
  • 15-1 and 15-2 are optical fibers
  • 16-1 and 16-2 are wavelength multiplex circuits provided in the middle of the optical fiber
  • 48-8 :! ⁇ 48 — N is the optical receiving circuit of the slave
  • 49 1:! 449-N is the optical transmission circuit of the slave device.
  • the symbol N is used to represent two or more.
  • optical transmission circuit 4 1 1; 44 1 —N represents two or more optical transmission circuits.
  • a plurality of optical transmission circuits 4 1-1 to 4 1 1 N of the main unit transmit wavelengths (A 1 ⁇ 2 ,...) Assigned to respective downstream optical signals modulated by the downstream signals.
  • the signal is transmitted to the wavelength multiplexing circuit 45-1 of the main device.
  • the wavelength division multiplexing circuit 45-1 multiplexes downstream optical signals of different wavelengths transmitted from a plurality of optical transmission circuits onto the optical fiber 115-1.
  • the wavelength multiplexing circuit 16-1 provided in the middle of the optical fiber 15-1 separates each downstream optical signal toward each slave device according to the wavelength.
  • Optical receiving circuit of each slave device 4 8 — 1 to 4 8 — N detect signal components from the downstream optical signal received through the optical fiber 15-1.
  • the optical transmission circuits 49-1 to 49-1 N of the respective slave devices transmit the upstream optical signals modulated by the upstream signals to the optical fibers 15-2.
  • a wavelength multiplexing circuit 16-2 provided in the middle of the optical fiber 15-2 is a plurality of optical transmitting circuits 49-:! ⁇ 49-N, each of which has a wavelength (A i, ⁇ 2 , ... ⁇ )) are wavelength-multiplexed toward the main unit.
  • the wavelength multiplexing circuit 45-2 of the master device is a pre-assigned wavelength ( ⁇ ; ⁇ ⁇ 2 , ⁇ ⁇ ⁇ ⁇ ) transmitted from the optical transmission circuits 49-1 to 49- ⁇ of the slave devices. ) Is wavelength-separated for each wavelength toward the optical receiver circuit 42-1 to 42_ ⁇ of the main device.
  • Each of the plurality of optical receiving circuits 42-1 to 42- ⁇ of the main device detects an upstream signal from the received upstream optical signal.
  • each of the optical transmission circuits 49_1 to 49_ ⁇ of the slave device must transmit an upstream optical signal of a predetermined wavelength.
  • Optical transmission circuit of each slave device 49 1 ⁇ 49_ ⁇ must each have a light emitting element, and furthermore, it is necessary to control or maintain the wavelength of these light emitting elements with high precision. Slave devices are generally distributed at different locations, and therefore have different environmental temperatures. When the wavelength of the light-emitting element shifts from a predetermined value due to a change in environmental temperature, light loss occurs in the wavelength multiplexing circuit 16-2 in the optical fiber 15-2 and the wavelength multiplexing circuit 45-2 in the main unit. Increase. Furthermore, if the transition is large, transmission may not be possible.
  • the present invention eliminates the need for a light emitting element in the optical transmission circuit of the slave device, and controls or maintains the wavelength of the light emitting element with high accuracy in the optical transmission circuit of the slave device.
  • the purpose is to make it unnecessary.
  • semiconductor optical amplifier circuits eg, T. Mukai and T. Saitoh, “5.2 dB noise figure in a 1.5 ⁇ m InGaAsP traveling wave laser amplifier”, Electron. t., Vol.23, No.5, pp.216-218 (1987)).
  • This is a semiconductor optical amplifier circuit in which the waveforms of the input optical signal and the output optical signal have a linear relationship. Disclosure of the invention
  • the first invention of the present application is a bidirectional optical transmission system in which a two-core optical fiber is bidirectionally transmitted between a master device and a slave device using a first optical fiber and a second optical fiber.
  • An optical transmission circuit for transmitting, to the first optical fiber, a downstream optical signal in which a bias component is superimposed on a signal component modulated by a downstream signal, and the second optical fiber;
  • An optical receiving circuit for detecting an upstream signal from an upstream optical signal received through the optical fiber, wherein the slave device detects the signal component from the downstream optical signal received through the first optical fiber;
  • An optical transmission circuit for transmitting the upstream optical signal, which is obtained by modulating a part of the received downstream optical signal with the upstream signal by a saturation amplification / attenuation circuit, to the second optical fiber, Two-way light transmission Square Mel by formula.
  • the second invention of the present application is a bidirectional optical transmission system for performing directional multiplex bidirectional transmission between a master device and a slave device using a single-core optical fiber, wherein the master device converts a signal component modulated by a downstream signal into a signal component.
  • An optical transmission circuit for transmitting a downstream optical signal having a bias component superimposed thereon toward the optical fiber; and an optical receiving circuit for detecting an upstream signal from an upstream optical signal received through the optical fiber.
  • An optical receiving circuit for detecting the signal component from the downstream optical signal received through the optical fiber; and an upstream optical signal obtained by modulating a part of the received downstream optical signal with the upstream signal by a saturation amplification / attenuation circuit.
  • a light transmission circuit for transmitting the light toward the optical fiber.
  • the third invention of the present application is a two-way optical transmission system in which the main device and the slave device are two-way multiplexed bidirectionally transmitted by a single optical fiber between the master device and the slave device.
  • the saturation amplification / attenuation circuit is a semiconductor optical amplifier, and a film having a higher reflectivity than a cleavage state is coated on an end surface facing the incident end surface of the down optical signal.
  • the fourth invention of the present application which is a bidirectional optical transmission system characterized by a reflection type configuration in which a signal is transmitted from an incident end face of a signal, comprises a first optical fiber between a master device and a plurality of slave devices.
  • Each of the slave units includes: an optical receiving circuit that detects the signal component from the downstream optical signal received through the first optical fiber; and a saturation amplification / attenuation unit that partially amplifies the received downstream optical signal.
  • An optical transmission circuit for transmitting the upstream optical signal modulated by the upstream signal to the second optical fiber by a circuit.
  • a fifth invention of the present application is a bidirectional optical transmission system in which a main device and a plurality of slave devices are transmitted in a single-core optical fiber in a multiplexed bidirectional / wavelength multiplexed multipoint manner, wherein the main device is a downstream signal.
  • a plurality of optical transmission circuits for transmitting, to the optical fiber, respective downstream optical signals in which a bias component is superimposed on a modulated signal component; and an upstream signal from each upstream optical signal received through the optical fiber.
  • a plurality of optical receiving circuits for detecting, the plurality of slave devices each comprising: an optical receiving circuit for detecting the signal component from the downstream optical signal received through the optical fiber; and An optical transmission circuit for transmitting, toward the optical fiber, the upstream optical signal obtained by modulating a part of the signal with the upstream signal by a saturation amplification / attenuation circuit.
  • Optical transmission This is the transmission method.
  • the sixth invention of the present application is the bidirectional optical transmission system according to the fifth invention, in which a master device and a plurality of slave devices are transmitted in a direction-multiplexed bidirectional one-wavelength multiplex multipoint manner using a single optical fiber.
  • An attenuating circuit which is a semiconductor optical amplifier, which coats a film having a higher reflectivity than a cleavage state on an end surface facing the incident end surface of the downstream optical signal, from the incident end surface of the downstream optical signal;
  • This is a bidirectional optical transmission system characterized by a reflection type configuration for transmission.
  • a seventh invention of the present application is directed to a bidirectional optical fiber bidirectional / wavelength-time-division multiplexed bidirectional transmission between a master device and a plurality of slave devices using a first optical fiber and a second optical fiber.
  • the master device separates each downstream optical signal obtained by superimposing a bias component on a signal component modulated by a downstream signal into a wavelength and a time domain for each slave device and directs the separated downstream optical signal to the first optical fiber.
  • An optical receiving circuit that detects the signal component from the downstream optical signal received through the first optical fiber; anda part of the received downstream optical signal is modulated with the upstream signal by a saturation amplification / attenuation circuit.
  • An optical transmission circuit for transmitting the upstream optical signal to the second optical fiber.
  • the eighth invention of the present application is a two-core optical fiber bidirectional / wavelength time-division multiplexing multi-point optical system using a first optical fiber and a second optical fiber between a master device and a plurality of slave devices according to the seventh invention of the present application.
  • a wavelength tunable light source capable of changing the wavelength of an optical output to the wavelength of each slave device is used for the optical transmission circuit.
  • the ninth invention of the present application is directed to a bidirectional optical system in which a main unit and a plurality of slave units are transmitted in a single-core optical fiber in a direction-division multiplexed / wavelength time division multiplexed multipoint transmission.
  • the master device separates each downstream optical signal obtained by superimposing a bias component on a signal component modulated by a downstream signal into a wavelength and a time domain for each slave device and transmits the separated optical signal to the optical fiber.
  • An optical transmitting circuit, and at least one optical receiving circuit that detects an upstream signal from each upstream optical signal received through the optical fiber, wherein the plurality of slave devices each receive the downstream signal received through the optical fiber.
  • An optical receiving circuit for detecting the signal component from the optical signal; and transmitting the upstream optical signal, which is obtained by modulating a part of the received downstream optical signal with the upstream signal by a saturation amplification / attenuation circuit, toward the optical fiber.
  • a bidirectional optical transmission system characterized by comprising an optical transmission circuit.
  • a tenth invention of the present application is the ninth invention of the present application, wherein the main device and the plurality of slave devices are transmitted in a single-core optical fiber in a directional multiplex bidirectional / wavelength time division multiplex multipoint transmission system.
  • a saturating amplification / attenuation circuit which is a semiconductor optical amplifier, wherein a coating having a higher reflectivity than a cleavage state is coated on an end face opposed to an incident end face of the downstream optical signal; This is a bidirectional optical transmission system that is characterized by a reflection-type configuration for transmission from an optical network.
  • An eleventh invention of the present application relates to a ninth invention of the present invention, which relates to a bidirectional optical transmission system in which a main device and a plurality of slave devices are transmitted in a direction multiplexed bidirectional / wavelength time division multiplexed multipoint using a single optical fiber.
  • a bidirectional optical transmission system characterized in that a wavelength-variable light source capable of changing a wavelength of an optical output to a wavelength of each slave device is used for the optical transmission circuit.
  • a twelfth invention of the present application is directed to an optical transmission system for transmitting a second optical signal, which is obtained by modulating a part of a received first optical signal with a second transmission signal by a saturation amplification / attenuation circuit, to an optical fiber.
  • An optical transmitting and receiving apparatus comprising: an optical receiving circuit that detects a signal component from a signal.
  • a thirteenth invention of the present application is directed to an optical receiving circuit for receiving an optical signal obtained by superimposing a bias component on a signal component modulated by a signal through an optical fiber, and a part of the optical signal received by a saturation amplification / attenuation circuit.
  • An optical transmitting and receiving apparatus comprising: an optical transmitting circuit that modulates a signal to be transmitted and transmits the modulated signal to an optical fiber.
  • the fourteenth invention of the present application is the optical transmission / reception device according to the twelfth invention, wherein the bias component is at least 50%, preferably at least 100% of the signal component.
  • An optical transceiver is the optical transmission / reception device according to the twelfth invention, wherein the bias component is at least 50%, preferably at least 100% of the signal component.
  • the fifteenth invention of the present application is the optical transmission / reception device according to the thirteenth invention of the present application, wherein the saturation amplification / attenuation circuit modulates an optical signal with an amplification unit that controls an amplification degree by a control current and a signal to be transmitted.
  • An optical transmitting and receiving apparatus characterized by being a semiconductor optical amplifier having a modulating unit for performing the operation.
  • the sixteenth invention of the present application is the optical transmission / reception device according to the thirteenth invention of the present application, wherein the saturation amplification / attenuation circuit includes an amplification unit that saturates with a control current and a modulation that absorbs an optical signal with a signal to be transmitted. And a semiconductor optical element having a portion.
  • the saturation amplification / attenuation circuit linearly amplifies in the range where the optical input is small. This is a circuit where the light output is constant regardless of the level. Further, the amplification degree is controllable, so that the amplification degree can be increased to perform saturation amplification, or conversely, the amplification degree can be suppressed and attenuated. Note that the attenuation in the saturation amplification / attenuation circuit includes that in which the degree of amplification is simply reduced.
  • Two-core optical fiber bidirectional transmission refers to a technology for bidirectional transmission using a first optical fiber for transmitting downstream optical signals and a second optical fiber for transmitting upstream optical signals.
  • Single-core optical fiber direction multiplex bidirectional transmission means that the same optical fiber is used for transmission of downstream optical signals and upstream optical signals, and an optical multiplexing / branching circuit is used to join and branch downstream optical signals and upstream optical signals having the same wavelength.
  • Two-core optical fiber bidirectionalWavelength multiplexing multipoint transmission refers to a transmission method in which a main unit and a plurality of slave units are connected in a 1-to-N multipoint connection, and the first optical fiber is used to transmit downstream optical signals.
  • the second optical fiber is used for transmission of the upstream optical signal, and different wavelengths are assigned to the upstream optical signal and the downstream optical signal for each slave device.
  • This is a technology to perform bidirectional transmission by wavelength multiplex transmission between them.
  • Single-core optical fiber direction multiplexing bidirectional / wavelength multiplexing multipoint transmission refers to the transmission of downstream optical signals and the transmission of upstream optical signals in a transmission system in which a main unit and a plurality of slave units are connected in a 1: N multipoint connection.
  • the same optical fiber is used, the upstream optical signal and the downstream optical signal have the same wavelength, and different wavelengths are assigned to each slave device, and wavelength multiplex transmission is performed between the main device and the wavelength multiplexing circuit provided in the optical fiber.
  • This is a technology for bidirectional transmission.
  • Two-way optical fiber bi-directional wavelength-division multiplexing multipoint transmission is a transmission method in which a master unit and a plurality of slave units are connected in a 1: N multipoint connection.
  • the second optical fiber is used for transmission of the upstream optical signal, and a different wavelength and time domain are assigned to each of the slave optical devices for the upstream optical signal and the downstream optical signal.
  • This is a technology that performs wavelength multiplex transmission between provided wavelength multiplexing circuits and bidirectional transmission.
  • Single-core optical fiber direction multiplexing bidirectional ⁇ Wavelength time division multiplexing multipoint transmission refers to the transmission of downstream optical signals and upstream optical signals in a transmission system in which a master unit and multiple slave units are connected in a 1: N multipoint connection.
  • the same optical fiber is used for transmission, the upstream optical signal and the downstream optical signal have the same wavelength, and a different wavelength and time domain are assigned to each slave device.
  • This is a technology for bidirectional transmission by wavelength multiplex transmission between circuits.
  • FIG. 1 is a configuration diagram of a bidirectional optical transmission system showing an embodiment of the present invention.
  • FIG. 2 is an operation diagram of the bidirectional optical transmission system of the present invention.
  • FIG. 3 is an operation diagram of the bidirectional optical transmission system of the present invention.
  • FIG. 4 is a configuration diagram of a bidirectional optical transmission system showing an embodiment of the present invention.
  • FIG. 5 is a configuration diagram of a bidirectional optical transmission system showing an embodiment of the present invention.
  • FIG. 6 is a configuration diagram of a bidirectional optical transmission system showing an embodiment of the present invention.
  • FIG. 7 is a configuration diagram of a bidirectional optical transmission system showing an embodiment of the present invention.
  • FIG. 8 is a schematic structural diagram of an output intensity saturated amplification modulator according to an embodiment of the present invention.
  • FIG. 9 is a schematic structural diagram of an output intensity saturated amplification modulator showing an embodiment of the present invention.
  • FIG. 10 is a schematic sectional view of an output-intensity-saturated amplification modulator with a reflective film according to an embodiment of the present invention.
  • FIG. 11 is a schematic sectional view of an output-intensity-saturated amplification modulator with a reflective film according to an embodiment of the present invention.
  • FIG. 12 is a configuration diagram of an optical transmitting and receiving apparatus including an output intensity saturated amplification modulator with a reflection film.
  • FIG. 13 is a schematic structural diagram of an output intensity saturated amplification modulator showing an embodiment of the present invention.
  • FIG. 14 is a configuration diagram of a bidirectional optical transmission system showing an embodiment of the present invention.
  • FIG. 15 is a configuration diagram of a bidirectional optical transmission system showing an embodiment of the present invention. It is.
  • Figure 16 is a block diagram of a conventional bidirectional optical transmission system.
  • Figure 17 is an operation diagram of the conventional bidirectional optical transmission system.
  • FIG. 18 is a configuration diagram of a conventional bidirectional optical transmission system.
  • the description of reference numerals in the figure is as follows.
  • 1 1, 1 1 — 1, 1 1 1 2, 1 1 1 N is the optical transmission circuit of the main unit
  • 1 2, 1 2 — 1, 1 2 — 2, 1 2 1 N is the optical reception circuit of the main unit
  • 1 3, 1 3-1, 1 3 _ 2 are main unit wavelength multiplexing circuits
  • 14, 14-1, 14-2, 14 4 N are main unit optical coupling / branching circuits
  • 15, 1 5-1, 15-2 is an optical fiber
  • 16-16 is 1, 1-16 is a wavelength division multiplexing circuit, 17-17-1, 17-2, 17-1 N is a slave device
  • 18, 18-1, 18-2, 18 -N is the optical receiving circuit of the slave device
  • 19, 19-1, 19-2, 19-1 N is the slave device
  • An optical transmission circuit 21 is an optical branching circuit
  • 22 is an optical receiving unit
  • 23 is
  • 3 4 is an output port
  • 3 5 is an amplifying section
  • 3 is a modulating section
  • 3 7 is an output intensity saturated amplifying modulator with a reflective film
  • 3 8 is an output intensity saturated amplifying modulator with a reflective film
  • 3 9 Is the entrance / exit port
  • 40 is the reflective film
  • 41, 4 1-1, 41-2, 41-N is the optical transmission circuit of the main unit
  • 42, 42-1, 42-2, 4 2—N is the optical receiving circuit of the main unit
  • 43 is the optical receiving unit
  • 44 is the optical transmitting unit
  • 45-1, 45-2 is the wavelength multiplexing circuit of the main unit
  • 48_N is the optical receiver circuit of the slave device
  • 49, 49 ⁇ 1, 49 ⁇ 2, 49 ⁇ 1 N is the optical transmitter circuit of the slave device
  • 61 is the output intensity saturated amplifier
  • the modulator, 62 is a saturation amplification section
  • 63 is a modulation section
  • 64 is a semiconductor active
  • the present embodiment is a bidirectional optical transmission system for bidirectional transmission of a two-core optical fiber.
  • FIG. 1 shows the configuration of the embodiment of the present invention.
  • 11 is an optical transmission circuit of the main unit
  • 12 is an optical receiving circuit of the main unit
  • 15-1 and 15-2 are optical fibers
  • 18 is an optical receiving circuit of the slave unit
  • 19 is an optical receiving circuit of the slave unit.
  • 21 is an optical splitter / branch circuit
  • 22 is an optical receiver
  • 23 is a drive unit
  • 24 is an output intensity saturated modulator as a saturation amplification / attenuation circuit. .
  • FIG. 1 (a) the optical transmission circuit 11 of the main unit transmits a downstream optical signal through the optical fiber 15-1, and the optical reception circuit 18 of the slave unit receives the downstream optical signal.
  • the optical transmission circuit 19 of the slave device transmits an upstream optical signal through the optical fiber 15-2, and the optical reception circuit 12 of the master device receives the upstream optical signal.
  • Fig. 1 (b) shows the head-end configuration of the optical receiving circuit # 8 and the optical transmitting circuit 19 of the slave device.
  • FIG. 1B in the optical receiving circuit 18 of the slave device, the downstream optical signal received via the optical fiber 15-1 is split into two by the optical splitting circuit 21.
  • the branched downstream optical signal is detected by the optical receiving unit 22, and the detected downstream signal is subjected to signal processing in the optical receiving circuit 18.
  • the output intensity saturated amplification modulator 24 saturates and attenuates a part of the branched down optical signal with the up signal from the drive unit 23, and modulates it into the up optical signal.
  • the modulated upstream optical signal is transmitted via the optical finos I5-2.
  • Figure 2 shows the transmission and reception operations of the downstream optical signal
  • Figure 3 shows the transmission and reception operations of the upstream optical signal.
  • a bias component is superimposed on a signal component modulated by a downstream signal to obtain a drive current for a light emitting element (FIG. 2 (a)).
  • the light output of the light-emitting element has a substantially linear relationship with the drive current ( Figure 2 (b)).
  • the optical transmission circuit of the main unit transmits a downstream optical signal output close to the drive current waveform (Fig. 2 (c)).
  • a threshold is set for the signal component of the optical receiver circuit input, and the signal component of the downstream signal is detected (Fig. 2 (d)).
  • the downlink signal is transmitted and received after being intensity-modulated, but may be a modulation format such as phase modulation or frequency modulation.
  • the optical transmission circuit of the main device transmits a signal component with a bias component superimposed thereon, and the optical reception circuit of the slave device detects a downstream optical signal component from the signal component.
  • a part of the downstream optical signal is branched and input to the output intensity saturated amplifier (Fig. 3 (a)).
  • the output-saturation-type amplifying modulator performs linear amplification in the range where the optical input is small, but as the optical input increases, the amplification level saturates and the optical output becomes constant regardless of the optical input level (Fig. 3 (b)).
  • the output intensity saturation amplification modulator is an amplification modulator whose amplification degree can be controlled from the control terminal.It can increase the amplification degree and perform the saturation amplification, or conversely, suppress the amplification degree and attenuate it. (Fig. 3 (b)).
  • the bias component is amplified by the saturation amplification because the bias component is superimposed on the signal component of the downstream optical signal, and the signal component is compressed.
  • the amplification degree is controlled according to the upstream signal.
  • the bias component is generated during the saturation amplification.
  • a high-output optical signal that is amplified and the signal component is compressed is output, and a low-output optical signal is output in which both the bias component and the signal component are compressed during attenuation when the amplification is suppressed (Fig. 3 ( c)).
  • the optical receiver circuit of the main unit sets a threshold value for the signal component input to the optical receiver circuit and detects the signal component of the upstream optical signal (Fig. 3 (d)).
  • the optical power of the bias component is equal to or more than the average optical power of the signal component. Become out It becomes easy to amplify the bias component by the power intensity saturation type amplification modulator.
  • the optical power of the bias component becomes equal to or higher than the peak optical power of the signal component, and the bias component is amplified by the output intensity saturated amplification modulator. Becomes easier. The same applies to the following embodiments.
  • the optical transmission circuit of the main device transmits the downstream optical signal in which the bias component is superimposed on the signal component modulated by the downstream signal to the optical fiber, and the optical transmission circuit of the slave device receives one of the received downstream optical signals.
  • the slave device By transmitting an upstream optical signal whose section is modulated by an upstream signal by a saturation amplification / attenuation circuit, the slave device was able to perform bidirectional transmission without using a light emitting element.
  • the present embodiment is a bidirectional optical transmission system in which directional multiplex bidirectional transmission is performed using a single-core optical fiber.
  • FIG. 4 shows the configuration of the embodiment of the present invention.
  • 11 is the optical transmission circuit of the main device
  • 12 is the optical receiving circuit of the main device
  • 14 is the optical coupling / branching circuit of the main device
  • 15 is an optical fiber
  • 17 is the optical coupling / branching circuit of the slave device
  • 18 is the optical receiver circuit of the slave device
  • 19 is the optical transmitter circuit of the slave device
  • 21 is the optical branching circuit
  • 22 is the optical receiver
  • 23 is the driver
  • 24 is the saturation amplification / attenuation circuit. This is an output intensity saturated amplification modulator.
  • Fig. 4 (a) shows the configuration of the bidirectional transmission method between the master device and the slave device.
  • the optical transmission circuit 11 of the main unit transmits a downstream optical signal through the optical coupling / branching circuit 14 of the main unit and the optical fiber 15, and the optical reception circuit 18 of the slave unit is connected to the slave unit.
  • the downstream optical signal is received through the optical coupling / branching circuit 17.
  • the optical transmission circuit 19 of the slave device transmits an upstream optical signal through the optical multiplexer / demultiplexer circuit 17 of the slave device and the optical fiber 15, and the optical receiver circuit 12 of the main device transmits the upstream optical signal through the optical multiplexer / demultiplexer circuit of the master device. Receive the signal.
  • FIG. 4 (a) shows the configuration of the bidirectional transmission method between the master device and the slave device.
  • FIG. 4 (b) shows the head-end configuration of the optical receiving circuit 18 and the optical transmitting circuit 19 of the slave device.
  • the downstream optical signal received by the optical branching circuit 21 via the optical combining / branching circuit 17 of the slave device is branched into two.
  • the branched down optical signal is detected by the optical receiving unit 22, and the detected down signal is processed in the optical receiving circuit 18.
  • the output-intensity-saturation-type amplifying modulator 24 amplifies and attenuates a part of the branched down optical signal with the up signal from the drive unit 23, attenuates it, and modulates the up light signal.
  • the modulated upstream optical signal is transmitted via the optical multiplexing / branching circuit 17 of the slave device and the optical fiber 15.
  • the optical branching circuit 17 and the optical branching circuit 21 may be integrally formed.
  • the operation of transmitting and receiving downstream optical signals is the same as in Fig. 2, and the operation of transmitting and receiving upstream optical signals is the same as in Fig. 3.
  • the difference is that the provision of the optical coupling / branching circuits 14 and 17 in the master device and the slave device respectively enables bidirectional transmission with a single-core optical fiber.
  • These optical couplers separate the upstream optical signal from the downstream optical signal.
  • a directional optical coupling circuit, an optical circuit, or the like can be applied to the optical coupling / branching circuit.
  • the optical transmission circuit and the optical reception circuit of the main device, and the optical transmission circuit and the optical reception circuit of the slave device operate in the same manner as in the first embodiment.
  • a downstream signal and an upstream signal are transmitted on the same optical fiber at the same wavelength. Therefore, when the main unit receives an upstream signal, it may interfere with a downstream signal reflected in the middle of the optical fiber.
  • the spectrum width of the downstream signal light can be widened. When the spectrum width of the signal light is widened, mutual interference between the upstream signal and the downstream signal reflected in the middle of the line is suppressed, and noise added to the upstream signal can be suppressed.
  • the optical transmission circuit of the master device transmits a downstream optical signal in which a bias component is superimposed on the signal component modulated by the downstream signal to the optical fiber, and a part of the downstream optical signal received by the optical transmission circuit of the slave device is saturated.
  • Amplification / attenuation circuit By using a configuration in which the upstream optical signal modulated by the upstream signal is transmitted to the optical fiber, the slave device can perform bidirectional transmission without using a light emitting element.
  • the optical transmission circuit of the slave device transmits an upstream optical signal having the same wavelength as the downstream optical signal by using the output intensity-saturated amplifying modulator, even if the characteristics of the optical multiplexing / demultiplexing circuit have wavelength dependence, the upstream optical signal is transmitted. It is no longer necessary to control and maintain the signal wavelength with high precision.
  • the type of slave device is not different for each wavelength, but the same type of slave device is optional.
  • the present invention can be applied to a slave device. In other words, interoperability (interoperability) between slave devices has become possible.
  • the present embodiment is a bidirectional optical transmission system in which a two-core optical fiber bidirectional / wavelength multiplex multipoint transmission is performed between a main device and a plurality of slave devices.
  • FIG. 5 shows the configuration of the embodiment of the present invention.
  • 1 1 _ 1 to 1 1 1 N are the optical transmission circuit of the main unit
  • 1 2 — 1 to 1 2 — N are the optical reception circuit of the main unit
  • 13 1 and 1 3 2 are the main units.
  • 15-1 and 15-2 are optical fibers
  • 16-1 and 16-2 are wavelength-division multiplexing circuits provided in the middle of the optical fiber
  • 18-8 :! 1 18 —N is the optical receiving circuit of the slave
  • 19 _ 1 to 19 — N is the optical transmitting circuit of the slave.
  • the symbol N is used to represent two or more.
  • the optical transmission circuits 11 1 1 to 11 1 N represent two or more optical transmission circuits.
  • the downward arrow indicates the downward transmission direction
  • the upward arrow indicates the upward transmission direction.
  • a plurality of optical transmission circuits 11 1 to 11 N of the main unit are configured to superimpose a bias component on a signal component modulated by the downstream signal and to transmit each downstream optical signal to the wavelength multiplexing circuit 1 of the main unit.
  • 3 Send to 1.
  • the wavelength division multiplexing circuit 13-1 converts the downstream optical signals of different wavelengths ( ⁇ ⁇ ⁇ ! ⁇ ) Transmitted from the plurality of optical transmission circuits 111-1-11 to the optical fiber 15-1. Multiplex.
  • the wavelength multiplexing circuit 16 _ 1 provided in the middle of the optical fino 15-1 separates the wavelength of each downstream optical signal toward each slave device according to the wavelength.
  • the optical receiving circuits 18-1 to 18- ⁇ of each slave device detect signal components from the downstream optical signal received through the optical fiber 15-1.
  • the optical transmission circuit of each slave device 1 9 1:! 1-19 transmits an upstream optical signal, which is obtained by modulating a part of the received downstream optical signal with an upstream signal by a saturation amplification / attenuation circuit, to an optical fiber 15-2.
  • the wavelength multiplexing circuit 16-2 provided in the middle of the optical fiber 15-2 is composed of a plurality of optical transmission circuits 1 9
  • the wavelength division multiplexing circuit 1 3-2 of the main unit is transmitted from the optical transmission circuit of multiple slave units 1 9-:! ⁇ 1 9-N
  • the upstream optical signals of different wavelengths are transmitted for each wavelength to the optical receiver circuit 1 2 of the main unit.
  • 1 1 2 Separate the wavelength toward ⁇ .
  • the plurality of optical receiver circuits 12-1 to 12-2 in the main unit detect upstream signals from the received upstream optical signals.
  • the operation of transmitting and receiving downstream optical signals is the same as in Fig. 2, and the operation of transmitting and receiving upstream optical signals is the same as in Fig. 3.
  • the main unit has wavelength multiplexing circuits 13-1 and 13-2, and the wavelength multiplexing circuits 16-1 and 16-2 in the middle of the optical fiber.
  • wavelength multiplexing multipoint transmission has become possible.
  • the upstream optical signal and the downstream optical signal are multiplexed and demultiplexed by the wavelength multiplexing circuits 16-1 and 16-2.
  • the optical transmission circuit and the optical reception circuit of the main device, and the optical transmission circuit and the optical reception circuit of the slave device operate in the same manner as in the first embodiment.
  • the optical transmission circuit of the master device transmits a downstream optical signal in which a bias component is superimposed on the signal component modulated by the downstream signal to the optical fiber, and a part of the downstream optical signal received by the optical transmission circuit of the slave device is saturated.
  • the slave device can perform bidirectional transmission without using a light emitting element.
  • the optical transmission circuit of the slave device transmits an upstream optical signal having the same wavelength as the downstream optical signal by the output intensity saturated amplification modulator, the transmission circuit of the slave device on the wavelength characteristic of the wavelength multiplexing circuit It is no longer necessary to match or maintain the wavelength of the upstream optical signal with high precision.
  • the type of slave device is not different for each wavelength, but the same type of slave device is optional.
  • the present invention can be applied to a slave device. In other words, interoperability (interoperability) can be secured between slave devices.
  • the present embodiment is a bidirectional optical transmission system in which a master device and a plurality of slave devices transmit one-core optical fiber in a direction multiplex bidirectional / wavelength multiplex multipoint transmission.
  • FIG. 6 shows the configuration of the embodiment of the present invention.
  • 1 1-1-: 1 1-N is the optical transmission circuit of the main unit
  • 1 2 _ 1-12 _ N is the optical receiving circuit of the main unit
  • 1 3-1, 1 3-2 is the main unit
  • 14 is an optical multiplexing / branching circuit of the main device
  • 15 is an optical fiber
  • 16 is a wavelength multiplexing circuit provided in the middle of the optical fiber
  • ⁇ 1 7 — N is the optical coupling / branching circuit of the slave device
  • 1 8 —:! 1 18 —N is the optical receiver circuit of the slave device
  • 19 — 1 to 19 _N is the optical transmitter circuit of the slave device.
  • the symbol N is used to represent two or more.
  • the optical transmission circuits 11-1 to 11_N represent two or more optical transmission circuits.
  • the downward arrow indicates the downward direction
  • the upward arrow indicates the upward direction
  • the up and down directions indicate the upward and downward bidirectional transmission directions.
  • a plurality of optical transmission circuits 1 1 1 1 1 to 1 1 1 N of the main unit transmit each downstream optical signal obtained by superimposing a bias component on a signal component modulated by a downstream signal, to a wavelength multiplexing circuit 1 of the main unit.
  • Optical transmitter circuit 1 1 - 1 to 1 1 _ wavelength of the downstream optical signal of N is previously assigned ( ⁇ 1 ⁇ 2, ⁇ ⁇ ⁇ ⁇ ).
  • the wavelength multiplexing circuit 13-1 of the main unit wavelength-multiplexes downstream optical signals of different wavelengths ( ⁇ to! ⁇ ) Transmitted from the plurality of optical transmission circuits 11-1 to 11_ ⁇ .
  • the optical combining / branching circuit 14 of the main device combines these downstream optical signals with the optical fiber 15_1.
  • the wavelength multiplexing circuit 16 provided in the middle of the optical fiber 15 separates each downstream optical signal toward each slave device according to the wavelength.
  • Optical coupling / branching circuit of each slave device 1 7 —:! 1 1 7 — ⁇ is an optical receiving circuit that supports downstream optical signals 1 8 —:! ⁇ 1 8 — branch to ⁇ .
  • the optical transmission circuit of each slave device 1 9 1:! In 1910, a part of the received optical signal is branched by an optical branching circuit (not shown), and an upstream optical signal modulated by an upstream signal by a saturation amplification / attenuation circuit is transmitted.
  • the optical branching circuit 17 for branching a part of the downstream optical signal and the optical combining / branching circuit 17 may be integrally configured. Since the downstream optical signal is saturated and amplified by the output intensity saturation amplification modulator of the optical transmission circuit of the slave device, the wavelength to be transmitted is the same as the downstream optical signal.
  • Optical coupling / branching circuit of slave device 1 7 —:! 1 1 7 — ⁇ joins the upstream optical signal to the optical fiber 15.
  • the wavelength division multiplexing circuit 16 provided in the middle of the optical fiber 15 is composed of a plurality of optical transmission circuits 19 1:! 1 1 9 — Wavelength multiplexes upstream optical signals of different wavelengths ( ⁇ to! ⁇ ) Transmitted from ⁇ toward the main unit.
  • the wavelength multiplexing circuits 13 1 and 12 of the main unit transmit upstream optical signals of different wavelengths ( ⁇ ;! To ⁇ ⁇ ) transmitted from the optical transmission circuits 19 _ 1 to 19 In the main unit, the wavelength is separated toward the optical receiver circuit 12-1-1 2-—.
  • Multiple of main units The optical receiving circuits 1 2-1 to 1 2 -N respectively detect upstream signals from the received upstream optical signals.
  • the operation of transmitting and receiving downstream optical signals is the same as in Fig. 2, and the operation of transmitting and receiving upstream optical signals is the same as in Fig. 3.
  • the difference is that the wavelength division multiplexing circuits 13 _ 1 and 13 _ 2 and the optical multiplexing / branching circuit 14 are provided in the main unit, the wavelength multiplexing circuit 16 is provided in the middle of the optical fiber, and the optical multiplexing and branching circuit 17 is provided in a plurality of slave units.
  • — 2 to 17 — N means that single-core optical fiber direction multiplexing bidirectional and wavelength multiplexing multipoint transmission is possible between the main unit and multiple slave units.
  • a plurality of upstream optical signals and a plurality of downstream optical signals are multiplexed or demultiplexed by these wavelength multiplexing circuits and optical multiplexing / branching circuits.
  • optical transmission circuit and the optical reception circuit of the slave device operate in the same manner as in the first embodiment.
  • a downstream signal and an upstream signal are transmitted on the same optical fiber with the same wavelength. Therefore, when an upstream signal is received by the main unit, it may interfere with a downstream signal reflected in the middle of an optical fiber.
  • the drive current of the light emitting element is controlled so that the signal component is superimposed on the downstream signal, so that the spectrum width of the downstream signal light can be increased.
  • the spectrum width of the signal light is widened, mutual interference between the upstream signal and the downstream signal reflected in the middle of the line is suppressed, and noise added to the upstream signal can be suppressed.
  • the optical transmission circuit of the master device transmits a downstream optical signal in which a bias component is superimposed on the signal component modulated by the downstream signal to the optical fiber, and a part of the downstream optical signal received by the optical transmission circuit of the slave device is saturated.
  • the slave device can perform bidirectional transmission without using a light emitting element.
  • the optical transmission circuit of the slave device is output-saturation type amplification modulator.
  • the transmission circuit on the slave device side matches or maintains the wavelength of the upstream optical signal with high accuracy with respect to the wavelength characteristics of the wavelength multiplexing circuit. The need is gone.
  • the type of slave device is not different for each wavelength, but the same type of slave device is optional.
  • the present invention can be applied to a slave device. In other words, interoperability (interoperability) between slave devices has become possible.
  • the present embodiment is a bidirectional optical transmission system in which a single device and a plurality of slave devices perform single-core optical fiber direction multiplex bidirectional / wavelength multiplex multipoint transmission.
  • FIG. 7 shows the configuration of the embodiment of the present invention.
  • 1 1 1 to 1 1 —N is the optical transmission circuit of the main unit
  • 1 2 — 1 to 1 2 —N is the optical receiving circuit of the main unit
  • 13 is the wavelength multiplexing circuit of the main unit
  • 1 41 :! ⁇ 14 1 N is the optical branching circuit of the main unit
  • 15 is the optical fiber
  • 16 is the wavelength multiplexing circuit provided in the middle of the optical fiber
  • 1 7-:! ⁇ 1 7 — N is the optical coupling / branching circuit of the slave
  • .About.18-N is an optical receiving circuit of the slave device
  • 19-11-1-19-N is an optical transmitting circuit of the slave device.
  • the symbol N is used to represent two or more.
  • the optical transmission circuits 11_1 to 11-N represent two or more optical transmission circuits.
  • the downward arrow indicates the downward direction
  • the upward arrow indicates the upward direction
  • the up and down directions indicate the upward and downward bidirectional transmission directions.
  • Embodiment 4 The configuration and operation of a system for performing bidirectional transmission between a master device and a plurality of slave devices will be described.
  • the difference from Embodiment 4 is the arrangement of the optical multiplexing / branching circuit and the wavelength multiplexing circuit of the main device. That is, the connection between the wavelength multiplexing circuit and the optical multiplexing / branching circuit of the main device is reversed from that of the fourth embodiment. Since the optical multiplexing / branching circuit and the wavelength multiplexing circuit are both linear circuits, the same operation is performed even if the order of connection is changed.
  • Embodiment 4 or Embodiment 5 depending on the optical loss and required number of optical coupling / branching circuits and wavelength division multiplexing circuits Is selected.
  • a downstream signal and an upstream signal are transmitted on the same optical fiber with the same wavelength. Therefore, when the main unit receives an upstream signal, it may interfere with a downstream signal reflected in the middle of the optical fiber.
  • the drive current of the light emitting element is controlled so that the signal component is superimposed on the downstream signal, so that the spectrum width of the downstream signal light can be increased.
  • the spectrum width of the signal light is widened, mutual interference between the upstream signal and the downstream signal reflected in the middle of the line is suppressed, and noise added to the upstream signal can be suppressed.
  • the optical transmission circuit of the master device transmits a downstream optical signal in which a bias component is superimposed on the signal component modulated by the downstream signal to the optical fiber, and a part of the downstream optical signal received by the optical transmission circuit of the slave device is saturated.
  • the slave device can perform bidirectional transmission without using a light emitting element.
  • the optical transmission circuit of the slave device transmits an upstream optical signal having the same wavelength as the downstream optical signal by the output intensity saturated amplification modulator, the transmission circuit of the slave device on the wavelength characteristic of the wavelength multiplexing circuit It is no longer necessary to match or maintain the wavelength of the upstream optical signal with high precision.
  • the type of slave device is not different for each wavelength, but the same type of slave device is optional.
  • the present invention can be applied to a slave device. In other words, interoperability (interoperability) between slave devices has become possible.
  • An optical transmission / reception device including an output intensity saturated amplification modulator will be described.
  • An ordinary semiconductor optical amplifier performs optical amplification using a region where output light is linearly amplified with respect to input light.
  • the output intensity saturated amplification modulator In the semiconductor optical amplifier, a region where the intensity of output light is saturated and amplified with respect to input light is positively used and modulation is performed. Since the output intensity-saturated modulator only amplifies the input light, the wavelength of the output light follows the input light.
  • Fig. 8 shows the schematic structure of the output intensity saturated amplification modulator.
  • reference numeral 31 denotes an output intensity saturated amplification modulator
  • reference numeral 33 denotes an amplification modulation section
  • reference numeral 34 denotes an emission port.
  • the input light is subjected to saturation amplification and attenuation by an input signal from a control terminal (not shown) in an amplification modulation section 33.
  • the output light that has been amplified and modulated by the saturation amplification and attenuation is output from the output port 34. In this way, it is possible to modulate with the input signal by the saturation amplification and attenuation.
  • the degree of amplification as an amplifier is determined by the magnitude of the input signal current to the electrodes provided in the amplification modulation section. Increasing the input signal current increases the amplification. In addition, the saturation point at which the intensity of the output light is saturated with respect to the input light also increases at the same time. When the input signal current is reduced, the amplification degree of the input light is reduced or attenuated. When the optical phase is modulated by the input signal current, phase modulation is performed, or when the optical frequency is modulated, frequency modulation is performed.
  • the wavelength of the output light that has been subjected to saturation amplification and modulation is the same as the wavelength of the input light to the output intensity saturation type amplification modulator.
  • FIG. 9 shows a schematic structure of another output intensity saturated amplification modulator.
  • the output intensity saturation amplification modulator described above performed saturation amplification and modulation with one electrode.
  • This output intensity-saturated amplification modulator separates the saturation amplification section from the modulation section. Therefore, the control terminal is also separated into an amplification control terminal and a modulation input terminal.
  • reference numeral 32 denotes an output intensity saturated amplification modulator
  • reference numeral 35 denotes an amplification unit
  • reference numeral 36 denotes a modulation unit
  • reference numeral 34 denotes an output port.
  • the amplification section 35 performs saturation amplification by a control input signal from an amplification control terminal (not shown)
  • the modulation section 36 performs modulation amplification on a modulation input terminal (not shown). Modulation is performed by these modulation input signals.
  • the output light that has been amplified and modulated is output from the output port 34. In this way, by separating the amplifying section and the modulating section, the amplifying and modulating actions can be performed independently of each other.
  • the amplification degree of the amplifier is controlled by the control input signal current to the electrodes provided in the amplifying section. Determined by the size. Increasing the control input signal current increases the amplification. In addition, the saturation point at which the intensity of the output light saturates the input light also increases. By dividing the amplifying unit into a plurality of parts and increasing the degree of amplification in the first stage and decreasing the degree of amplification in the second stage, saturation amplification can be performed efficiently.
  • the modulation section amplifies or attenuates the output light by the modulation input signal current to modulate the intensity. Modulation input Modulation of the optical phase by the signal current results in phase modulation, or modulation of the optical frequency results in frequency modulation.
  • the wavelength of the output light that has been saturated amplified and modulated is the same as the wavelength of the input light to the output intensity saturated amplification modulator.
  • the wavelength of the upstream optical signal can be made to follow the wavelength of the downstream optical signal. This eliminates the need to precisely control and maintain the wavelength of the upstream optical signal in the equipment.
  • An optical transmission / reception device including an output intensity saturated amplification modulator with a reflection film will be described.
  • An ordinary semiconductor optical amplifier performs optical amplification using a region where output light is linearly amplified with respect to input light. Further, the optical signal incident from the entrance of the incident end face is amplified and emitted from the exit of the exit end face facing the incident end face.
  • the output-intensity-saturation-type modulator with a reflection film is a semiconductor optical amplifier in which the region where the intensity of the output light saturates and amplifies with respect to the input light is positively used and modulation is performed.
  • the end face facing the incident end face has higher reflection than the cleavage state.
  • a reflection type configuration in which a film having a refractive index is coated, an optical signal incident from the entrance of the entrance end face is saturated and attenuated, attenuated, reflected by the coated reflective film, and transmitted from the entrance end face of the downstream optical signal. It is.
  • FIG. 10 shows a schematic cross section of an output intensity saturated amplification modulator with a reflection film.
  • 33 is an amplification modulation section
  • 37 is an output intensity saturated amplification modulator with a reflection film
  • 39 is an input / output port
  • 40 is a reflection film.
  • the amplification and modulation section 33 performs saturation amplification and attenuation on the incident light from the input / output port 39 by the input signal.
  • the optical signal amplified and modulated by the saturation amplification and the attenuation is reflected by the reflection film 40 and emitted from the input / output port 39.
  • the emitted optical signal saturates and attenuates the incident light, and its wavelength is the same as that of the incident light.
  • the degree of amplification as an amplifier is determined by the magnitude of the input signal current to the electrodes provided in the amplification modulation section. Increasing the input signal current increases the amplification. Further, the saturation point at which the intensity of the output light is saturated with respect to the input light also increases at the same time. When the input signal current is reduced, the amplification degree of the input light is reduced or attenuated.
  • the optical phase is modulated by the input signal current, phase modulation is performed, or when the optical frequency is modulated, frequency modulation is performed.
  • Fig. 11 shows a schematic cross section of another output intensity-saturated amplification modulator with a reflection film.
  • the output intensity saturation-type amplification modulator described above performed saturation amplification and modulation with one electrode.
  • This output intensity-saturated amplification modulator is one in which the saturation amplification section and the modulation section are separated. Therefore, the control terminal is also separated into an amplification control terminal and a modulation input terminal.
  • reference numeral 35 denotes an amplifying unit
  • 36 denotes a modulating unit
  • 38 denotes an output intensity saturation type amplifying modulator with a reflective film
  • 39 denotes an input / output port
  • 40 denotes a reflective film.
  • the amplification section 35 performs saturation amplification on the incident light from the input / output port 39 by a control input signal from an amplification control terminal (not shown), and modulates the modulation input terminal by a modulation section 36. Modulation is performed using a modulation input signal from a (not shown).
  • the optical signal amplified and modulated by the saturation amplification and attenuation is reflected by the reflection film 40 and emitted from the input / output port 39.
  • the wavelength of the optical signal is the same as that of the incident light because the incident light is saturated and amplified and attenuated.
  • the degree of amplification as an amplifier is determined by the magnitude of the control input signal current to the electrodes provided in the amplifier. Increasing the control input signal current increases the amplification. In addition, the saturation point at which the intensity of the output light saturates the input light also increases. By dividing the amplifying unit into a plurality of parts and increasing the degree of amplification in the first stage and decreasing the degree of amplification in the second stage, saturation amplification can be performed efficiently.
  • the modulation section amplifies or attenuates the output light by the modulation input signal current to modulate the intensity. Modulation input Modulation of the optical phase by the signal current results in phase modulation, or modulation of the optical frequency results in frequency modulation.
  • the output-intensity-saturation-type amplifying modulator 37 or 38 with the reflection film is connected to the optical transmitting / receiving device of the slave device, particularly, the same optical fiber for transmission of the downstream optical signal and transmission of the upstream optical signal described in the embodiment.
  • the wavelength of the upstream optical signal can be made to follow the wavelength of the downstream optical signal, and the wavelength of the upstream optical signal in the slave device can be accurately determined. It is no longer necessary to control or maintain the same.
  • the present embodiment relates to an optical transmitting / receiving device including an output intensity saturated amplification modulator with a reflection film, and a bidirectional optical transmission system using the optical transmitting / receiving device.
  • Fig. 12 shows the configuration of an optical transmitting and receiving device equipped with an output intensity saturation type amplification modulator with a reflection film.
  • 15 is an optical fiber
  • 17 is an optical coupling / branching circuit of a slave device
  • 18 is an optical receiving circuit of a slave device
  • 19 is an optical transmitting circuit of a slave device
  • 22 is an optical receiving unit
  • 23 is an optical receiving unit.
  • the driving unit 37 is an output intensity saturated type amplification modulator with a reflection film.
  • a downstream optical signal transmitted through the optical fiber 15 is partially received by the optical multiplexing / branching circuit 17 and is received by the optical receiving unit of the optical receiving circuit 18.
  • the other downstream optical signals branched by the optical coupler 17 are reflected.
  • the light enters the output-saturation-amplified modulator 37 with a film, and is subjected to saturation amplification and modulation.
  • the returned optical signal propagates through the optical fiber 15 as an upstream optical signal.
  • the wavelength of the returned optical signal is the same as the wavelength of the downstream optical signal.
  • the same effect can be obtained by replacing the output intensity saturated amplification modulator 37 with a reflection film with the output intensity saturation amplification modulator 38 with a reflection film.
  • the output intensity saturated amplifier with reflection film has a common input port and output port, so that the same optical fiber is used for transmission of the downstream optical signal and transmission of the upstream optical signal described in the embodiment. Effective for optical transmission systems.
  • FIG. 12 shows the present embodiment.
  • the optical branch circuit 21 of 4 (b) becomes unnecessary. For this reason, optical loss due to branching is also reduced.
  • the output intensity saturated amplification modulator with the reflection film is used as a slave optical transmission / reception device, in particular, a bidirectional transmission using the same optical fiber for transmission of the downstream optical signal and transmission of the upstream optical signal described in the embodiment.
  • the wavelength of the upstream optical signal can be made to follow the wavelength of the downstream optical signal, and the wavelength of the upstream optical signal in the slave device can be controlled with high precision. And maintenance was no longer necessary.
  • single-core optical fiber direction multiplex bidirectional transmission and single-core optical fiber bidirectional single-wavelength multiplex multipoint transmission systems it was possible to reduce the number of optical branch circuits and reduce optical loss.
  • An optical transmission / reception device including an output intensity saturation amplification modulator having a saturation amplification unit and a modulation unit will be described.
  • the saturation amplifying unit semiconductor optical amplification using a region where the intensity of the output light is saturated and amplified with respect to the input light is used.
  • the modulator uses a semiconductor absorption type modulator that can be driven with a small and low voltage. Absorption type modulation enables high-speed modulation.
  • Fig. 13 shows the schematic structure of the output intensity saturated amplification modulator.
  • 61 is an output intensity saturation type modulator having a saturation amplification section and a modulation section
  • 62 is a saturation amplification section
  • 63 is a modulation section
  • 64 is a semiconductor active layer for realizing semiconductor optical amplification
  • 65 is a semiconductor active layer. Is an absorption modulation layer for realizing modulation.
  • the input signal is subjected to saturation amplification of the input signal in the saturation amplifier 62, the bias component is amplified, the signal component is compressed, and the signal is modulated in the modulator 63.
  • the modulator 63 realizes absorption type modulation and is not limited by the carrier lifetime of the active layer, so that high-speed modulation is possible. In this modulator, the modulation efficiency does not depend on the wavelength of the input light because the absorption edge is set to a shorter wavelength than the wavelength used. /
  • the wavelength of the upstream optical signal can be made to follow the wavelength of the downstream optical signal. It was not necessary to control or maintain the wavelength of the upstream optical signal with high precision.
  • the present embodiment is a bi-directional optical transmission system in which a main unit and a plurality of slave units have two cores.
  • FIG. 14 shows the configuration of the embodiment of the present invention.
  • 25 is the optical transmission circuit of the main unit
  • 26 is the optical receiving circuit of the main unit
  • 15-1 and 15-2 are optical fibers
  • 16-1 and 16-2 are optical fibers
  • Wavelength division multiplexing circuit provided in the middle of 1 18 —N is the optical receiving circuit of the slave
  • 19 1 1 to 19 NN is the optical transmitting circuit of the slave.
  • the symbol N is used to represent two or more.
  • optical transmission circuit 1 1 1:! 1 1 1 —N represents two or more optical transmission circuits.
  • FIG. 14 shows the configuration of the embodiment of the present invention.
  • 25 is the optical transmission circuit of the main unit
  • 26 is the optical receiving circuit of the main unit
  • 15-1 and 15-2 are optical fibers
  • 16-1 and 16-2 are optical fibers
  • the configuration of a system for performing bidirectional transmission between a main device and a plurality of slave devices in which a downward arrow indicates a downward direction and an upward arrow indicates an upward transmission direction, will be described.
  • the optical transmission circuit 25 of the main unit is modulated with a downstream signal.
  • the respective downstream optical signals obtained by superimposing the bias components on the signal components thus transmitted are transmitted to the slave devices.
  • any one of N wavelengths ( ⁇ to ⁇ N ) is assigned to the wavelength of the wavelength variable light source included therein by an external control signal.
  • the assigned wavelength is ⁇ for the optical signal transmitted to the optical receiver circuit 18 — N of the slave device.
  • the optical transmission circuit 25 of the main device transmits an optical signal in a different time domain and wavelength for each slave device.
  • the wavelength multiplexing circuit 16-1 provided in the middle of the optical fiber 15-1 separates each downstream optical signal toward each slave device according to the wavelength.
  • the optical receiving circuits 18-1 to 18- ⁇ of each slave device detect a signal component from the downstream optical signal received through the optical fiber 15-1.
  • the optical transmission circuit 19-1 to 19- ⁇ of each slave device transmits an upstream optical signal, which is obtained by modulating a part of the received downstream optical signal with an upstream signal by a saturation amplification / attenuation circuit, to an optical fiber 15-2. Send to.
  • the wavelength to be transmitted is the same as that of the downstream optical signal because the downstream optical signal is saturated and amplified by the output intensity saturation type amplification modulator of the optical transmission circuit of the slave unit.
  • the wavelength division multiplexing circuit 16-2 provided in the middle of the optical fiber 15-2 is a plurality of optical transmission circuits 19-1 :! 1 1 9 — Wavelength multiplexes upstream optical signals of different wavelengths (A i to A N ) transmitted from ⁇ toward the main unit.
  • the optical receiving circuit 26 of the main device detects an upstream signal from the received upstream optical signal.
  • the time domain is separated for each signal transmitted to the reception circuit of the slave device. Furthermore, the wavelength of the tunable laser is changed for each signal transmitted to the receiving circuit of the slave device. For example, when transmitting to the receiving circuit 18-1 of the slave device, the downstream optical signal is transmitted with the wavelength ⁇ and the time domain t.
  • the operation of modulating the light with the downstream signal is the same as in Fig. 2.
  • the receiving circuit of the slave device that receives data may be changed for each dime slot, or may be for each block in which information of a fixed length is collected.
  • the time domain of the optical signal transmitted to the receiving circuit of a given slave device and the time domain of the optical signal transmitted to the receiving circuit of another slave device may be adjusted in advance according to the distance to a plurality of slave devices, or may be set at a fixed interval.
  • the wavelength- and time-division multiplexed optical signal is separated for each slave device by a wavelength multiplexing circuit 16-1, and the optical receiver circuit 18 for the slave device 18 ::! ⁇ 18-received by N.
  • Optical receiving circuit 1 8 1:! The receiving operation of the downlink signal at ⁇ 18-N is the same as that in Fig. 2 (d).
  • Optical receiving circuit 18-1 to 18-N receives optical signals separated for each wavelength, in other words, for each time domain.
  • the transmission operation of the upstream signal is the same as the saturation amplification and modulation operation shown in FIG. 3, but the transmission optical signal transmits the upstream optical signal when the downstream optical signal reaches each slave device.
  • the upstream optical signal from each slave device is multiplexed by the wavelength multiplexing circuit 16-2 and received by the optical receiving circuit 26 of the master device.
  • the time domain interval is set when transmitting from the master device to the slave device so that the upstream optical signals from the slave devices do not overlap when receiving by the optical receiving circuit 26.
  • the downstream optical signal and the upstream optical signal are transmitted using different optical fibers. By operating in this manner, two-core optical fiber bidirectional • wavelength time division multiplex multipoint transmission is performed.
  • a wavelength multiplexing circuit 13-2 of the main apparatus and optical receiving circuits 12-1 to 12_N of a plurality of main apparatuses are used. Is also good.
  • the time of the optical signal transmitted to the receiving circuit of a given slave device is determined so that the upstream optical signals from each slave device do not overlap regardless of the distance difference from the master device to each slave device. It is not necessary to set the interval between the region and the time region of the optical signal transmitted to the receiving circuit of another slave device.
  • the length of the time domain is not fixed for each slave device, but can be changed according to the amount of information transmitted to each slave device.
  • the optical transmission circuit of the main unit covers the signal component modulated by the downlink signal.
  • the downstream optical signal with the bias component superimposed is transmitted to the optical fiber, and the upstream optical signal obtained by modulating a part of the downstream optical signal received by the optical transmission circuit of the slave device with the upstream signal by the saturation amplification / attenuation circuit is output to the optical fiber.
  • the slave device can perform bidirectional transmission without using a light emitting element.
  • the optical transmission circuit of the slave device transmits the upstream optical signal having the same wavelength as the downstream optical signal by the output intensity saturation type amplifying modulator, so that the wavelength of the upstream optical signal can be accurately determined with respect to the wavelength multiplexing circuit. You no longer need to control or maintain.
  • the type of slave device is not different for each wavelength, but the same type of slave device is optional.
  • the present invention can be applied to a slave device. In other words, interoperability (interoperability) between slave devices has become possible.
  • FIG. 15 shows the configuration of the embodiment of the present invention.
  • 25 is the optical transmission circuit of the main unit
  • 26 is the optical receiving circuit of the main unit
  • 15-1, 15-2 is the optical finos
  • 16-1, and 16-2 are the optical
  • the wavelength multiplexing circuit provided in the middle of the fiber, 18_1 to 18-0, is the optical receiving circuit of the slave device
  • 19_1 to 19-N is the optical transmitting circuit of the slave device.
  • the symbol N is used to represent two or more.
  • the optical transmission circuit 11-1 to 1 l_N represents two or more optical transmission circuits.
  • the optical transmission circuit 25 of the main unit follows each downstream optical signal obtained by superimposing a bias component on a signal component modulated by the downstream signal. Send to device. At that time, in the optical transmission circuit 25 of the main device, the wavelength of the tunable light source included therein is controlled by an external control signal.
  • the wavelength to be allocated is such that the optical signal transmitted to the optical receiving circuit 18-N of the slave device has a wavelength of ⁇ . That is, the optical transmission circuit 25 of the main device transmits an optical signal in a different time domain and wavelength for each slave device.
  • the wavelength multiplexing circuit 16 provided in the middle of the optical fiber 15 separates the wavelength of each downstream optical signal toward each slave device according to the wavelength.
  • the optical receiving circuits 18-1 to 18- ⁇ of each slave device detect a signal component from the downstream optical signal received through the optical fiber 15-1.
  • the optical transmission circuit of each slave device 1 9 1:! 1 1 9 — ⁇ transmits the upstream optical signal, which is obtained by modulating a part of the received downstream optical signal with the upstream signal by the saturation amplification / attenuation circuit, to the optical fiber 15. Since the downstream optical signal is saturated and amplified by the output intensity saturation amplification modulator of the optical transmission circuit of the slave device, the wavelength to be transmitted is the same as the downstream optical signal.
  • the wavelength division multiplexing circuit 16 provided in the middle of the optical fiber 15 is composed of a plurality of optical transmission circuits 19 1:! ⁇ 19 19 Wavelength multiplexing of upstream optical signals of different wavelengths ( ⁇ ⁇ ) transmitted from the receiver to the main unit.
  • the optical receiving circuit 26 of the main device detects an upstream signal from the received upstream optical signal.
  • the time domain is separated for each signal transmitted to the reception circuit of the slave device. Furthermore, the wavelength of the tunable laser is changed for each signal transmitted to the receiving circuit of the slave device. For example, when transmitting to the receiving circuit 18-1 of the slave device, the downstream optical signal is transmitted at the wavelength ⁇ i and the time domain is t.
  • the operation of modulating the light with the downstream signal is the same as in Fig. 2.
  • the receiving circuit of the slave device for receiving may be changed for each time slot, or may be a block in which information of a fixed length is collected.
  • the interval between the time domain of the optical signal transmitted to the reception circuit of a predetermined slave device and the time domain of the optical signal transmitted to the reception circuit of another slave device may be adjusted in advance in accordance with the distance to a plurality of slave devices. Alternatively, they may be spaced at regular intervals.
  • the wavelength-time-division multiplexed optical signal is separated for each slave device by the wavelength multiplexing circuit 16 and received by the optical receiving circuits 18-1 to 18-N of the slave device.
  • the receiving operation of the downlink signal in the optical receiving circuits 18-1 to 18-N is the same as that in FIG.
  • Optical receiving circuit 18 — 1 to 18 — N receives optical signals separated by wavelength, in other words, by time domain.
  • the transmission operation of the upstream signal is the same as the saturation amplification and modulation operation shown in FIG. 3, but the transmission optical signal transmits the upstream optical signal when the downstream optical signal reaches each slave device.
  • the upstream optical signal from each slave device is multiplexed by the wavelength multiplexing circuit 16 and received by the optical receiving circuit 26 of the master device.
  • the time domain interval is set when transmitting from the master device to the slave device so that the upstream optical signals from the slave devices do not overlap when receiving by the optical receiving circuit 26.
  • the downstream optical signal and the upstream optical signal are transmitted using the same optical fiber. By operating in this manner, single-core optical fiber bidirectional / wavelength time division multiplex multipoint transmission is performed.
  • a wavelength multiplexing circuit 13-2 of the main unit and optical receiving circuits 12_1 to 12-N of a plurality of main units are used. Is also good.
  • the time of the optical signal transmitted to the receiving circuit of a given slave device is determined so that the upstream optical signals from each slave device do not overlap regardless of the distance difference from the master device to each slave device. It is not necessary to set the interval between the region and the time region of the optical signal transmitted to the receiving circuit of another slave device.
  • the wavelengths ⁇ 1 to ⁇ ⁇ are not necessary to assign all of the wavelengths ⁇ 1 to ⁇ ⁇ to the wavelengths assigned to each time domain, and they can be changed according to the amount of information transmitted to each slave device. Furthermore, the length of the time domain is not fixed for each slave device, but can be changed according to the amount of information transmitted to each slave device.
  • the optical transmission circuit of the master device transmits the downstream optical signal in which the bias component is superimposed on the signal component modulated by the downstream signal to the optical fiber, and transmits the signal to the slave device.
  • a light-emitting element is used on the slave device side by transmitting the upstream optical signal, which is obtained by modulating a part of the downstream optical signal received by the optical transmission circuit with the upstream signal by the saturation amplification / attenuation circuit, to the optical fiber. Bidirectional transmission could be performed without the need for communication.
  • the optical transmission circuit of the slave device transmits an upstream optical signal having the same wavelength as the downstream optical signal by the output intensity saturated amplification modulator, the wavelength of the upstream optical signal is transmitted to the wavelength multiplexing circuit / optical coupling / branching circuit. There is no longer any need to control or maintain high precision.
  • the type of slave device is not different for each wavelength, but the same type of slave device is optional.
  • the present invention can be applied to a slave device. In other words, interoperability (interoperability) can be secured between slave devices.
  • a downstream signal and an upstream signal are transmitted on the same optical fiber with the same wavelength. Therefore, when the main unit receives an upstream signal, it may interfere with a downstream signal reflected in the middle of the optical fiber.
  • the drive current of the light emitting element is controlled so that the signal component is superimposed on the downstream signal, so that the spectrum width of the downstream signal light can be increased.
  • the spectrum width of the signal light is widened, mutual interference between the upstream signal and the downstream signal reflected in the middle of the line is suppressed, and noise added to the upstream signal can be suppressed.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Optical Communication System (AREA)

Abstract

The optical transmission circuit of a slave device needs no light emitting element, and there is no need to control or maintain, with very high precision, the wavelength of the light emitting element in the optical transmission circuit of a slave device. In a bidirectional optical transmission system for allowing bidirectional transmission between a main device and a slave device, the main device comprises an optical transmission circuit for transmitting, to the slave device, a downstream optical signal obtained by superimposing a bias component on a signal component modulated with a downstream signal; and an optical reception circuit for detecting an upstream signal from an upstream optical signal transmitted from the slave device. The slave device comprises an optical reception circuit for detecting a signal component from a downstream optical signal transmitted from the master device; and an optical transmission circuit for transmitting, to the main device, an upstream optical signal obtained by modulating a part of a downstream optical signal with an upstream signal by use of a saturated amplification/attenuation circuit.

Description

明 細 書  Specification
双方向光伝送方式及び光送受信装置 技術分野 Bidirectional optical transmission system and optical transceiver
本発明は、 主装置と従装置との間を光ファイバで双方向伝送する 双方向光伝送方式、 及び光送受信装置に関する。 背景技術  The present invention relates to a bidirectional optical transmission system for bidirectionally transmitting an optical fiber between a master device and a slave device, and an optical transceiver. Background art
従来の双方向光伝送方式の構成を図 1 6に示す。 図 1 6において 、 1 5 — 1、 1 5— 2は光ファイバ、 4 1は主装置の光送信回路、 4 2は主装置の光受信回路、 4 3は光受信部、 4 4は光送信部、 4 8は従装置の光受信回路、 4 9は従装置の光送信回路である。  Figure 16 shows the configuration of a conventional bidirectional optical transmission system. In FIG. 16, 15-1 and 15-2 are optical fibers, 41 is an optical transmission circuit of a main unit, 42 is an optical receiving circuit of a main unit, 43 is an optical receiving unit, and 44 is an optical transmission unit. Reference numeral 48 denotes an optical receiving circuit of the slave device, and 49 denotes an optical transmitting circuit of the slave device.
主装置と従装置で双方向伝送する方式の構成について図 1 6 ( a ) で説明する。 図 1 6は主装置と従装置との間を 2芯の光ファイバ で双方向伝送する双方向光伝送方式である。 即ち、 図 1 6 ( a ) に 示すように、 主装置の光送信回路 4 1 と従装置の光受信回路 4 8 と の間、 及び従装置の光送信回路 4 9 と主装置の光受信回路 4 2 との 間は 2芯の光ファイバ 1 5 _ 1 と 1 5 — 2で接続され、 双方向伝送 する。 図 1 6 ( a ) において、 主装置の光送信回路 4 1は光フアイ バ 1 5 — 1 を通して下り光信号を送信し、 従装置の光受信回路 4 8 はその下り光信号を受信する。 従装置の光送信回路 4 9は光フアイ バ 1 5 — 2 を通して上り光信号を送信し、 主装置の光受信回路 4 2 はその上り光信号を受信する。 図 1 6 ( b ) には、 従装置の光受信 回路 4 8 と光送信回路 4 9のヘッ ドエンド構成を示す。 図 1 6 ( b ) において、 従装置の光受信回路 4 8では、 光ファイバ 1 5— 1 を 介して受信した下り光信号は、 光受信部 4 3で検出され、 検出され た下り信号は光受信回路 4 8内で信号処理される。 一方、 上り信号 は光送信部 4 4で上り光信号に変調される。 変調された上り光信号 は光ファイノ I 5— 2を通して送信される。 上り光信号、又は下り光信号の送信と受信の動作を図 1 7 に示す。 図 1 7において、 主装置の光送信回路で、 下り信号の駆動電流によ り発光素子を駆動する (図 1 7 ( a ))。 発光素子の光出力は駆動電 流に対して、 ほぼ直線的な関係にある (図 1 7 ( b ))。 その結果、 主装置の光送信回路は下り信号の波形に近い下り光信号出力を送信 する (図 1 7 ( c ))。 従装置の光受信回路では、 光受信回路入力の 信号成分に対して閾値を設定して、 下り信号を検出する (図 1 7 ( d ))。 従装置の光送信回路と主装置の光受信回路の動作も同様で ある。 即ち、 主装置の光送信回路と従装置の光送信回路はそれぞれ 発光素子を持つ必要がある。 The configuration of the bidirectional transmission method between the master device and the slave device is described with reference to Fig. 16 (a). Figure 16 shows a bidirectional optical transmission system in which bidirectional transmission is performed between a master device and a slave device using a two-core optical fiber. That is, as shown in FIG. 16 (a), between the optical transmission circuit 41 of the main device and the optical reception circuit 48 of the slave device, and between the optical transmission circuit 49 of the slave device and the optical reception circuit of the master device. 4 and 2 are connected by two-core optical fibers 15 _ 1 and 15 _ 2 to perform bidirectional transmission. In FIG. 16 (a), the optical transmission circuit 41 of the main unit transmits a downstream optical signal through the optical fiber 15-1, and the optical reception circuit 48 of the slave unit receives the downstream optical signal. The optical transmission circuit 49 of the slave device transmits an upstream optical signal through the optical fiber 15-2, and the optical reception circuit 42 of the master device receives the upstream optical signal. FIG. 16 (b) shows a head-end configuration of the optical receiving circuit 48 and the optical transmitting circuit 49 of the slave device. In FIG. 16 (b), in the optical receiver circuit 48 of the slave device, the downstream optical signal received via the optical fiber 15-1 is detected by the optical receiver 43, and the detected downstream signal is transmitted to the optical receiver 43. The signal is processed in the receiving circuit 48. On the other hand, the upstream signal is modulated into an upstream optical signal by the optical transmitter 44. The modulated upstream optical signal is transmitted through the optical finos I5-2. The operation of transmitting and receiving an upstream optical signal or downstream optical signal is shown in FIG. In FIG. 17, the light-emitting element is driven by the drive current of the downstream signal in the optical transmission circuit of the main device (FIG. 17 (a)). The light output of the light-emitting element is almost linearly related to the drive current (Fig. 17 (b)). As a result, the optical transmission circuit of the main unit transmits the downstream optical signal output close to the waveform of the downstream signal (Fig. 17 (c)). In the optical receiver circuit of the slave device, a threshold is set for the signal component input to the optical receiver circuit, and a downstream signal is detected (Fig. 17 (d)). The same applies to the operation of the optical transmission circuit of the slave device and the operation of the optical reception circuit of the master device. That is, the optical transmission circuit of the master device and the optical transmission circuit of the slave device must each have a light emitting element.
従来の他の双方向伝送方式の構成を図 1 8に示す。 本構成は、 主 装置と複数の従装置で 2芯光ファイバ双方向 · 波長多重マルチボイ ント伝送する双方向光伝送方式である。 図 1 8 において、 4 1 — 1 〜4 1 — Nは主装置の光送信回路、 4 2 — 1〜 4 2 — Nは主装置の 光受信回路、 4 5 — 1、 4 5 _ 2は主装置の波長多重回路、 1 5 — 1、 1 5 — 2は光ファイバ、 1 6 — 1、 1 6— 2は光ファイバの途 中に設けられた波長多重回路、 4 8 — :! 〜 4 8 — Nは従装置の光受 信回路、 4 9 一 :!〜 4 9— Nは従装置の光送信回路である。 ここで は、 2以上の複数を表すときに記号 Nを用いた。 例えば、 光送信回 路 4 1 一 ;!〜 4 1 — Nは 2以上の複数の光送信回路を表す。  Fig. 18 shows the configuration of another conventional bidirectional transmission system. This configuration is a bidirectional optical transmission system in which a two-core optical fiber bidirectional / wavelength-division multiplexed multipoint transmission is performed between a main device and a plurality of slave devices. In Fig. 18, 4 1 — 1 to 4 1 — N is the optical transmission circuit of the main unit, 4 2 — 1 to 4 2 — N is the optical receiving circuit of the main unit, 4 5 — 1 and 4 5 _ 2 are the main unit. 15-1 and 15-2 are optical fibers, 16-1 and 16-2 are wavelength multiplex circuits provided in the middle of the optical fiber, and 48-8 :! ~ 48 — N is the optical receiving circuit of the slave, 49 1:! 449-N is the optical transmission circuit of the slave device. Here, the symbol N is used to represent two or more. For example, optical transmission circuit 4 1 1; 44 1 —N represents two or more optical transmission circuits.
主装置と複数の従装置で双方向伝送する方式の構成について説明 する。 図 1 8 において、 主装置の複数の光送信回路 4 1 — 1〜4 1 一 Nは下り信号で変調したそれぞれの下り光信号をそれぞれ予め割 り当てられた波長 ( A 1 λ 2、 · · λ Ν) で主装置の波長多重回路 4 5 - 1 に向けて送信する。 波長多重回路 4 5 — 1 は、 複数の光送 信回路から送信された、 異なる波長の下り光信号を光ファイバ 1 5 一 1 に波長多重する。 光ファイバ 1 5— 1の途中に設けられた波長 多重回路 1 6 — 1 は、 それぞれの下り光信号を波長に応じてそれぞ れの従装置に向けて波長分離する。 それぞれの従装置の光受信回路 4 8 — 1〜 4 8 — Nは光ファイバ 1 5 — 1 を通して受信した下り光 信号から信号成分を検出する。 一方、 それぞれの従装置の光送信回 路 4 9 - 1 〜 4 9 一 Nは上り信号で変調した上り光信号を光フアイ バ 1 5 — 2 に送信する。 光ファイバ 1 5 — 2の途中に設けられた波 長多重回路 1 6 — 2は複数の光送信回路 4 9 — :! 〜 4 9 — Nから送 信された、 それぞれ予め割り当てられた波長 ( A i、 λ 2、 · · λ Ν ) の上り光信号を主装置に向けて波長多重する。 主装置の波長多重 回路 4 5 - 2は複数の従装置の光送信回路 4 9 - 1 〜 4 9 — Νから 送信された、 それぞれ予め割り当てられた波長 ( λ ;^ λ 2、 · · λ Ν) の上り光信号を波長毎に主装置の光受信回路 4 2 — 1〜 4 2 _ Νに向けて波長分離する。 主装置の複数の光受信回路 4 2 — 1 〜 4 2 - Νは、 それぞれ受信した上り光信号から上り信号を検出する。 ここで、 従装置の光送信回路 4 9 _ 1 〜 4 9 _ Νはそれぞれ、 所 定の波長の上り光信号を送信しなければならない。 それぞれの従装 置の光送信回路 4 9 一 :!〜 4 9 _ Νはそれぞれ発光素子を持つ必要 があり、 さ らに、 これらの発光素子の波長を高精度に制御したり、 維持したりする必要がある。 従装置は一般にそれぞれ異なる場所に 分散配置されるため、 環境温度等が異なる。 環境温度の変化により 発光素子の波長が所定の値から変移すると、 光ファイバ 1 5 — 2 の 途中にある波長多重回路 1 6 — 2や、 主装置の波長多重回路 4 5 — 2において、 光損失が増大する。 さらに、 変移が大きい場合は伝送 ができなくなる虞があった。 The configuration of a system for performing bidirectional transmission between a main device and a plurality of slave devices will be described. In FIG. 18, a plurality of optical transmission circuits 4 1-1 to 4 1 1 N of the main unit transmit wavelengths (A 1 λ 2 ,...) Assigned to respective downstream optical signals modulated by the downstream signals. At λ)), the signal is transmitted to the wavelength multiplexing circuit 45-1 of the main device. The wavelength division multiplexing circuit 45-1 multiplexes downstream optical signals of different wavelengths transmitted from a plurality of optical transmission circuits onto the optical fiber 115-1. The wavelength multiplexing circuit 16-1 provided in the middle of the optical fiber 15-1 separates each downstream optical signal toward each slave device according to the wavelength. Optical receiving circuit of each slave device 4 8 — 1 to 4 8 — N detect signal components from the downstream optical signal received through the optical fiber 15-1. On the other hand, the optical transmission circuits 49-1 to 49-1 N of the respective slave devices transmit the upstream optical signals modulated by the upstream signals to the optical fibers 15-2. A wavelength multiplexing circuit 16-2 provided in the middle of the optical fiber 15-2 is a plurality of optical transmitting circuits 49-:! ~ 49-N, each of which has a wavelength (A i, λ 2 , ... λ)) are wavelength-multiplexed toward the main unit. The wavelength multiplexing circuit 45-2 of the master device is a pre-assigned wavelength (λ; ^ λ 2 , · · λ た) transmitted from the optical transmission circuits 49-1 to 49-の of the slave devices. ) Is wavelength-separated for each wavelength toward the optical receiver circuit 42-1 to 42_Ν of the main device. Each of the plurality of optical receiving circuits 42-1 to 42-の of the main device detects an upstream signal from the received upstream optical signal. Here, each of the optical transmission circuits 49_1 to 49_Ν of the slave device must transmit an upstream optical signal of a predetermined wavelength. Optical transmission circuit of each slave device 49 1 ~ 49_Ν must each have a light emitting element, and furthermore, it is necessary to control or maintain the wavelength of these light emitting elements with high precision. Slave devices are generally distributed at different locations, and therefore have different environmental temperatures. When the wavelength of the light-emitting element shifts from a predetermined value due to a change in environmental temperature, light loss occurs in the wavelength multiplexing circuit 16-2 in the optical fiber 15-2 and the wavelength multiplexing circuit 45-2 in the main unit. Increase. Furthermore, if the transition is large, transmission may not be possible.
本発明は、 このような問題を解決するために、 従装置の光送信回 路で発光素子を不要とし、 また、 従装置の光送信回路で発光素子の 波長を高精度に制御したり、 維持したりすることを不要とすること を目的とする。  In order to solve such a problem, the present invention eliminates the need for a light emitting element in the optical transmission circuit of the slave device, and controls or maintains the wavelength of the light emitting element with high accuracy in the optical transmission circuit of the slave device. The purpose is to make it unnecessary.
なお、 光信号を処理する光部品として、 従来は、 半導体光増幅回 路 (例えば、 T.Mukai and T. Saitoh, "5.2dB noise figure in a 1.5um InGaAsP traveling wave laser amplifier", Electron. Let t. , Vol.23, No, 5, pp .216- 218(1987) ) がある。 これは、 入力光信号 と出力光信号の波形がリニア一な関係となる半導体光増幅回路であ る。 発明の開示 Conventionally, semiconductor optical amplifier circuits (eg, T. Mukai and T. Saitoh, “5.2 dB noise figure in a 1.5 μm InGaAsP traveling wave laser amplifier”, Electron. t., Vol.23, No.5, pp.216-218 (1987)). This is a semiconductor optical amplifier circuit in which the waveforms of the input optical signal and the output optical signal have a linear relationship. Disclosure of the invention
前述した目的を達成するために、 本願第一の発明は、 主装置と従 装置との間を第一の光ファイバと第二の光ファイバで 2芯光フアイ バ双方向伝送する双方向光伝送方式であって、 前記主装置は、 下り 信号で変調した信号成分にバイアス成分を重畳した下り光信号を前 記第一の光ファイバに向けて送信する光送信回路と、 前記第二の光 ファイバを通して受信した上り光信号から上り信号を検出する光受 信回路とを備え、 前記従装置は、 前記第一の光ファイバを通して受 信した前記下り光信号から前記信号成分を検出する光受信回路と、 前記受信した下り光信号の一部を飽和増幅 · 減衰回路によって前記 上り信号で変調した前記上り光信号を前記第二の光ファイバに向け て送信する光送信回路とを備えることを特徴とする双方向光伝送方 式でめる。  In order to achieve the above-mentioned object, the first invention of the present application is a bidirectional optical transmission system in which a two-core optical fiber is bidirectionally transmitted between a master device and a slave device using a first optical fiber and a second optical fiber. An optical transmission circuit for transmitting, to the first optical fiber, a downstream optical signal in which a bias component is superimposed on a signal component modulated by a downstream signal, and the second optical fiber; An optical receiving circuit for detecting an upstream signal from an upstream optical signal received through the optical fiber, wherein the slave device detects the signal component from the downstream optical signal received through the first optical fiber; and An optical transmission circuit for transmitting the upstream optical signal, which is obtained by modulating a part of the received downstream optical signal with the upstream signal by a saturation amplification / attenuation circuit, to the second optical fiber, Two-way light transmission Square Mel by formula.
本願第二の発明は、 主装置と従装置との間を 1芯の光ファイバで 方向多重双方向伝送する双方向光伝送方式であって、 前記主装置は 、 下り信号で変調した信号成分にバイアス成分を重畳した下り光信 号を前記光ファイバに向けて送信する光送信回路と、 前記光フアイ バを通して受信した上り光信号から上り信号を検出する光受信回路 とを備え、 前記従装置は、 前記光ファイバを通して受信した前記下 り光信号から前記信号成分を検出する光受信回路と、 前記受信した 下り光信号の一部を飽和増幅 · 減衰回路によって前記上り信号で変 調した前記上り光信号を前記光ファイバに向けて送信する光送信回 路とを備えることを特徵とする双方向光伝送方式である。  The second invention of the present application is a bidirectional optical transmission system for performing directional multiplex bidirectional transmission between a master device and a slave device using a single-core optical fiber, wherein the master device converts a signal component modulated by a downstream signal into a signal component. An optical transmission circuit for transmitting a downstream optical signal having a bias component superimposed thereon toward the optical fiber; and an optical receiving circuit for detecting an upstream signal from an upstream optical signal received through the optical fiber. An optical receiving circuit for detecting the signal component from the downstream optical signal received through the optical fiber; and an upstream optical signal obtained by modulating a part of the received downstream optical signal with the upstream signal by a saturation amplification / attenuation circuit. And a light transmission circuit for transmitting the light toward the optical fiber.
本願第三の発明は、 本願第二の発明である主装置と従装置との間 を 1芯の光ファイバで方向多重双方向伝送する双方向光伝送方式に おいて、 前記飽和増幅 · 減衰回路が、 半導体光増幅器であって、 前 記下り光信号の入射端面と対向する端面に劈開状態に比べて高反射 率を有する膜をコーティ ングし、 前記下り光信号の入射端面から送 出する反射型構成であることを特徴とする双方向光伝送方式である 本願第四の発明は、 主装置と複数の従装置との間を第一の光ファ ィバと第二の光ファイバで 2芯光ファイバ双方向 · 波長多重マルチ ポイント伝送する双方向光伝送方式であって、 前記主装置は、 下り 信号で変調した信号成分にバイアス成分を重畳したそれぞれの下り 光信号を前記第一の光ファイバに向けて送信する複数の光送信回路 と、 前記第二の光ファイバを通して受信したそれぞれの上り光信号 から上り信号を検出する複数の光受信回路とを備え、 前記複数の従 装置は、 それぞれ、 前記第一の光ファイバを通して受信した前記下 り光信号から前記信号成分を検出する光受信回路と、 それぞれ、 前 記受信した下り光信号の一部を飽和増幅 · 減衰回路によって前記上 り信号で変調した前記上り光信号を前記第二の光ファイバに向けて 送信する光送信回路とを備えることを特徴とする双方向光伝送方式 である。 The third invention of the present application is a two-way optical transmission system in which the main device and the slave device are two-way multiplexed bidirectionally transmitted by a single optical fiber between the master device and the slave device. Wherein the saturation amplification / attenuation circuit is a semiconductor optical amplifier, and a film having a higher reflectivity than a cleavage state is coated on an end surface facing the incident end surface of the down optical signal, The fourth invention of the present application, which is a bidirectional optical transmission system characterized by a reflection type configuration in which a signal is transmitted from an incident end face of a signal, comprises a first optical fiber between a master device and a plurality of slave devices. A two-core optical fiber bi-directional wavelength-division multiplexing multi-point transmission using a second optical fiber and a second optical fiber, wherein the main unit is configured to superimpose a bias component on a signal component modulated by a downlink signal. A plurality of optical transmission circuits for transmitting an optical signal toward the first optical fiber; anda plurality of optical reception circuits for detecting an upstream signal from each upstream optical signal received through the second optical fiber, The compound Each of the slave units includes: an optical receiving circuit that detects the signal component from the downstream optical signal received through the first optical fiber; and a saturation amplification / attenuation unit that partially amplifies the received downstream optical signal. An optical transmission circuit for transmitting the upstream optical signal modulated by the upstream signal to the second optical fiber by a circuit.
本願第五の発明は、 主装置と複数の従装置を 1芯の光ファイバで 方向多重双方向 · 波長多重マルチポイント伝送する双方向光伝送方 式であって、 前記主装置は、 下り信号で変調した信号成分にバイァ ス成分を重畳したそれぞれの下り光信号を前記光ファイバに向けて 送信する複数の光送信回路と、 前記光ファイバを通して受信したそ れぞれの上り光信号から上り信号を検出する複数の光受信回路とを 備え、 前記複数の従装置は、 それぞれ、 前記光ファイバを通して受 信した前記下り光信号から前記信号成分を検出する光受信回路と、 それぞれ、 前記受信した下り光信号の一部を飽和増幅 , 減衰回路に よって前記上り信号で変調した前記上り光信号を前記光ファイバに 向けて送信する光送信回路とを備えることを特徴とする双方向光伝 送方式である。 A fifth invention of the present application is a bidirectional optical transmission system in which a main device and a plurality of slave devices are transmitted in a single-core optical fiber in a multiplexed bidirectional / wavelength multiplexed multipoint manner, wherein the main device is a downstream signal. A plurality of optical transmission circuits for transmitting, to the optical fiber, respective downstream optical signals in which a bias component is superimposed on a modulated signal component; and an upstream signal from each upstream optical signal received through the optical fiber. A plurality of optical receiving circuits for detecting, the plurality of slave devices each comprising: an optical receiving circuit for detecting the signal component from the downstream optical signal received through the optical fiber; and An optical transmission circuit for transmitting, toward the optical fiber, the upstream optical signal obtained by modulating a part of the signal with the upstream signal by a saturation amplification / attenuation circuit. Optical transmission This is the transmission method.
本願第六の発明は、 本願第五の発明である主装置と複数の従装置 を 1芯の光ファイバで方向多重双方向一波長多重マルチポイント伝 送する双方向光伝送方式において、 前記飽和増幅 · 減衰回路が、 半 導体光増幅器であって、 前記下り光信号の入射端面と対向する端面 に劈開状態に比べて高反射率を有する膜をコーティ ングし、 前記下 り光信号の入射端面から送出する反射型構成であることを特徴とす る双方向光伝送方式である。  The sixth invention of the present application is the bidirectional optical transmission system according to the fifth invention, in which a master device and a plurality of slave devices are transmitted in a direction-multiplexed bidirectional one-wavelength multiplex multipoint manner using a single optical fiber. An attenuating circuit, which is a semiconductor optical amplifier, which coats a film having a higher reflectivity than a cleavage state on an end surface facing the incident end surface of the downstream optical signal, from the incident end surface of the downstream optical signal; This is a bidirectional optical transmission system characterized by a reflection type configuration for transmission.
本願第七の発明は、 主装置と複数の従装置との間を第一の光ファ ィバと第二の光ファイバで 2芯光ファイバ双方向 · 波長時分割多重 マルチポイント伝送する双方向光伝送方式であって、 前記主装置は 、 下り信号で変調した信号成分にバイアス成分を重畳したそれぞれ の下り光信号を従装置毎の波長と時間領域に分離して前記第一の光 ファイバに向けて送信する光送信回路と、 前記第二の光ファイバを 通して受信したそれぞれの上り光信号から上り信号を検出する少な く とも 1の光受信回路とを備え、 前記複数の従装置は、 それぞれ、 前記第一の光ファイバを通して受信した前記下り光信号から前記信 号成分を検出する光受信回路と、 それぞれ、 前記受信した下り光信 号の一部を飽和増幅 · 減衰回路によって前記上り信号で変調した前 記上り光信号を前記第二の光ファイバに向けて送信する光送信回路 とを備えることを特徴とする双方向光伝送方式である。  A seventh invention of the present application is directed to a bidirectional optical fiber bidirectional / wavelength-time-division multiplexed bidirectional transmission between a master device and a plurality of slave devices using a first optical fiber and a second optical fiber. In the transmission method, the master device separates each downstream optical signal obtained by superimposing a bias component on a signal component modulated by a downstream signal into a wavelength and a time domain for each slave device and directs the separated downstream optical signal to the first optical fiber. An optical transmission circuit for transmitting an optical signal, and at least one optical receiving circuit for detecting an upstream signal from each of the upstream optical signals received through the second optical fiber. An optical receiving circuit that detects the signal component from the downstream optical signal received through the first optical fiber; anda part of the received downstream optical signal is modulated with the upstream signal by a saturation amplification / attenuation circuit. I An optical transmission circuit for transmitting the upstream optical signal to the second optical fiber.
本願第八の発明は、 本願第七の発明である主装置と複数の従装置 との間を第一の光ファイバと第二の光ファイバで 2芯光ファイバ双 方向 · 波長時分割多重マルチボイント伝送する双方向光伝送方式に おいて、 前記光送信回路に光出力の波長を従装置毎の波長に可変で きる波長可変光源を用いたことを特徴とする双方向光伝送方式であ る。  The eighth invention of the present application is a two-core optical fiber bidirectional / wavelength time-division multiplexing multi-point optical system using a first optical fiber and a second optical fiber between a master device and a plurality of slave devices according to the seventh invention of the present application. In the bidirectional optical transmission system for transmission, a wavelength tunable light source capable of changing the wavelength of an optical output to the wavelength of each slave device is used for the optical transmission circuit.
本願第九の発明は、 主装置と複数の従装置を 1芯の光ファイバで 方向多重双方向 · 波長時分割多重マルチボイント伝送する双方向光 伝送方式であって、 前記主装置は、 下り信号で変調した信号成分に バイアス成分を重畳したそれぞれの下り光信号を従装置毎の波長と 時間領域に分離して前記光ファイバに向けて送信する光送信回路と 、 前記光ファイバを通して受信したそれぞれの上り光信号から上り 信号を検出する少なく とも 1 の光受信回路とを備え、 前記複数の従 装置は、 それぞれ、 前記光ファイバを通して受信した前記下り光信 号から前記信号成分を検出する光受信回路と、 それぞれ、 前記受信 した下り光信号の一部を飽和増幅 · 減衰回路によって前記上り信号 で変調した前記上り光信号を前記光ファイバに向けて送信する光送 信回路とを備えることを特徴とする双方向光伝送方式である。 The ninth invention of the present application is directed to a bidirectional optical system in which a main unit and a plurality of slave units are transmitted in a single-core optical fiber in a direction-division multiplexed / wavelength time division multiplexed multipoint transmission. In the transmission method, the master device separates each downstream optical signal obtained by superimposing a bias component on a signal component modulated by a downstream signal into a wavelength and a time domain for each slave device and transmits the separated optical signal to the optical fiber. An optical transmitting circuit, and at least one optical receiving circuit that detects an upstream signal from each upstream optical signal received through the optical fiber, wherein the plurality of slave devices each receive the downstream signal received through the optical fiber. An optical receiving circuit for detecting the signal component from the optical signal; and transmitting the upstream optical signal, which is obtained by modulating a part of the received downstream optical signal with the upstream signal by a saturation amplification / attenuation circuit, toward the optical fiber. A bidirectional optical transmission system characterized by comprising an optical transmission circuit.
本願第十の発明は、 本願第九の発明である主装置と複数の従装置 を 1芯の光ファイバで方向多重双方向 · 波長時分割多重マルチボイ ン 卜伝送する双方向光伝送方式において、 前記飽和増幅 · 減衰回路 が、 半導体光増幅器であって、 前記下り光信号の入射端面と対向す る端面に劈開状態に比べて高反射率を有する膜をコーティ ングし、 前記下り光信号の入射端面から送出する反射型構成であることを特 徵とする双方向光伝送方式である。  A tenth invention of the present application is the ninth invention of the present application, wherein the main device and the plurality of slave devices are transmitted in a single-core optical fiber in a directional multiplex bidirectional / wavelength time division multiplex multipoint transmission system. A saturating amplification / attenuation circuit, which is a semiconductor optical amplifier, wherein a coating having a higher reflectivity than a cleavage state is coated on an end face opposed to an incident end face of the downstream optical signal; This is a bidirectional optical transmission system that is characterized by a reflection-type configuration for transmission from an optical network.
本願第十一の発明は、 本願第九の発明である主装置と複数の従装 置を 1芯の光ファイバで方向多重双方向 · 波長時分割多重マルチポ イント伝送する双方向光伝送方式において、 前記光送信回路に光出 力の波長を従装置毎の波長に可変できる波長可変光源を用いたこと を特徴とする双方向光伝送方式である。  An eleventh invention of the present application relates to a ninth invention of the present invention, which relates to a bidirectional optical transmission system in which a main device and a plurality of slave devices are transmitted in a direction multiplexed bidirectional / wavelength time division multiplexed multipoint using a single optical fiber. A bidirectional optical transmission system, characterized in that a wavelength-variable light source capable of changing a wavelength of an optical output to a wavelength of each slave device is used for the optical transmission circuit.
本願第十二の発明は、 受信した第一の光信号の一部を飽和増幅 · 減衰回路によって第二の送信信号で変調した第二の光信号を光ファ ィバに向けて送信する光送信回路を備える光送受信装置に対して、 第一の送信信号で変調した信号成分にバイアス成分を重畳した第一 の光信号を送信する光送信回路と、 光ファイバを通して受信した前 記第二の光信号から信号成分を検出する光受信回路とを備える光送 受信装置である。 本願第十三の発明は、 信号で変調した信号成分にバイアス成分を 重畳した光信号を、 光ファイバを通して受信する光受信回路と、 前 記受信した光信号の一部を飽和増幅 · 減衰回路によって送信する信 号で変調して光ファイバに向けて送信する光送信回路とを備える光 送受信装置である。 A twelfth invention of the present application is directed to an optical transmission system for transmitting a second optical signal, which is obtained by modulating a part of a received first optical signal with a second transmission signal by a saturation amplification / attenuation circuit, to an optical fiber. An optical transmission circuit for transmitting a first optical signal in which a bias component is superimposed on a signal component modulated by a first transmission signal to an optical transmitting and receiving apparatus having a circuit; and the second optical signal received through an optical fiber. An optical transmitting and receiving apparatus comprising: an optical receiving circuit that detects a signal component from a signal. A thirteenth invention of the present application is directed to an optical receiving circuit for receiving an optical signal obtained by superimposing a bias component on a signal component modulated by a signal through an optical fiber, and a part of the optical signal received by a saturation amplification / attenuation circuit. An optical transmitting and receiving apparatus comprising: an optical transmitting circuit that modulates a signal to be transmitted and transmits the modulated signal to an optical fiber.
本願第十四の発明は、 本願第十二の発明である光送受信装置にお いて、 前記バイアス成分が前記信号成分の 5 0 %以上、 好ましくは 1 0 0 %以上であることを特徵とする光送受信装置である。  The fourteenth invention of the present application is the optical transmission / reception device according to the twelfth invention, wherein the bias component is at least 50%, preferably at least 100% of the signal component. An optical transceiver.
本願第十五の発明は、 本願第十三の発明である光送受信装置にお いて、 前記飽和増幅 · 減衰回路が、 制御電流によって増幅度を制御 する増幅部と送信する信号によって光信号を変調する変調部とを有 する半導体光増幅器であることを特徴とする光送受信装置である。  The fifteenth invention of the present application is the optical transmission / reception device according to the thirteenth invention of the present application, wherein the saturation amplification / attenuation circuit modulates an optical signal with an amplification unit that controls an amplification degree by a control current and a signal to be transmitted. An optical transmitting and receiving apparatus characterized by being a semiconductor optical amplifier having a modulating unit for performing the operation.
本願第十六の発明は、 本願第十三の発明である光送受信装置にお いて、 前記飽和増幅 · 減衰回路が、 制御電流によって飽和させる増 幅部と送信する信号によって光信号を吸収する変調部とを有する半 導体光素子であることを特徴とする光送受信装置である。  The sixteenth invention of the present application is the optical transmission / reception device according to the thirteenth invention of the present application, wherein the saturation amplification / attenuation circuit includes an amplification unit that saturates with a control current and a modulation that absorbs an optical signal with a signal to be transmitted. And a semiconductor optical element having a portion.
なお、 これらの各構成は、 可能な限り組み合わせることができる ここで、 飽和増幅 · 減衰回路は、 光入力が小さい範囲では線形増 幅するが、 光入力が大きくなると増幅度は飽和し、 光入力レベルに 関わらず光出力が一定となる回路である。 さらに、 増幅度が制御可 能であり、 増幅度を高く して飽和型増幅させたり、 逆に増幅度を抑 えて減衰させたりすることができる。 なお、 飽和増幅 · 減衰回路で の減衰には単に増幅度を小さく したものも含まれる。  Note that these configurations can be combined as much as possible.Here, the saturation amplification / attenuation circuit linearly amplifies in the range where the optical input is small. This is a circuit where the light output is constant regardless of the level. Further, the amplification degree is controllable, so that the amplification degree can be increased to perform saturation amplification, or conversely, the amplification degree can be suppressed and attenuated. Note that the attenuation in the saturation amplification / attenuation circuit includes that in which the degree of amplification is simply reduced.
2芯光ファイバ双方向伝送とは、 下り光信号の伝送に第一の光フ アイバを、 上り光信号の伝送に第二の光ファイバを使用して双方向 伝送する技術をいう。 1芯光ファイバ方向多重双方向伝送とは、 下 り光信号と上り光信号の伝送に同じ光ファイバを使用し、 同じ波長 を有する下り光信号と上り光信号の合流、 分岐に光合分岐回路を利 用して双方向伝送する技術をいう。 Two-core optical fiber bidirectional transmission refers to a technology for bidirectional transmission using a first optical fiber for transmitting downstream optical signals and a second optical fiber for transmitting upstream optical signals. Single-core optical fiber direction multiplex bidirectional transmission means that the same optical fiber is used for transmission of downstream optical signals and upstream optical signals, and an optical multiplexing / branching circuit is used to join and branch downstream optical signals and upstream optical signals having the same wavelength. Profit Is a technology for bi-directional transmission.
2芯光ファイバ双方向 · 波長多重マルチポイント伝送とは、 主装 置と複数の従装置を 1対 Nのマルチポイント接続した伝送方式にお いて、 下り光信号の伝送に第一の光ファイバを、 上り光信号の伝送 に第二の光ファイバを使用し、 上り光信号と下り光信号にそれぞれ 従装置ごとに異なる波長を割り当てて、 主装置と光ファイバの途中 に設けられた波長多重回路の間を波長多重伝送して双方向伝送する 技術をいう。 1芯光ファイバ方向多重双方向 · 波長多重マルチボイ ント伝送とは、 主装置と複数の従装置を 1対 Nのマルチポイント接 続した伝送方式において、 下り光信号の伝送と上り光信号の伝送に 同じ光ファイバを使用し、 上り光信号と下り光信号は同じ波長で、 かつ従装置ごとに異なる波長を割り当てて、 主装置と光ファイバの 途中に設けられた波長多重回路の間を波長多重伝送して双方向伝送 する技術をいう。  Two-core optical fiber bidirectionalWavelength multiplexing multipoint transmission refers to a transmission method in which a main unit and a plurality of slave units are connected in a 1-to-N multipoint connection, and the first optical fiber is used to transmit downstream optical signals. The second optical fiber is used for transmission of the upstream optical signal, and different wavelengths are assigned to the upstream optical signal and the downstream optical signal for each slave device. This is a technology to perform bidirectional transmission by wavelength multiplex transmission between them. Single-core optical fiber direction multiplexing bidirectional / wavelength multiplexing multipoint transmission refers to the transmission of downstream optical signals and the transmission of upstream optical signals in a transmission system in which a main unit and a plurality of slave units are connected in a 1: N multipoint connection. The same optical fiber is used, the upstream optical signal and the downstream optical signal have the same wavelength, and different wavelengths are assigned to each slave device, and wavelength multiplex transmission is performed between the main device and the wavelength multiplexing circuit provided in the optical fiber. This is a technology for bidirectional transmission.
2芯光ファイバ双方向 · 波長時分割多重マルチポイン ト伝送とは 、 主装置と複数の従装置を 1対 Nのマルチポイント接続した伝送方 式において、 下り光信号の伝送に第一の光ファイバを、 上り光信号 の伝送に第二の光ファイバを使用し、 上り光信号と下り光信号にそ れぞれ従装置ごとに異なる波長と時間領域を割り当てて、 主装置と 光ファイバの途中に設けられた波長多重回路の間を波長多重伝送し て双方向伝送する技術をいう。 1芯光ファイバ方向多重双方向 · 波 長時分割多重マルチポイント伝送とは、 主装置と複数の従装置を 1 対 Nのマルチポイント接続した伝送方式において、 下り光信号の伝 送と上り光信号の伝送に同じ光ファイバを使用し、 上り光信号と下 り光信号は同じ波長で、 かつ従装置ごとに異なる波長と時間領域を 割り当てて、 主装置と光ファイバの途中に設けられた波長多重回路 の間を波長多重伝送して双方向伝送する技術をいう。  Two-way optical fiber bi-directional wavelength-division multiplexing multipoint transmission is a transmission method in which a master unit and a plurality of slave units are connected in a 1: N multipoint connection. The second optical fiber is used for transmission of the upstream optical signal, and a different wavelength and time domain are assigned to each of the slave optical devices for the upstream optical signal and the downstream optical signal. This is a technology that performs wavelength multiplex transmission between provided wavelength multiplexing circuits and bidirectional transmission. Single-core optical fiber direction multiplexing bidirectional · Wavelength time division multiplexing multipoint transmission refers to the transmission of downstream optical signals and upstream optical signals in a transmission system in which a master unit and multiple slave units are connected in a 1: N multipoint connection. The same optical fiber is used for transmission, the upstream optical signal and the downstream optical signal have the same wavelength, and a different wavelength and time domain are assigned to each slave device. This is a technology for bidirectional transmission by wavelength multiplex transmission between circuits.
また、 ここでは、 下りとは、 主装置から従装置への信号の流れを いい、 上り とは、 従装置から主装置への信号の流れをいう。 図面の簡単な説明 Here, the term “down” refers to a signal flow from the master device to the slave device, and the term “up” refers to a signal flow from the slave device to the master device. BRIEF DESCRIPTION OF THE FIGURES
図 1 は、 本願発明の実施形態を示す双方向光伝送方式の構成図で ある。  FIG. 1 is a configuration diagram of a bidirectional optical transmission system showing an embodiment of the present invention.
図 2は、 本願発明の双方向光伝送方式の動作図である。  FIG. 2 is an operation diagram of the bidirectional optical transmission system of the present invention.
図 3は、 本願発明の双方向光伝送方式の動作図である。  FIG. 3 is an operation diagram of the bidirectional optical transmission system of the present invention.
図 4は、 本願発明の実施形態を示す双方向光伝送方式の構成図で ある。  FIG. 4 is a configuration diagram of a bidirectional optical transmission system showing an embodiment of the present invention.
図 5は、 本願発明の実施形態を示す双方向光伝送方式の構成図で ある。  FIG. 5 is a configuration diagram of a bidirectional optical transmission system showing an embodiment of the present invention.
図 6は、 本願発明の実施形態を示す双方向光伝送方式の構成図で ある。  FIG. 6 is a configuration diagram of a bidirectional optical transmission system showing an embodiment of the present invention.
図 7は、 本願発明の実施形態を示す双方向光伝送方式の構成図で ある。  FIG. 7 is a configuration diagram of a bidirectional optical transmission system showing an embodiment of the present invention.
図 8は、 本願発明の実施形態を示す出力強度飽和型増幅変調器の 概略構造図である。  FIG. 8 is a schematic structural diagram of an output intensity saturated amplification modulator according to an embodiment of the present invention.
図 9は、 本願発明の実施形態を示す出力強度飽和型増幅変調器の 概略構造図である。  FIG. 9 is a schematic structural diagram of an output intensity saturated amplification modulator showing an embodiment of the present invention.
図 1 0は、 本願発明の実施形態を示す反射膜付き出力強度飽和型 増幅変調器の概略断面図である。  FIG. 10 is a schematic sectional view of an output-intensity-saturated amplification modulator with a reflective film according to an embodiment of the present invention.
図 1 1は、 本願発明の実施形態を示す反射膜付き出力強度飽和型 増幅変調器の概略断面図である。  FIG. 11 is a schematic sectional view of an output-intensity-saturated amplification modulator with a reflective film according to an embodiment of the present invention.
図 1 2は、 反射膜付き出力強度飽和型増幅変調器を備える光送受 信装置の構成図である。  FIG. 12 is a configuration diagram of an optical transmitting and receiving apparatus including an output intensity saturated amplification modulator with a reflection film.
図 1 3は、 本願発明の実施形態を示す出力強度飽和型増幅変調器 の概略構造図である。  FIG. 13 is a schematic structural diagram of an output intensity saturated amplification modulator showing an embodiment of the present invention.
図 1 4は、 本願発明の実施形態を示す双方向光伝送方式の構成図 である。  FIG. 14 is a configuration diagram of a bidirectional optical transmission system showing an embodiment of the present invention.
図 1 5は、 本願発明の実施形態を示す双方向光伝送方式の構成図 である。 FIG. 15 is a configuration diagram of a bidirectional optical transmission system showing an embodiment of the present invention. It is.
図 1 6は 従来の双方向光伝送方式の構成図である  Figure 16 is a block diagram of a conventional bidirectional optical transmission system.
図 1 7は 従来の双方向光伝送方式の動作図である  Figure 17 is an operation diagram of the conventional bidirectional optical transmission system.
図 1 8は 従来の双方向光伝送方式の構成図である 図中の符号の説明は次の通りである。 1 1、 1 1 — 1 、 1 1 一 2、 1 1 一 Nは主装置の光送信回路、 1 2、 1 2 — 1、 1 2 — 2、 1 2 一 Nは主装置の光受信回路、 1 3、 1 3 — 1、 1 3 _ 2は主装置の 波長多重回路、 1 4、 1 4— 1、 1 4 - 2 , 1 4一 Nは主装置の光 合分岐回路、 1 5、 1 5 — 1、 1 5 — 2は光ファイバ、 1 6、 1 6 一 1、 1 6 — 2は波長多重回路、 1 7、 1 7 — 1、 1 7— 2、 1 7 一 Nは従装置の光合分岐回路、 1 8、 1 8 — 1、 1 8 — 2、 1 8 - Nは従装置の光受信回路、 1 9、 1 9 — 1 、 1 9 — 2、 1 9 一 Nは 従装置の光送信回路、 2 1 は光分岐回路、 2 2は光受信部、 2 3は 駆動部、 2 4は出力強度飽和型増幅変調器、 2 5は主装置の光送信 回路、 2 6は主装置の光受信回路、 3 1 は出力強度飽和型増幅変調 器、 3 2は出力強度飽和型増幅変調器、 3 3は増幅変調部、  FIG. 18 is a configuration diagram of a conventional bidirectional optical transmission system. The description of reference numerals in the figure is as follows. 1 1, 1 1 — 1, 1 1 1 2, 1 1 1 N is the optical transmission circuit of the main unit, 1 2, 1 2 — 1, 1 2 — 2, 1 2 1 N is the optical reception circuit of the main unit, 1 3, 1 3-1, 1 3 _ 2 are main unit wavelength multiplexing circuits, 14, 14-1, 14-2, 14 4 N are main unit optical coupling / branching circuits, 15, 1 5-1, 15-2 is an optical fiber, 16-16 is 1, 1-16 is a wavelength division multiplexing circuit, 17-17-1, 17-2, 17-1 N is a slave device Optical coupling / branching circuit, 18, 18-1, 18-2, 18 -N is the optical receiving circuit of the slave device, 19, 19-1, 19-2, 19-1 N is the slave device An optical transmission circuit, 21 is an optical branching circuit, 22 is an optical receiving unit, 23 is a driving unit, 24 is an output intensity saturated amplification modulator, 25 is an optical transmission circuit of the main unit, and 26 is a main unit. Optical receiving circuit, 3 1 is an output intensity saturated amplification modulator, 3 2 is an output intensity saturation amplification modulator, 3 3 is an amplification modulation section,
3 4は出射口、 3 5は増幅部、 3 6は変調部、 3 7は反射膜付き出 力強度飽和型増幅変調器、 3 8は反射膜付き出力強度飽和型増幅変 調器、 3 9は入出射口、 4 0は反射膜、 4 1、 4 1 - 1 , 4 1 — 2 、 4 1 — Nは主装置の光送信回路、 4 2、 4 2 — 1、 4 2 — 2、 4 2— Nは主装置の光受信回路、 4 3は光受信部、 4 4は光送信部、 4 5— 1 、 4 5— 2は主装置の波長多重回路、 4 8、 4 8 — 1、 4 8— 2、 4 8 _ Nは従装置の光受信回路、 4 9、 4 9 — 1、 4 9 - 2、 4 9 一 Nは従装置の光送信回路、 6 1 は出力強度飽和型増幅変 調器、 6 2は飽和増幅部、 6 3は変調部、 6 4は半導体活性層、 6 5は吸収変調層である。 発明を実施するための最良の形態 以下、 本発明を実施するための形態について詳細に説明するが、 本発明はこれらの形態に限定して解釈されない。 3 4 is an output port, 3 5 is an amplifying section, 3 is a modulating section, 3 7 is an output intensity saturated amplifying modulator with a reflective film, 3 8 is an output intensity saturated amplifying modulator with a reflective film, 3 9 Is the entrance / exit port, 40 is the reflective film, 41, 4 1-1, 41-2, 41-N is the optical transmission circuit of the main unit, 42, 42-1, 42-2, 4 2—N is the optical receiving circuit of the main unit, 43 is the optical receiving unit, 44 is the optical transmitting unit, 45-1, 45-2 is the wavelength multiplexing circuit of the main unit, 48, 48-1, 4 8—2, 48_N is the optical receiver circuit of the slave device, 49, 49−1, 49−2, 49−1 N is the optical transmitter circuit of the slave device, and 61 is the output intensity saturated amplifier The modulator, 62 is a saturation amplification section, 63 is a modulation section, 64 is a semiconductor active layer, and 65 is an absorption modulation layer. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described in detail, but the present invention is not construed as being limited to these embodiments.
(実施の形態 1 )  (Embodiment 1)
本実施の形態は、 2芯光ファイバ双方向伝送する双方向光伝送方 式である。 本発明の実施の形態の構成を図 1 に示す。 図 1 において 、 1 1 は主装置の光送信回路、 1 2は主装置の光受信回路、 1 5— 1 、 1 5 — 2は光ファイバ、 1 8は従装置の光受信回路、 1 9は従 装置の光送信、回路、 2 1 は光分、岐回路、 2 2は光受信部、 2 3は駆 動部、 2 4は飽和増幅 · 減衰回路としての出力強度飽和型増幅変調 器である。  The present embodiment is a bidirectional optical transmission system for bidirectional transmission of a two-core optical fiber. FIG. 1 shows the configuration of the embodiment of the present invention. In FIG. 1, 11 is an optical transmission circuit of the main unit, 12 is an optical receiving circuit of the main unit, 15-1 and 15-2 are optical fibers, 18 is an optical receiving circuit of the slave unit, and 19 is an optical receiving circuit of the slave unit. 21 is an optical splitter / branch circuit, 22 is an optical receiver, 23 is a drive unit, and 24 is an output intensity saturated modulator as a saturation amplification / attenuation circuit. .
主装置と従装置で双方向伝送する方式の構成について図 1 ( a ) で説明する。 図 1 ( a ) において、 主装置の光送信回路 1 1 は光フ アイバ 1 5 — 1 を通して下り光信号を送信し、 従装置の光受信回路 1 8は当該下り光信号を受信する。 従装置の光送信回路 1 9は光フ アイバ 1 5 — 2を通して上り光信号を送信し、 主装置の光受信回路 1 2は当該上り、光信号き受信する。 図 1 ( b ) には、 従装置の光受 信回路 ΐ 8 と光送信回路 1 9 ヘッ ドエンド構成を示す。 図 1 ( b ) において、 従装置の光受信回路 1 8では、 光ファイバ 1 5 — 1 を 介して受信した下り光信号を、 光分岐回路 2 1で 2つに分岐する。 分岐された下り光信号を光受信部 2 2で検出し、 検出された下り信 号を光受信回路 1 8内で信号処理する。 出力強度飽和型増幅変調器 2 4は分岐された下り光信号の一部を駆動部 2 3からの上り信号で 飽和増幅、 減衰し、 上り光信号に変調する。 変調された上り光信号 は光ファイノ I 5 — 2を介して送信される。  The configuration of the method for bidirectional transmission between the master device and the slave device will be described with reference to Fig. 1 (a). In FIG. 1 (a), the optical transmission circuit 11 of the main unit transmits a downstream optical signal through the optical fiber 15-1, and the optical reception circuit 18 of the slave unit receives the downstream optical signal. The optical transmission circuit 19 of the slave device transmits an upstream optical signal through the optical fiber 15-2, and the optical reception circuit 12 of the master device receives the upstream optical signal. Fig. 1 (b) shows the head-end configuration of the optical receiving circuit # 8 and the optical transmitting circuit 19 of the slave device. In FIG. 1B, in the optical receiving circuit 18 of the slave device, the downstream optical signal received via the optical fiber 15-1 is split into two by the optical splitting circuit 21. The branched downstream optical signal is detected by the optical receiving unit 22, and the detected downstream signal is subjected to signal processing in the optical receiving circuit 18. The output intensity saturated amplification modulator 24 saturates and attenuates a part of the branched down optical signal with the up signal from the drive unit 23, and modulates it into the up optical signal. The modulated upstream optical signal is transmitted via the optical finos I5-2.
次に、 本構成での動作を説明する。 下り光信号の送信と受信の動 作を図 2に、 上り光信号の送信と受信の動作を図 3に示す。 図 2に おいて、 主装置の光送信回路では、 下り信号で変調した信号成分に バイアス成分を重畳し、 発光素子の駆動電流とする (図 2 ( a ) )。 発光素子の光出力は駆動電流に対して、 ほぼ直線的な関係にある ( 図 2 ( b ))。 その結果、 主装置の光送信回路は駆動電流の波形に近 い下り光信号出力を送信する (図 2 ( c ))。 従装置の光受信回路で は、 光受信回路入力の信号成分に対して閾値を設定して、 下り信号 の信号成分を検出する (図 2 ( d ))。 ここでは、 下り信号は強度変 調されて送受信する例を示したが、 位相変調や周波数変調等の変調 形式であってもよい。 これらの変調形式でも、 主装置の光送信回路 では、 信号成分にバイアス成分を重畳して送信し、 従装置の光受信 回路では信号成分から下り光信号成分を検出する。 Next, the operation in this configuration will be described. Figure 2 shows the transmission and reception operations of the downstream optical signal, and Figure 3 shows the transmission and reception operations of the upstream optical signal. In FIG. 2, in the optical transmission circuit of the main device, a bias component is superimposed on a signal component modulated by a downstream signal to obtain a drive current for a light emitting element (FIG. 2 (a)). The light output of the light-emitting element has a substantially linear relationship with the drive current ( Figure 2 (b)). As a result, the optical transmission circuit of the main unit transmits a downstream optical signal output close to the drive current waveform (Fig. 2 (c)). In the optical receiver circuit of the slave device, a threshold is set for the signal component of the optical receiver circuit input, and the signal component of the downstream signal is detected (Fig. 2 (d)). Here, an example is shown in which the downlink signal is transmitted and received after being intensity-modulated, but may be a modulation format such as phase modulation or frequency modulation. Even in these modulation formats, the optical transmission circuit of the main device transmits a signal component with a bias component superimposed thereon, and the optical reception circuit of the slave device detects a downstream optical signal component from the signal component.
図 3において、 下り光信号の一部を分岐して出力強度飽和型増幅 変調器に入力する (図 3 ( a ))。 出力強度飽和型増幅変調器は、 光 入力が小さい範囲では線形増幅するが、 光入力が大きくなると増幅 度は飽和し、 光入力レベルに関わらず光出力が一定となる (図 3 ( b ))。 さらに、 出力強度飽和型増幅変調器は、 制御端子から増幅度 を制御可能な増幅変調器であり、 増幅度を高く して飽和型増幅させ たり、 逆に増幅度を抑えて減衰させたりすることができる (図 3 ( b ))。 この出力強度飽和型増幅変調器に分岐した下り光信号を入力 すると、 下り光信号は信号成分にバイアス成分が重畳されているた め、 飽和型増幅によりバイアス成分は増幅され、 信号成分は圧縮さ れる (図 3 ( c ))。 さらに、 出力強度飽和型増幅変調器の制御端子 に従装置の光送信回路の駆動部からの上り信号を入力すると、 上り 信号に応じて増幅度が制御される結果、 飽和型増幅時にはバイアス 成分が増幅されるとともに信号成分が圧縮された高出力の光信号が 出力され、 増幅度が抑えられた減衰時にはバイアス成分と信号成分 が共に圧縮された低出力の光信号が出力される (図 3 ( c ))。 主装 置の光受信回路では、 光受信回路入力の信号成分に対して閾値を設 定して、 上り光信号の信号成分を検出する (図 3 ( d ))。  In Fig. 3, a part of the downstream optical signal is branched and input to the output intensity saturated amplifier (Fig. 3 (a)). The output-saturation-type amplifying modulator performs linear amplification in the range where the optical input is small, but as the optical input increases, the amplification level saturates and the optical output becomes constant regardless of the optical input level (Fig. 3 (b)). . Furthermore, the output intensity saturation amplification modulator is an amplification modulator whose amplification degree can be controlled from the control terminal.It can increase the amplification degree and perform the saturation amplification, or conversely, suppress the amplification degree and attenuate it. (Fig. 3 (b)). When the downstream optical signal branched into the output intensity saturation type modulator is input, the bias component is amplified by the saturation amplification because the bias component is superimposed on the signal component of the downstream optical signal, and the signal component is compressed. (Fig. 3 (c)). Furthermore, when an upstream signal from the drive unit of the optical transmission circuit of the device is input to the control terminal of the output intensity saturation amplification modulator, the amplification degree is controlled according to the upstream signal. As a result, the bias component is generated during the saturation amplification. A high-output optical signal that is amplified and the signal component is compressed is output, and a low-output optical signal is output in which both the bias component and the signal component are compressed during attenuation when the amplification is suppressed (Fig. 3 ( c)). The optical receiver circuit of the main unit sets a threshold value for the signal component input to the optical receiver circuit and detects the signal component of the upstream optical signal (Fig. 3 (d)).
ここで、 前記バイアス成分が前記信号成分の 5 0 %以上であると 、 強度変調した信号のマーク率が 5 0 %デューティの場合に、 前記 バイアス成分の光電力が前記信号成分の平均光電力以上になり、 出 力強度飽和型増幅変調器でバイアス成分を増幅することが容易とな る。 前記バイアス成分が前記信号成分の 1 0 0 %以上であると、 前 記バイアス成分の光電力が前記信号成分のピーク光電力以上になり 、 出力強度飽和型増幅変調器でバイアス成分を増幅することが一層 容易となる。 以下の実施の形態でも同様である。 Here, if the bias component is 50% or more of the signal component, and if the mark rate of the intensity-modulated signal is 50% duty, the optical power of the bias component is equal to or more than the average optical power of the signal component. Become out It becomes easy to amplify the bias component by the power intensity saturation type amplification modulator. When the bias component is equal to or more than 100% of the signal component, the optical power of the bias component becomes equal to or higher than the peak optical power of the signal component, and the bias component is amplified by the output intensity saturated amplification modulator. Becomes easier. The same applies to the following embodiments.
以上説明したように、 主装置の光送信回路が下り信号で変調した 信号成分にバイアス成分を重畳した下り光信号を光ファイバに送信 し、 従装置の光送信回路が受信した下り光信号の一部を飽和増幅 · 減衰回路によって上り信号で変調した上り光信号を送信することに より、 従装置側では、 発光素子を使用することなく、 双方向伝送を することができた。  As described above, the optical transmission circuit of the main device transmits the downstream optical signal in which the bias component is superimposed on the signal component modulated by the downstream signal to the optical fiber, and the optical transmission circuit of the slave device receives one of the received downstream optical signals. By transmitting an upstream optical signal whose section is modulated by an upstream signal by a saturation amplification / attenuation circuit, the slave device was able to perform bidirectional transmission without using a light emitting element.
(実施の形態 2 )  (Embodiment 2)
本実施の形態は、 1芯の光ファイバで方向多重双方向伝送する双 方向光伝送方式である。 本発明の実施の形態の構成を図 4に示す。 図 4において、 1 1 は主装置の光送信回路、 1 2は主装置の光受信 回路、 1 4は主装置の光合分岐回路、 1 5は光ファイバ、 1 7は従 装置の光合分岐回路、 1 8は従装置の光受信回路、 1 9は従装置の 光送信回路、 2 1 は光分岐回路、 2 2は光受信部、 2 3は駆動部、 2 4は飽和増幅 · 減衰回路としての出力強度飽和型増幅変調器であ る。  The present embodiment is a bidirectional optical transmission system in which directional multiplex bidirectional transmission is performed using a single-core optical fiber. FIG. 4 shows the configuration of the embodiment of the present invention. In FIG. 4, 11 is the optical transmission circuit of the main device, 12 is the optical receiving circuit of the main device, 14 is the optical coupling / branching circuit of the main device, 15 is an optical fiber, 17 is the optical coupling / branching circuit of the slave device, 18 is the optical receiver circuit of the slave device, 19 is the optical transmitter circuit of the slave device, 21 is the optical branching circuit, 22 is the optical receiver, 23 is the driver, 24 is the saturation amplification / attenuation circuit. This is an output intensity saturated amplification modulator.
主装置と従装置で双方向伝送する方式の構成について図 4 ( a ) で説明する。 図 4 ( a ) において、 主装置の光送信回路 1 1 は主装 置の光合分岐回路 1 4と光ファイバ 1 5を通して下り光信号を送信 し、 従装置の光受信回路 1 8は従装置の光合分岐回路 1 7を通して 前記下り光信号を受信する。 従装置の光送信回路 1 9は従装置の光 合分岐回路 1 7 と光ファイバ 1 5を通して上り光信号を送信し、 主 装置の光受信回路 1 2は主装置の光合分岐回路を通して前記上り光 信号を受信する。 図 4 ( b ) には、 従装置の光受信回路 1 8 と光送 信回路 1 9のヘッ ドエンド構成を示す。 図 4 ( b ) において、 従装 置の光受信回路 1 8では、 光分岐回路 2 1で従装置の光合分岐回路 1 7を介して受信した下り光信号を 2つに分岐する。 分岐した下り 光信号を光受信部 2 2で検出し、 検出した下り信号を光受信回路 1 8内で信号処理する。 出力強度飽和型増幅変調器 2 4は分岐した下 り光信号の一部を駆動部 2 3からの上り信号で飽和増幅、 減衰して 上り光信号に変調する。 変調された上り光信号は従装置の光合分岐 回路 1 7 と光ファイバ 1 5を介して送信される。 光合分岐回路 1 7 と光分岐回路 2 1は一体で構成してもよい。 Fig. 4 (a) shows the configuration of the bidirectional transmission method between the master device and the slave device. In FIG. 4 (a), the optical transmission circuit 11 of the main unit transmits a downstream optical signal through the optical coupling / branching circuit 14 of the main unit and the optical fiber 15, and the optical reception circuit 18 of the slave unit is connected to the slave unit. The downstream optical signal is received through the optical coupling / branching circuit 17. The optical transmission circuit 19 of the slave device transmits an upstream optical signal through the optical multiplexer / demultiplexer circuit 17 of the slave device and the optical fiber 15, and the optical receiver circuit 12 of the main device transmits the upstream optical signal through the optical multiplexer / demultiplexer circuit of the master device. Receive the signal. FIG. 4 (b) shows the head-end configuration of the optical receiving circuit 18 and the optical transmitting circuit 19 of the slave device. In Fig. 4 (b), In the optical receiving circuit 18 of the device, the downstream optical signal received by the optical branching circuit 21 via the optical combining / branching circuit 17 of the slave device is branched into two. The branched down optical signal is detected by the optical receiving unit 22, and the detected down signal is processed in the optical receiving circuit 18. The output-intensity-saturation-type amplifying modulator 24 amplifies and attenuates a part of the branched down optical signal with the up signal from the drive unit 23, attenuates it, and modulates the up light signal. The modulated upstream optical signal is transmitted via the optical multiplexing / branching circuit 17 of the slave device and the optical fiber 15. The optical branching circuit 17 and the optical branching circuit 21 may be integrally formed.
次に、 本構成での動作を説明する。 下り光信号の送信と受信の動 作は図 2 と、 上り光信号の送信と受信の動作は図 3 と同様である。 異なるのは、 主装置と従装置にそれぞれ光合分岐回路 1 4 、 1 7 を 備えることにより、 1芯の光ファイバで双方向伝送が可能になって いることである。 これらの光合分岐回路によって、 上り光信号と下 り光信号が分離される。 光合分岐回路には、 方向性光結合回路や光 サ一キユレ一夕等が適用できる。 主装置の光送信回路及び光受信回 路、 並びに従装置の光送信回路及び光受信回路は、 実施の形態 1 と 同じ動作をする。  Next, the operation in this configuration will be described. The operation of transmitting and receiving downstream optical signals is the same as in Fig. 2, and the operation of transmitting and receiving upstream optical signals is the same as in Fig. 3. The difference is that the provision of the optical coupling / branching circuits 14 and 17 in the master device and the slave device respectively enables bidirectional transmission with a single-core optical fiber. These optical couplers separate the upstream optical signal from the downstream optical signal. A directional optical coupling circuit, an optical circuit, or the like can be applied to the optical coupling / branching circuit. The optical transmission circuit and the optical reception circuit of the main device, and the optical transmission circuit and the optical reception circuit of the slave device operate in the same manner as in the first embodiment.
1芯の光ファイバで方向多重双方向伝送する双方向光伝送方式に おいては、 下り信号と上り信号が同一波長で同一光ファイバ上を伝 送される。 そのため、 主装置で上り信号を受信する場合、 光フアイ バの途中で反射した下り信号と相互干渉する場合がある。 本実施の 形態では、 発光素子の駆動電流を制御して、 下り信号に信号成分が 重畳しているため、 下り信号光のスペク トル幅を広くすることもで きる。 信号光のスペク トル幅が広くなると、 上り信号と線路途中で 反射した下り信号との相互干渉が抑制され、 上り信号に加算する雑 音を抑圧することが可能となる。  In a bidirectional optical transmission system in which direction-division multiplex bidirectional transmission is performed using a single optical fiber, a downstream signal and an upstream signal are transmitted on the same optical fiber at the same wavelength. Therefore, when the main unit receives an upstream signal, it may interfere with a downstream signal reflected in the middle of the optical fiber. In the present embodiment, since the driving current of the light emitting element is controlled and the signal component is superimposed on the downstream signal, the spectrum width of the downstream signal light can be widened. When the spectrum width of the signal light is widened, mutual interference between the upstream signal and the downstream signal reflected in the middle of the line is suppressed, and noise added to the upstream signal can be suppressed.
従って、 主装置の光送信回路が下り信号で変調した信号成分にバ ィァス成分を重畳した下り光信号を光ファイバに送信し、 従装置の 光送信回路が受信した下り光信号の一部を飽和増幅 · 減衰回路によ つて上り信号で変調した上り光信号を光ファイバに送信する構成と することにより、 従装置側では、 発光素子を使用することなく、 双 方向伝送をすることができた。 Therefore, the optical transmission circuit of the master device transmits a downstream optical signal in which a bias component is superimposed on the signal component modulated by the downstream signal to the optical fiber, and a part of the downstream optical signal received by the optical transmission circuit of the slave device is saturated. Amplification / attenuation circuit By using a configuration in which the upstream optical signal modulated by the upstream signal is transmitted to the optical fiber, the slave device can perform bidirectional transmission without using a light emitting element.
また、 従装置の光送信回路は出力強度飽和型増幅変調器によって 、 下り光信号と同じ波長の上り光信号を送信するため、 光合分岐回 路の特性に波長依存性があっても、 上り光信号の波長を高精度に制 御したり、 維持したりする必要はなくなつた。  In addition, since the optical transmission circuit of the slave device transmits an upstream optical signal having the same wavelength as the downstream optical signal by using the output intensity-saturated amplifying modulator, even if the characteristics of the optical multiplexing / demultiplexing circuit have wavelength dependence, the upstream optical signal is transmitted. It is no longer necessary to control and maintain the signal wavelength with high precision.
さらに、 本従装置の光送信回路において、 半導体光増幅器の出力 強度飽和増幅機能を広範囲の波長にわたって動作させると、 波長ご とに従装置の種類が異なるのではなく、 同一種の従装置を任意の従 装置に適用することができる。 即ち、 従装置間で、 相互運用性 (ィ ン夕オペラピリティ) を確保することが可能となった。  Furthermore, when the output intensity saturation amplification function of the semiconductor optical amplifier is operated over a wide range of wavelengths in the optical transmission circuit of the slave device, the type of slave device is not different for each wavelength, but the same type of slave device is optional. The present invention can be applied to a slave device. In other words, interoperability (interoperability) between slave devices has become possible.
(実施の形態 3 )  (Embodiment 3)
本実施の形態は、 主装置と複数の従装置で 2芯光ファイバ双方向 · 波長多重マルチポイント伝送する双方向光伝送方式である。 本発 明の実施の形態の構成を図 5に示す。 図 5 において、 1 1 _ 1〜 1 1 一 Nは主装置の光送信回路、 1 2 — 1〜 1 2 — Nは主装置の光受 信回路、 1 3 — 1 、 1 3 — 2は主装置の波長多重回路、 1 5 _ 1 、 1 5 — 2は光ファイバ、 1 6 — 1 、 1 6 — 2は光ファイバの途中に 設けられた波長多重回路、 1 8 — :! 〜 1 8 — Nは従装置の光受信回 路、 1 9 _ 1 〜 1 9 — Nは従装置の光送信回路である。 ここでは、 2以上の複数を表すときに記号 Nを用いた。 例えば、 光送信回路 1 1 一 1 〜 1 1 一 Nは 2以上の複数の光送信回路を表す。 図 5におい て、 下方向の矢印は下り、 上方向の矢印は上りの伝送方向を表す。 主装置と複数の従装置で双方向伝送する方式の構成について説明 する。 図 5において、 主装置の複数の光送信回路 1 1 一 1 〜 1 1 一 Nは下り信号で変調した信号成分にバイアス成分を重畳したそれぞ れの下り光信号を主装置の波長多重回路 1 3 — 1 に送信する。 光送 信回路 1 1 - 1 〜 1 1 一 Nの光信号の波長はそれぞれ予め割り当て られている ( λ 1 λ 2、 · , λ Ν)。 波長多重回路 1 3 — 1は、 複数 の光送信回路 1 1 一 1〜 1 1 一 Νから送信された、 異なる波長 ( λ 丄〜 !^) の下り光信号を光ファイバ 1 5 — 1 に波長多重する。 光 ファイノ 1 5 — 1 の途中に設けられた波長多重回路 1 6 _ 1 は、 そ れぞれの下り光信号を波長に応じてそれぞれの従装置に向けて波長 分離する。 それぞれの従装置の光受信回路 1 8 — 1〜 1 8— Νは光 ファイバ 1 5 — 1 を通して受信した下り光信号から信号成分を検出 する。 それぞれの従装置の光送信回路 1 9 一 :!〜 1 9 一 Νは受信し た下り光信号の一部を飽和増幅 · 減衰回路によって上り信号で変調 した上り光信号を光ファイバ 1 5— 2に送信する。 従装置の光送信 回路の出力強度飽和型増幅変調器で下り光信号を飽和増幅するため 、 送信する波長は下り光信号と同じである。 光ファイバ 1 5 — 2の 途中に設けられた波長多重回路 1 6 — 2は複数の光送信回路 1 9 一The present embodiment is a bidirectional optical transmission system in which a two-core optical fiber bidirectional / wavelength multiplex multipoint transmission is performed between a main device and a plurality of slave devices. FIG. 5 shows the configuration of the embodiment of the present invention. In FIG. 5, 1 1 _ 1 to 1 1 1 N are the optical transmission circuit of the main unit, 1 2 — 1 to 1 2 — N are the optical reception circuit of the main unit, and 13 1 and 1 3 2 are the main units. 15-1 and 15-2 are optical fibers, 16-1 and 16-2 are wavelength-division multiplexing circuits provided in the middle of the optical fiber, and 18-8 :! 1 18 —N is the optical receiving circuit of the slave, and 19 _ 1 to 19 — N is the optical transmitting circuit of the slave. Here, the symbol N is used to represent two or more. For example, the optical transmission circuits 11 1 1 to 11 1 N represent two or more optical transmission circuits. In FIG. 5, the downward arrow indicates the downward transmission direction, and the upward arrow indicates the upward transmission direction. The configuration of a system for performing bidirectional transmission between a main device and a plurality of slave devices will be described. In FIG. 5, a plurality of optical transmission circuits 11 1 to 11 N of the main unit are configured to superimpose a bias component on a signal component modulated by the downstream signal and to transmit each downstream optical signal to the wavelength multiplexing circuit 1 of the main unit. 3—Send to 1. Optical transmission circuit 1 1-1 to 1 1 1 N (Λ 1 λ 2 , ·, λ Ν ). The wavelength division multiplexing circuit 13-1 converts the downstream optical signals of different wavelengths (λ 丄 ~! ^) Transmitted from the plurality of optical transmission circuits 111-1-11 to the optical fiber 15-1. Multiplex. The wavelength multiplexing circuit 16 _ 1 provided in the middle of the optical fino 15-1 separates the wavelength of each downstream optical signal toward each slave device according to the wavelength. The optical receiving circuits 18-1 to 18-Ν of each slave device detect signal components from the downstream optical signal received through the optical fiber 15-1. The optical transmission circuit of each slave device 1 9 1:! 1-19 transmits an upstream optical signal, which is obtained by modulating a part of the received downstream optical signal with an upstream signal by a saturation amplification / attenuation circuit, to an optical fiber 15-2. Since the downstream optical signal is saturated and amplified by the output intensity saturated amplification modulator of the optical transmission circuit of the slave device, the wavelength to be transmitted is the same as the downstream optical signal. The wavelength multiplexing circuit 16-2 provided in the middle of the optical fiber 15-2 is composed of a plurality of optical transmission circuits 1 9
1〜 1 9 — Νから送信された、 異なる波長 ( A i A w) の上り光 信号を主装置に向けて波長多重する。 主装置の波長多重回路 1 3 — 2は複数の従装置の光送信回路 1 9 — :!〜 1 9 — Nから送信された1 to 19 — Wavelength multiplexes upstream optical signals of different wavelengths (AiAw) transmitted from Ν toward the main unit. The wavelength division multiplexing circuit 1 3-2 of the main unit is transmitted from the optical transmission circuit of multiple slave units 1 9-:! ~ 1 9-N
、 異なる波長 ( λ i〜 λ Ν ) の上り光信号を波長毎に主装置の光受 信回路 1 2 — :!〜 1 2 — Νに向けて波長分離する。 主装置の複数の 光受信回路 1 2— 1〜 1 2 — Νは受信した上り光信号から上り信号 を検出する。 The upstream optical signals of different wavelengths (λ i to λ Ν) are transmitted for each wavelength to the optical receiver circuit 1 2 of the main unit. 1 1 2 — Separate the wavelength toward Ν. The plurality of optical receiver circuits 12-1 to 12-2 in the main unit detect upstream signals from the received upstream optical signals.
次に、 本構成での動作を説明する。 下り光信号の送信と受信の動 作は図 2 と、 上り光信号の送信と受信の動作は図 3 と同様である。 異なるのは、 主装置に波長多重回路 1 3 — 1 と 1 3 — 2、 光フアイ バの途中に波長多重回路 1 6 — 1 と 1 6 — 2を備えることにより、 主装置と複数の従装置で波長多重マルチポイン ト伝送が可能になつ ていることである。 波長多重回路 1 6— 1 と 1 6 — 2 によって、 上 り光信号と下り光信号が多重、 分離される。 主装置の光送信回路及 び光受信回路、 並びに従装置の光送信回路及び光受信回路は、 実施 の形態 1 と同じ動作をする。 従って、 主装置の光送信回路が下り信号で変調した信号成分にバ ィァス成分を重畳した下り光信号を光ファイバに送信し、 従装置の 光送信回路が受信した下り光信号の一部を飽和増幅 · 減衰回路によ つて上り信号で変調した上り光信号を送信する構成とすることによ り、 従装置側では、 発光素子を使用することなく、 双方向伝送をす ることができた。 Next, the operation in this configuration will be described. The operation of transmitting and receiving downstream optical signals is the same as in Fig. 2, and the operation of transmitting and receiving upstream optical signals is the same as in Fig. 3. The difference is that the main unit has wavelength multiplexing circuits 13-1 and 13-2, and the wavelength multiplexing circuits 16-1 and 16-2 in the middle of the optical fiber. Thus, wavelength multiplexing multipoint transmission has become possible. The upstream optical signal and the downstream optical signal are multiplexed and demultiplexed by the wavelength multiplexing circuits 16-1 and 16-2. The optical transmission circuit and the optical reception circuit of the main device, and the optical transmission circuit and the optical reception circuit of the slave device operate in the same manner as in the first embodiment. Therefore, the optical transmission circuit of the master device transmits a downstream optical signal in which a bias component is superimposed on the signal component modulated by the downstream signal to the optical fiber, and a part of the downstream optical signal received by the optical transmission circuit of the slave device is saturated. By employing a configuration in which an upstream optical signal modulated by an upstream signal is transmitted by the amplification / attenuation circuit, the slave device can perform bidirectional transmission without using a light emitting element.
また、 従装置の光送信回路は出力強度飽和型増幅変調器によって 、 下り光信号と同じ波長の上り光信号を送信するため、 波長多重回 路の波長特性に対して従装置側の送信回路では上り光信号の波長を 高精度に一致させたり、 維持したりする必要はなくなつた。  Also, since the optical transmission circuit of the slave device transmits an upstream optical signal having the same wavelength as the downstream optical signal by the output intensity saturated amplification modulator, the transmission circuit of the slave device on the wavelength characteristic of the wavelength multiplexing circuit It is no longer necessary to match or maintain the wavelength of the upstream optical signal with high precision.
さらに、 本従装置の光送信回路において、 半導体光増幅器の出力 強度飽和増幅機能を広範囲の波長にわたって動作させると、 波長ご とに従装置の種類が異なるのではなく、 同一種の従装置を任意の従 装置に適用することができる。 即ち、 従装置間で、 相互運用性 (ィ ンタオペラピリティ) を確保することが可能となった。  Furthermore, when the output intensity saturation amplification function of the semiconductor optical amplifier is operated over a wide range of wavelengths in the optical transmission circuit of the slave device, the type of slave device is not different for each wavelength, but the same type of slave device is optional. The present invention can be applied to a slave device. In other words, interoperability (interoperability) can be secured between slave devices.
(実施の形態 4 )  (Embodiment 4)
本実施の形態は、 主装置と複数の従装置で 1芯の光ファイバで方 向多重双方向 · 波長多重マルチポイント伝送する双方向光伝送方式 である。 本発明の実施の形態の構成を図 6に示す。 図 6において、 1 1 — 1〜 : 1 1 — Nは主装置の光送信回路、 1 2 _ 1〜 1 2 _ Nは 主装置の光受信回路、 1 3 — 1、 1 3 — 2は主装置の波長多重回路 、 1 4は主装置の光合分岐回路、 1 5は光ファイバ、 1 6は光ファ ィバの途中に設けられた波長多重回路、 1 7 — :!〜 1 7 — Nは従装 置の光合分岐回路、 1 8 — :!〜 1 8 — Nは従装置の光受信回路、 1 9 — 1〜 1 9 _ Nは従装置の光送信回路である。 ここでは、 2以上 の複数を表すときに記号 Nを用いた。 例えば、 光送信回路 1 1 — 1 〜 1 1 _ Nは 2以上の複数の光送信回路を表す。 図 6 において、 下 方向の矢印は下り、 上方向の矢印は上り、 上下両方向の矢印は上り 下りの双方向の伝送方向を表す。 主装置と複数の従装置で双方向伝送する方式の構成について説明 する。 図 6 において、 主装置の複数の光送信回路 1 1 一 1〜 1 1 一 Nは下り信号で変調した信号成分にバイアス成分を重畳したそれぞ れの下り光信号を主装置の波長多重回路 1 3 — 1 に向けて送信する 。 光送信回路 1 1 — 1〜 1 1 _ Nの下り光信号の波長は予め割り当 てられている ( λ 1 λ 2、 · · λ Ν)。 主装置の波長多重回路 1 3 — 1 は、 複数の光送信回路 1 1 — 1〜 1 1 _ Νから送信された、 異な る波長 (ぇ ェ〜 !^) の下り光信号を波長多重する。 主装置の光合 分岐回路 1 4はこれらの下り光信号を光ファイバ 1 5 _ 1 に合流さ せる。 光ファイバ 1 5の途中に設けられた波長多重回路 1 6は、 そ れぞれの下り光信号を波長に応じてそれぞれの従装置に向けて波長 分離する。 それぞれの従装置の光合分岐回路 1 7 — :!〜 1 7 — Νは 下り光信号を対応する光受信回路 1 8 — :!〜 1 8 — Νに分岐する。 光受信回路 1 8 — 1〜 1 8— Νは受信した下り光信号から信号成分 を検出する。 The present embodiment is a bidirectional optical transmission system in which a master device and a plurality of slave devices transmit one-core optical fiber in a direction multiplex bidirectional / wavelength multiplex multipoint transmission. FIG. 6 shows the configuration of the embodiment of the present invention. In Fig. 6, 1 1-1-: 1 1-N is the optical transmission circuit of the main unit, 1 2 _ 1-12 _ N is the optical receiving circuit of the main unit, 1 3-1, 1 3-2 is the main unit Wavelength multiplexing circuit of the device, 14 is an optical multiplexing / branching circuit of the main device, 15 is an optical fiber, 16 is a wavelength multiplexing circuit provided in the middle of the optical fiber, and 17-:! ~ 1 7 — N is the optical coupling / branching circuit of the slave device, 1 8 —:! 1 18 —N is the optical receiver circuit of the slave device, and 19 — 1 to 19 _N is the optical transmitter circuit of the slave device. Here, the symbol N is used to represent two or more. For example, the optical transmission circuits 11-1 to 11_N represent two or more optical transmission circuits. In FIG. 6, the downward arrow indicates the downward direction, the upward arrow indicates the upward direction, and the up and down directions indicate the upward and downward bidirectional transmission directions. The configuration of a system for performing bidirectional transmission between a main device and a plurality of slave devices will be described. In FIG. 6, a plurality of optical transmission circuits 1 1 1 1 to 1 1 1 N of the main unit transmit each downstream optical signal obtained by superimposing a bias component on a signal component modulated by a downstream signal, to a wavelength multiplexing circuit 1 of the main unit. 3—Send to 1. Optical transmitter circuit 1 1 - 1 to 1 1 _ wavelength of the downstream optical signal of N is previously assigned (λ 1 λ 2, · · λ Ν). The wavelength multiplexing circuit 13-1 of the main unit wavelength-multiplexes downstream optical signals of different wavelengths (ぇ to! ^) Transmitted from the plurality of optical transmission circuits 11-1 to 11_Ν. The optical combining / branching circuit 14 of the main device combines these downstream optical signals with the optical fiber 15_1. The wavelength multiplexing circuit 16 provided in the middle of the optical fiber 15 separates each downstream optical signal toward each slave device according to the wavelength. Optical coupling / branching circuit of each slave device 1 7 —:! 1 1 7 — Ν is an optical receiving circuit that supports downstream optical signals 1 8 —:! ~ 1 8 — branch to Ν. The optical receiver circuit 18-1 to 18-detects the signal component from the received downstream optical signal.
それぞれの従装置の光送信回路 1 9 一 :!〜 1 9一 Νは受信した下 り光信号の一部を光分岐回路 (図示せず) によって分岐して、 飽和 増幅 · 減衰回路によって上り信号で変調した上り光信号を送信する 。 前記下り光信号の一部を分岐する光分岐回路と前記光合分岐回路 1 7を一体で構成してもよい。 下り光信号は従装置の光送信回路の 出力強度飽和型増幅変調器によって飽和増幅されるため、 送信する 波長は下り光信号と同じである。 従装置の光合分岐回路 1 7 — :!〜 1 7 — Νは上り光信号を光ファイバ 1 5に合流させる。 光ファイバ 1 5の途中に設けられた波長多重回路 1 6は複数の光送信回路 1 9 一 :!〜 1 9 — Νから送信された、 異なる波長 ( 丄〜 !^) の上り 光信号を主装置に向けて波長多重する。 主装置の波長多重回路 1 3 一 2は複数の従装置の光送信回路 1 9 _ 1〜 1 9一 Νから送信され た、 異なる波長 ( λ ;!〜 λ Ν) の上り光信号を波長毎に主装置の光 受信回路 1 2— 1〜 1 2 — Νに向けて波長分離する。 主装置の複数 の光受信回路 1 2 — 1 〜 1 2 — Nは受信した上り光信号からそれぞ れ上り信号を検出する。 The optical transmission circuit of each slave device 1 9 1:! In 1910, a part of the received optical signal is branched by an optical branching circuit (not shown), and an upstream optical signal modulated by an upstream signal by a saturation amplification / attenuation circuit is transmitted. The optical branching circuit 17 for branching a part of the downstream optical signal and the optical combining / branching circuit 17 may be integrally configured. Since the downstream optical signal is saturated and amplified by the output intensity saturation amplification modulator of the optical transmission circuit of the slave device, the wavelength to be transmitted is the same as the downstream optical signal. Optical coupling / branching circuit of slave device 1 7 —:! 1 1 7 — Ν joins the upstream optical signal to the optical fiber 15. The wavelength division multiplexing circuit 16 provided in the middle of the optical fiber 15 is composed of a plurality of optical transmission circuits 19 1:! 1 1 9 — Wavelength multiplexes upstream optical signals of different wavelengths (丄 to! ^) Transmitted from Ν toward the main unit. The wavelength multiplexing circuits 13 1 and 12 of the main unit transmit upstream optical signals of different wavelengths (λ ;! To λ ) transmitted from the optical transmission circuits 19 _ 1 to 19 In the main unit, the wavelength is separated toward the optical receiver circuit 12-1-1 2-—. Multiple of main units The optical receiving circuits 1 2-1 to 1 2 -N respectively detect upstream signals from the received upstream optical signals.
次に、 本構成での動作を説明する。 下り光信号の送信と受信の動 作は図 2 と、 上り光信号の送信と受信の動作は図 3 と同様である。 異なるのは、 主装置に波長多重回路 1 3 _ 1 と 1 3 _ 2、 及び光合 分岐回路 1 4を、 光ファイバの途中に波長多重回路 1 6を、 複数の 従装置に光合分岐回路 1 7 — 2〜 1 7 — Nを備えることにより、 主 装置と複数の従装置で 1芯光ファイバ方向多重双方向 · 波長多重マ ルチポイント伝送が可能になっていることである。 これらの波長多 重回路と光合分岐回路によって、 複数の上り光信号と複数の下り光 信号が多重、 又は分離される。 主装置の光送信回路及び光受信回路 Next, the operation in this configuration will be described. The operation of transmitting and receiving downstream optical signals is the same as in Fig. 2, and the operation of transmitting and receiving upstream optical signals is the same as in Fig. 3. The difference is that the wavelength division multiplexing circuits 13 _ 1 and 13 _ 2 and the optical multiplexing / branching circuit 14 are provided in the main unit, the wavelength multiplexing circuit 16 is provided in the middle of the optical fiber, and the optical multiplexing and branching circuit 17 is provided in a plurality of slave units. — 2 to 17 — N means that single-core optical fiber direction multiplexing bidirectional and wavelength multiplexing multipoint transmission is possible between the main unit and multiple slave units. A plurality of upstream optical signals and a plurality of downstream optical signals are multiplexed or demultiplexed by these wavelength multiplexing circuits and optical multiplexing / branching circuits. Optical transmission circuit and optical reception circuit of main unit
、 並びに従装置の光送信回路及び光受信回路は、 実施の形態 1 と同 じ動作をする。 , And the optical transmission circuit and the optical reception circuit of the slave device operate in the same manner as in the first embodiment.
1芯の光ファイバで方向多重双方向 · 波長多重マルチポイント伝 送する双方向光伝送方式においては、 下り信号と上り信号が同一波 長で同一光ファイバ上を伝送される。 そのため、 主装置で上り信号 を受信する場合、 光ファイバの途中で反射した下り信号と相互千渉 する場合がある。 本実施の形態では、 発光素子の駆動電流を制御し て、 下り信号に信号成分が重畳しているため、 下り信号光のスぺク トル幅を広くすることもできる。 信号光のスペク トル幅が広くなる と、 上り信号と線路途中で反射した下り信号との相互干渉が抑制さ れ、 上り信号に加算する雑音を抑圧することが可能となる。  In a bidirectional optical transmission system in which direction-division multiplex bidirectional / wavelength multiplex multipoint transmission is performed using a single optical fiber, a downstream signal and an upstream signal are transmitted on the same optical fiber with the same wavelength. Therefore, when an upstream signal is received by the main unit, it may interfere with a downstream signal reflected in the middle of an optical fiber. In the present embodiment, the drive current of the light emitting element is controlled so that the signal component is superimposed on the downstream signal, so that the spectrum width of the downstream signal light can be increased. When the spectrum width of the signal light is widened, mutual interference between the upstream signal and the downstream signal reflected in the middle of the line is suppressed, and noise added to the upstream signal can be suppressed.
従って、 主装置の光送信回路が下り信号で変調した信号成分にバ ィァス成分を重畳した下り光信号を光ファイバに送信し、 従装置の 光送信回路が受信した下り光信号の一部を飽和増幅 · 減衰回路によ つて上り信号で変調した上り光信号を光ファイバに送信する構成と することにより、 従装置側では、 発光素子を使用することなく、 双 方向伝送をすることができた。  Therefore, the optical transmission circuit of the master device transmits a downstream optical signal in which a bias component is superimposed on the signal component modulated by the downstream signal to the optical fiber, and a part of the downstream optical signal received by the optical transmission circuit of the slave device is saturated. By using a configuration in which the upstream optical signal modulated with the upstream signal by the amplification / attenuation circuit is transmitted to the optical fiber, the slave device can perform bidirectional transmission without using a light emitting element.
また、 従装置の光送信回路は出力強度飽和型増幅変調器によって 、 下り光信号と同じ波長の上り光信号を送信するため、 波長多重回 路の波長特性に対して従装置側の送信回路では上り光信号の波長を 高精度に一致させたり、 維持したりする必要はなくなつた。 In addition, the optical transmission circuit of the slave device is output-saturation type amplification modulator. In order to transmit the upstream optical signal with the same wavelength as the downstream optical signal, the transmission circuit on the slave device side matches or maintains the wavelength of the upstream optical signal with high accuracy with respect to the wavelength characteristics of the wavelength multiplexing circuit. The need is gone.
さらに、 本従装置の光送信回路において、 半導体光増幅器の出力 強度飽和増幅機能を広範囲の波長にわたって動作させると、 波長ご とに従装置の種類が異なるのではなく、 同一種の従装置を任意の従 装置に適用することができる。 即ち、 従装置間で、 相互運用性 (ィ ン夕オペラピリティ) を確保することが可能となった。  Furthermore, when the output intensity saturation amplification function of the semiconductor optical amplifier is operated over a wide range of wavelengths in the optical transmission circuit of the slave device, the type of slave device is not different for each wavelength, but the same type of slave device is optional. The present invention can be applied to a slave device. In other words, interoperability (interoperability) between slave devices has become possible.
(実施の形態 5 )  (Embodiment 5)
本実施の形態は、 主装置と複数の従装置で 1芯光ファイバ方向多 重双方向 · 波長多重マルチポイント伝送する双方向光伝送方式であ る。 本発明の実施の形態の構成を図 7 に示す。 図 7において、 1 1 一 1 〜 1 1 — Nは主装置の光送信回路、 1 2 — 1 〜 1 2 — Nは主装 置の光受信回路、 1 3は主装置の波長多重回路、 1 4一 :!〜 1 4 一 Nは主装置の光合分岐回路、 1 5は光ファイバ、 1 6は光ファイバ の途中に設けられた波長多重回路、 1 7 — :!〜 1 7 — Nは従装置の 光合分岐回路、 1 8 — :!〜 1 8— Nは従装置の光受信回路、 1 9 一 1〜 1 9 — Nは従装置の光送信回路である。 ここでは、 2以上の複 数を表すときに記号 Nを用いた。 例えば、 光送信回路 1 1 _ 1〜 1 1 — Nは 2以上の複数の光送信回路を表す。 図 7 において、 下方向 の矢印は下り、 上方向の矢印は上り、 上下両方向の矢印は上り下り の双方向の伝送方向を表す。  The present embodiment is a bidirectional optical transmission system in which a single device and a plurality of slave devices perform single-core optical fiber direction multiplex bidirectional / wavelength multiplex multipoint transmission. FIG. 7 shows the configuration of the embodiment of the present invention. In FIG. 7, 1 1 1 to 1 1 —N is the optical transmission circuit of the main unit, 1 2 — 1 to 1 2 —N is the optical receiving circuit of the main unit, 13 is the wavelength multiplexing circuit of the main unit, 1 41 :! ~ 14 1 N is the optical branching circuit of the main unit, 15 is the optical fiber, 16 is the wavelength multiplexing circuit provided in the middle of the optical fiber, 1 7-:! ~ 1 7 — N is the optical coupling / branching circuit of the slave, 1 8 —:! .About.18-N is an optical receiving circuit of the slave device, and 19-11-1-19-N is an optical transmitting circuit of the slave device. Here, the symbol N is used to represent two or more. For example, the optical transmission circuits 11_1 to 11-N represent two or more optical transmission circuits. In FIG. 7, the downward arrow indicates the downward direction, the upward arrow indicates the upward direction, and the up and down directions indicate the upward and downward bidirectional transmission directions.
主装置と複数の従装置で双方向伝送する方式の構成と動作につい て説明する。 図 7において、 実施の形態 4との相違点は、 主装置の 光合分岐回路と波長多重回路の配置である。 つまり、 実施の形態 4 とは、 主装置の波長多重回路と光合分岐回路との接続が逆になつて いる。 光合分岐回路と波長多重回路は共に線形回路のため、 接続の 順番を入れ替えても同じ動作となる。 光合分岐回路と波長多重回路 の光損失、 必要個数によって実施の形態 4と実施の形態 5のいずれ かが選択される。 The configuration and operation of a system for performing bidirectional transmission between a master device and a plurality of slave devices will be described. In FIG. 7, the difference from Embodiment 4 is the arrangement of the optical multiplexing / branching circuit and the wavelength multiplexing circuit of the main device. That is, the connection between the wavelength multiplexing circuit and the optical multiplexing / branching circuit of the main device is reversed from that of the fourth embodiment. Since the optical multiplexing / branching circuit and the wavelength multiplexing circuit are both linear circuits, the same operation is performed even if the order of connection is changed. Either Embodiment 4 or Embodiment 5 depending on the optical loss and required number of optical coupling / branching circuits and wavelength division multiplexing circuits Is selected.
1芯の光ファイバで方向多重双方向 · 波長多重マルチポイント伝 送する双方向光伝送方式においては、 下り信号と上り信号が同一波 長で同一光ファイバ上を伝送される。 そのため、 主装置で上り信号 を受信する場合、 光ファイバの途中で反射した下り信号と相互干渉 する場合がある。 本実施の形態では、 発光素子の駆動電流を制御し て、 下り信号に信号成分が重畳しているため、 下り信号光のスぺク トル幅を広くすることもできる。 信号光のスぺク トル幅が広くなる と、 上り信号と線路途中で反射した下り信号との相互干渉が抑制さ れ、 上り信号に加算する雑音を抑圧することが可能となる。  In a bidirectional optical transmission system in which direction-division multiplex bidirectional / wavelength multiplex multipoint transmission is performed using a single optical fiber, a downstream signal and an upstream signal are transmitted on the same optical fiber with the same wavelength. Therefore, when the main unit receives an upstream signal, it may interfere with a downstream signal reflected in the middle of the optical fiber. In the present embodiment, the drive current of the light emitting element is controlled so that the signal component is superimposed on the downstream signal, so that the spectrum width of the downstream signal light can be increased. When the spectrum width of the signal light is widened, mutual interference between the upstream signal and the downstream signal reflected in the middle of the line is suppressed, and noise added to the upstream signal can be suppressed.
従って、 主装置の光送信回路が下り信号で変調した信号成分にバ ィァス成分を重畳した下り光信号を光ファイバに送信し、 従装置の 光送信回路が受信した下り光信号の一部を飽和増幅 · 減衰回路によ つて上り信号で変調した上り光信号を光ファイバに送信する構成と することにより、 従装置側では、 発光素子を使用することなく、 双 方向伝送をすることができた。  Therefore, the optical transmission circuit of the master device transmits a downstream optical signal in which a bias component is superimposed on the signal component modulated by the downstream signal to the optical fiber, and a part of the downstream optical signal received by the optical transmission circuit of the slave device is saturated. By using a configuration in which the upstream optical signal modulated with the upstream signal by the amplification / attenuation circuit is transmitted to the optical fiber, the slave device can perform bidirectional transmission without using a light emitting element.
また、 従装置の光送信回路は出力強度飽和型増幅変調器によって 、 下り光信号と同じ波長の上り光信号を送信するため、 波長多重回 路の波長特性に対して従装置側の送信回路では上り光信号の波長を 高精度に一致させたり、 維持したりする必要はなくなつた。  Also, since the optical transmission circuit of the slave device transmits an upstream optical signal having the same wavelength as the downstream optical signal by the output intensity saturated amplification modulator, the transmission circuit of the slave device on the wavelength characteristic of the wavelength multiplexing circuit It is no longer necessary to match or maintain the wavelength of the upstream optical signal with high precision.
さらに、 本従装置の光送信回路において、 半導体光増幅器の出力 強度飽和増幅機能を広範囲の波長にわたって動作させると、 波長ご とに従装置の種類が異なるのではなく、 同一種の従装置を任意の従 装置に適用することができる。 即ち、 従装置間で、 相互運用性 (ィ ン夕オペラピリティ) を確保することが可能となった。  Furthermore, when the output intensity saturation amplification function of the semiconductor optical amplifier is operated over a wide range of wavelengths in the optical transmission circuit of the slave device, the type of slave device is not different for each wavelength, but the same type of slave device is optional. The present invention can be applied to a slave device. In other words, interoperability (interoperability) between slave devices has become possible.
(実施の形態 6 )  (Embodiment 6)
出力強度飽和型増幅変調器を備える光送受信装置について説明す る。 通常の半導体光増幅器は、 入力光に対して出力光が線形増幅さ れる領域を使用して光増幅する。 一方、 出力強度飽和型増幅変調器 は、 半導体光増幅器において入力光に対して出力光の強度が飽和増 幅する領域を積極的に利用し、 かつ変調も行うようにしたものであ る。 出力強度飽和型増幅変調器は入力光を増幅するだけのため、 出 力光の波長は入力光に追随する。 An optical transmission / reception device including an output intensity saturated amplification modulator will be described. An ordinary semiconductor optical amplifier performs optical amplification using a region where output light is linearly amplified with respect to input light. On the other hand, the output intensity saturated amplification modulator In the semiconductor optical amplifier, a region where the intensity of output light is saturated and amplified with respect to input light is positively used and modulation is performed. Since the output intensity-saturated modulator only amplifies the input light, the wavelength of the output light follows the input light.
出力強度飽和型増幅変調器の概略構造を図 8 に示す。 図 8におい て、 3 1は出力強度飽和型増幅変調器、 3 3は増幅変調部、 3 4は 出射口である。 図 8において、 入力光に対して、 増幅変調部 3 3で 制御端子 (図示せず) からの入力信号により飽和増幅と減衰を行う 。 飽和増幅と減衰により、 増幅変調された出力光は出射口 3 4から 出力される。 このように、 飽和増幅と減衰により、 入力信号で変調 することができる。  Fig. 8 shows the schematic structure of the output intensity saturated amplification modulator. In FIG. 8, reference numeral 31 denotes an output intensity saturated amplification modulator, reference numeral 33 denotes an amplification modulation section, and reference numeral 34 denotes an emission port. 8, the input light is subjected to saturation amplification and attenuation by an input signal from a control terminal (not shown) in an amplification modulation section 33. The output light that has been amplified and modulated by the saturation amplification and attenuation is output from the output port 34. In this way, it is possible to modulate with the input signal by the saturation amplification and attenuation.
増幅器としての増幅度は増幅変調部に設けられた電極への入力信 号電流の大小によって決定される。 入力信号電流を大きくすると、 増幅度も大きくなる。 また、 入力光に対して出力光の強度が飽和す る飽和点も同時に大きくなる。 入力信号電流を小さくすると入力光 の増幅度が小さく、 あるいは減衰することになる。 入力信号電流に よって光位相を変調すると位相変調、 又は光周波数を変調すると周 波数変調することになる。 ここで、 飽和増幅され、 変調された出力 光の波長は、 出力強度飽和型増幅変調器への入力光の波長と同じで ある。  The degree of amplification as an amplifier is determined by the magnitude of the input signal current to the electrodes provided in the amplification modulation section. Increasing the input signal current increases the amplification. In addition, the saturation point at which the intensity of the output light is saturated with respect to the input light also increases at the same time. When the input signal current is reduced, the amplification degree of the input light is reduced or attenuated. When the optical phase is modulated by the input signal current, phase modulation is performed, or when the optical frequency is modulated, frequency modulation is performed. Here, the wavelength of the output light that has been subjected to saturation amplification and modulation is the same as the wavelength of the input light to the output intensity saturation type amplification modulator.
他の出力強度飽和型増幅変調器の概略構造を図 9に示す。 前述の 出力強度飽和型増幅変調器は、 1 の電極で飽和増幅と変調を行った 。 本出力強度飽和型増幅変調器は飽和増幅部と変調部を分離したも のである。 従って、 制御端子も増幅制御端子と変調入力端子に分離 する。  FIG. 9 shows a schematic structure of another output intensity saturated amplification modulator. The output intensity saturation amplification modulator described above performed saturation amplification and modulation with one electrode. This output intensity-saturated amplification modulator separates the saturation amplification section from the modulation section. Therefore, the control terminal is also separated into an amplification control terminal and a modulation input terminal.
図 9において、 3 2は出力強度飽和型増幅変調器、 3 5は増幅部 、 3 6は変調部、 3 4は出射口である。 図 9 において、 入力光に対 して、 増幅制御端子 (図示せず) からの制御入力信号により増幅部 3 5で飽和増幅を行い、 変調部 3 6で変調入力端子 (図示せず) か らの変調入力信号により変調を行う。 増幅変調された出力光は出射 口 3 4から出力される。 このように、 増幅部と変調部を分離するこ とにより、 それぞれ独立に増幅作用と変調作用を行うことができる 増幅器としての増幅度は増幅部に設けられた電極への制御入力信 号電流の大小によって決定される。 制御入力信号電流を大きくする と、 増幅度も大きくなる。 また、 入力光に対して出力光の強度が飽 和する飽和点も同時に大きくなる。 増幅部を複数に分割し、 前段部 では増幅度を大きく、 後段部では増幅度を小さくすることによって 、 効率的に飽和増幅することもできる。 変調部では、 変調入力信号 電流によって、 出力光を増幅又は減衰して強度変調する。 変調入力 信号電流によって光位相を変調すると位相変調、 又は光周波数を変 調すると周波数変調することになる。 ここで、 飽和増幅され、 変調 された出力光の波長は、 出力強度飽和型増幅変調器への入力光の波 長と同じである。 In FIG. 9, reference numeral 32 denotes an output intensity saturated amplification modulator, reference numeral 35 denotes an amplification unit, reference numeral 36 denotes a modulation unit, and reference numeral 34 denotes an output port. In FIG. 9, for the input light, the amplification section 35 performs saturation amplification by a control input signal from an amplification control terminal (not shown), and the modulation section 36 performs modulation amplification on a modulation input terminal (not shown). Modulation is performed by these modulation input signals. The output light that has been amplified and modulated is output from the output port 34. In this way, by separating the amplifying section and the modulating section, the amplifying and modulating actions can be performed independently of each other. The amplification degree of the amplifier is controlled by the control input signal current to the electrodes provided in the amplifying section. Determined by the size. Increasing the control input signal current increases the amplification. In addition, the saturation point at which the intensity of the output light saturates the input light also increases. By dividing the amplifying unit into a plurality of parts and increasing the degree of amplification in the first stage and decreasing the degree of amplification in the second stage, saturation amplification can be performed efficiently. The modulation section amplifies or attenuates the output light by the modulation input signal current to modulate the intensity. Modulation input Modulation of the optical phase by the signal current results in phase modulation, or modulation of the optical frequency results in frequency modulation. Here, the wavelength of the output light that has been saturated amplified and modulated is the same as the wavelength of the input light to the output intensity saturated amplification modulator.
従って、 出力強度飽和型増幅変調器 3 1又は 3 2 を実施の形態で 説明する従装置の光送受信装置に適用すると、 上り光信号の波長を 下り光信号の波長に追随させることができ、 従装置での上り光信号 の波長を高精度に制御したり、 維持したりすることを不要とするこ とができた。  Therefore, if the output intensity saturated amplification modulator 31 or 32 is applied to the optical transceiver of the slave device described in the embodiment, the wavelength of the upstream optical signal can be made to follow the wavelength of the downstream optical signal. This eliminates the need to precisely control and maintain the wavelength of the upstream optical signal in the equipment.
(実施の形態 7 )  (Embodiment 7)
反射膜付き出力強度飽和型増幅変調器を備える光送受信装置につ いて説明する。 通常の半導体光増幅器は、 入力光に対して出力光が 線形増幅される領域を使用して光増幅する。 さらに、 入射端面の入 射口から入射した光信号を増幅して、 入射端面と対向する出射端面 の出射口から出射する。 一方、 反射膜付き出力強度飽和型増幅変調 器は、 半導体光増幅器において入力光に対して出力光の強度が飽和 増幅する領域を積極的に利用し、 かつ変調も行うようにしたもので ある。 さらに、 入射端面と対向する端面に劈開状態に比べて高反射 率を有する膜をコーティ ングし、 入射端面の入射口から入射した光 信号を飽和増幅、 減衰させて、 コーテイダした反射膜で反射させた 後、 前記下り光信号の入射端面から送出する反射型構成である。 An optical transmission / reception device including an output intensity saturated amplification modulator with a reflection film will be described. An ordinary semiconductor optical amplifier performs optical amplification using a region where output light is linearly amplified with respect to input light. Further, the optical signal incident from the entrance of the incident end face is amplified and emitted from the exit of the exit end face facing the incident end face. On the other hand, the output-intensity-saturation-type modulator with a reflection film is a semiconductor optical amplifier in which the region where the intensity of the output light saturates and amplifies with respect to the input light is positively used and modulation is performed. In addition, the end face facing the incident end face has higher reflection than the cleavage state. A reflection type configuration in which a film having a refractive index is coated, an optical signal incident from the entrance of the entrance end face is saturated and attenuated, attenuated, reflected by the coated reflective film, and transmitted from the entrance end face of the downstream optical signal. It is.
反射膜付き出力強度飽和型増幅変調器の概略断面を図 1 0 に示す 。 図 1 0において、 3 3は増幅変調部、 3 7は反射膜付き出力強度 飽和型増幅変調器、 3 9は入出射口、 4 0は反射膜である。  FIG. 10 shows a schematic cross section of an output intensity saturated amplification modulator with a reflection film. In FIG. 10, 33 is an amplification modulation section, 37 is an output intensity saturated amplification modulator with a reflection film, 39 is an input / output port, and 40 is a reflection film.
図 1 0において、 入出射口 3 9からの入射光に対して、 増幅変調 部 3 3で入力信号により飽和増幅と減衰を行う。 飽和増幅と減衰に より、 増幅変調された光信号は反射膜 4 0で反射されて、 入出射口 3 9から出射する。 出射した光信号は入射光を飽和増幅、 減衰させ るため、 その波長は入射光と同じである。 増幅器としての増幅度は 増幅変調部に設けられた電極への入力信号電流の大小によって決定 される。 入力信号電流を大きくすると、 増幅度も大きくなる。 また 、 入力光に対して出力光の強度が飽和する飽和点も同時に大きくな る。 入力信号電流を小さくすると入力光の増幅度が小さく、 あるい は減衰することになる。 入力信号電流によって光位相を変調すると 位相変調、 又は光周波数を変調すると周波数変調することになる。  In FIG. 10, the amplification and modulation section 33 performs saturation amplification and attenuation on the incident light from the input / output port 39 by the input signal. The optical signal amplified and modulated by the saturation amplification and the attenuation is reflected by the reflection film 40 and emitted from the input / output port 39. The emitted optical signal saturates and attenuates the incident light, and its wavelength is the same as that of the incident light. The degree of amplification as an amplifier is determined by the magnitude of the input signal current to the electrodes provided in the amplification modulation section. Increasing the input signal current increases the amplification. Further, the saturation point at which the intensity of the output light is saturated with respect to the input light also increases at the same time. When the input signal current is reduced, the amplification degree of the input light is reduced or attenuated. When the optical phase is modulated by the input signal current, phase modulation is performed, or when the optical frequency is modulated, frequency modulation is performed.
他の反射膜付き出力強度飽和型増幅変調器の概略断面を図 1 1 に 示す。 前述の出力強度飽和型増幅変調器は、 1 の電極で飽和増幅と 変調を行った。 本出力強度飽和型増幅変調器は飽和増幅部と変調部 を分離したものである。 従って、 制御端子も増幅制御端子と変調入 力端子に分離する。 図 1 1 において、 3 5は増幅部、 3 6は変調部 、 3 8は反射膜付き出力強度飽和型増幅変調器、 3 9は入出射口、 4 0は反射膜である。  Fig. 11 shows a schematic cross section of another output intensity-saturated amplification modulator with a reflection film. The output intensity saturation-type amplification modulator described above performed saturation amplification and modulation with one electrode. This output intensity-saturated amplification modulator is one in which the saturation amplification section and the modulation section are separated. Therefore, the control terminal is also separated into an amplification control terminal and a modulation input terminal. In FIG. 11, reference numeral 35 denotes an amplifying unit, 36 denotes a modulating unit, 38 denotes an output intensity saturation type amplifying modulator with a reflective film, 39 denotes an input / output port, and 40 denotes a reflective film.
図 1 1 において、 入出射口 3 9からの入射光に対して、 増幅制御 端子 (図示せず) からの制御入力信号により増幅部 3 5で飽和増幅 を行い、 変調部 3 6で変調入力端子 (図示せず) からの変調入力信 号により変調を行う。 飽和増幅と減衰により、 増幅変調された光信 号は反射膜 4 0で反射されて、 入出射口 3 9から出射する。 出射し た光信号は入射光を飽和増幅、 減衰させるため、 その波長は入射光 と同じである。 In FIG. 11, the amplification section 35 performs saturation amplification on the incident light from the input / output port 39 by a control input signal from an amplification control terminal (not shown), and modulates the modulation input terminal by a modulation section 36. Modulation is performed using a modulation input signal from a (not shown). The optical signal amplified and modulated by the saturation amplification and attenuation is reflected by the reflection film 40 and emitted from the input / output port 39. Outgoing The wavelength of the optical signal is the same as that of the incident light because the incident light is saturated and amplified and attenuated.
増幅器としての増幅度は増幅部に設けられた電極への制御入力信 号電流の大小によって決定される。 制御入力信号電流を大きくする と、 増幅度も大きくなる。 また、 入力光に対して出力光の強度が飽 和する飽和点も同時に大きくなる。 増幅部を複数に分割し、 前段部 では増幅度を大きく、 後段部では増幅度を小さくすることによって 、 効率的に飽和増幅することもできる。 変調部では、 変調入力信号 電流によって、 出力光を増幅又は減衰して強度変調する。 変調入力 信号電流によって光位相を変調すると位相変調、 又は光周波数を変 調すると周波数変調することになる。  The degree of amplification as an amplifier is determined by the magnitude of the control input signal current to the electrodes provided in the amplifier. Increasing the control input signal current increases the amplification. In addition, the saturation point at which the intensity of the output light saturates the input light also increases. By dividing the amplifying unit into a plurality of parts and increasing the degree of amplification in the first stage and decreasing the degree of amplification in the second stage, saturation amplification can be performed efficiently. The modulation section amplifies or attenuates the output light by the modulation input signal current to modulate the intensity. Modulation input Modulation of the optical phase by the signal current results in phase modulation, or modulation of the optical frequency results in frequency modulation.
従って、 反射膜付き出力強度飽和型増幅変調器 3 7又は 3 8を、 従装置の光送受信装置、 特に、 実施の形態で説明する下り光信号の 伝送と上り光信号の伝送に同じ光ファイバを使用する双方向光伝送 方式に利用する従装置の光送受信装置に適用すると、 上り光信号の 波長を下り光信号の波長に追随させることができ、 従装置での上り 光信号の波長を高精度に制御したり、 維持したりすることを不要と することができた。  Therefore, the output-intensity-saturation-type amplifying modulator 37 or 38 with the reflection film is connected to the optical transmitting / receiving device of the slave device, particularly, the same optical fiber for transmission of the downstream optical signal and transmission of the upstream optical signal described in the embodiment. When applied to the optical transceiver of the slave device used for the bidirectional optical transmission system to be used, the wavelength of the upstream optical signal can be made to follow the wavelength of the downstream optical signal, and the wavelength of the upstream optical signal in the slave device can be accurately determined. It is no longer necessary to control or maintain the same.
(実施の形態 8 )  (Embodiment 8)
本実施の形態は、 反射膜付き出力強度飽和型増幅変調器を備える 光送受信装置及び前記光送受信装置を利用した双方向光伝送方式で ある。 反射膜付き出力強度飽和型増幅変調器を備える光送受信装置 の構成を図 1 2に示す。 図 1 2において、 1 5は光ファイバ、 1 7 は従装置の光合分岐回路、 1 8は従装置の光受信回路、 1 9従装置 の光送信回路、 2 2は光受信部、 2 3は駆動部、 3 7は反射膜付き 出力強度飽和型増幅変調器である。  The present embodiment relates to an optical transmitting / receiving device including an output intensity saturated amplification modulator with a reflection film, and a bidirectional optical transmission system using the optical transmitting / receiving device. Fig. 12 shows the configuration of an optical transmitting and receiving device equipped with an output intensity saturation type amplification modulator with a reflection film. In FIG. 12, 15 is an optical fiber, 17 is an optical coupling / branching circuit of a slave device, 18 is an optical receiving circuit of a slave device, 19 is an optical transmitting circuit of a slave device, 22 is an optical receiving unit, and 23 is an optical receiving unit. The driving unit 37 is an output intensity saturated type amplification modulator with a reflection film.
図 1 2において、 光ファイバ 1 5 を伝搬してきた下り光信号は、 光合分岐回路 1 7 によって、 一部は光受信回路 1 8 の光受信部で受 信される。 光合分岐回路 1 7で分岐された他の下り光信号は、 反射 膜付き出力強度飽和型増幅変調器 3 7 に入射し、 飽和増幅、 変調さ れた後、 光合分岐回路 1 7に戻る。 戻った光信号は、 上りの光信号 として光ファイバ 1 5を伝搬する。 戻った光信号の波長は下り光信 号の波長と同じである。 ここで、 反射膜付き出力強度飽和型増幅変 調器 3 7を反射膜付き出力強度飽和型増幅変調器 3 8に置き換えて も同様の効果が得られる。 In FIG. 12, a downstream optical signal transmitted through the optical fiber 15 is partially received by the optical multiplexing / branching circuit 17 and is received by the optical receiving unit of the optical receiving circuit 18. The other downstream optical signals branched by the optical coupler 17 are reflected. The light enters the output-saturation-amplified modulator 37 with a film, and is subjected to saturation amplification and modulation. The returned optical signal propagates through the optical fiber 15 as an upstream optical signal. The wavelength of the returned optical signal is the same as the wavelength of the downstream optical signal. Here, the same effect can be obtained by replacing the output intensity saturated amplification modulator 37 with a reflection film with the output intensity saturation amplification modulator 38 with a reflection film.
反射膜付き出力強度飽和型増幅変調器は、 入射口と出射口が共通 であるために、 実施の形態で説明する下り光信号の伝送と上り光信 号の伝送に同じ光ファイバを使用する双方向光伝送方式に有効であ る。 反射膜付き出力強度飽和型増幅変調器をこれらの伝送方式に適 用すると、 図 1 2 と図 4 ( b ) とを比較すれば明らかなように、 本 実施の形態を示す図 1 2では図 4 ( b ) の光分岐回路 2 1が不要と なる。 このため、 分岐に伴う光損失も減少する。  The output intensity saturated amplifier with reflection film has a common input port and output port, so that the same optical fiber is used for transmission of the downstream optical signal and transmission of the upstream optical signal described in the embodiment. Effective for optical transmission systems. When an output intensity saturated type amplifying modulator with a reflection film is applied to these transmission systems, it is clear from a comparison between FIG. 12 and FIG. 4 (b) that FIG. 12 shows the present embodiment. The optical branch circuit 21 of 4 (b) becomes unnecessary. For this reason, optical loss due to branching is also reduced.
従って、 本反射膜付き出力強度飽和型増幅変調器を、 従装置の光 送受信装置、 特に、 実施の形態で説明する下り光信号の伝送と上り 光信号の伝送に同じ光ファイバを使用する双方向光伝送方式に利用 する従装置の光送受信装置に適用すると、 上り光信号の波長を下り 光信号の波長に追随させることができ、 従装置での上り光信号の波 長を高精度に制御したり、 維持したりすることを不要とすることが できた。 さらに、 1芯光ファイバ方向多重双方向伝送や 1芯光ファ ィバ双方向一波長多重マルチボイント伝送方式においては、 光分岐 回路の削減と光損失の減少を可能とすることができた。  Therefore, the output intensity saturated amplification modulator with the reflection film is used as a slave optical transmission / reception device, in particular, a bidirectional transmission using the same optical fiber for transmission of the downstream optical signal and transmission of the upstream optical signal described in the embodiment. When applied to the optical transceiver of the slave device used in the optical transmission system, the wavelength of the upstream optical signal can be made to follow the wavelength of the downstream optical signal, and the wavelength of the upstream optical signal in the slave device can be controlled with high precision. And maintenance was no longer necessary. Furthermore, in single-core optical fiber direction multiplex bidirectional transmission and single-core optical fiber bidirectional single-wavelength multiplex multipoint transmission systems, it was possible to reduce the number of optical branch circuits and reduce optical loss.
(実施の形態 9 )  (Embodiment 9)
飽和増幅部及び変調部を有する出力強度飽和型増幅変調器を備え る光送受信装置について説明する。 飽和増幅部としては、 入力光に 対して出力光の強度が飽和増幅する領域を用いる半導体光増幅を利 用する。 変調部としては、 小型低電圧で駆動できる半導体吸収型変 調を利用する。 吸収型変調は高速の変調が可能である。  An optical transmission / reception device including an output intensity saturation amplification modulator having a saturation amplification unit and a modulation unit will be described. As the saturation amplifying unit, semiconductor optical amplification using a region where the intensity of the output light is saturated and amplified with respect to the input light is used. The modulator uses a semiconductor absorption type modulator that can be driven with a small and low voltage. Absorption type modulation enables high-speed modulation.
出力強度飽和型増幅変調器の概略構造を図 1 3に示す。 図 1 3 に おいて、 6 1 は飽和増幅部及び変調部を有する出力強度飽和型増幅 変調器、 6 2は飽和増幅部、 6 3は変調部、 6 4は半導体光増幅を 実現する半導体活性層、 6 5は変調を実現する吸収変調層である。 Fig. 13 shows the schematic structure of the output intensity saturated amplification modulator. Figure 13 Here, 61 is an output intensity saturation type modulator having a saturation amplification section and a modulation section, 62 is a saturation amplification section, 63 is a modulation section, 64 is a semiconductor active layer for realizing semiconductor optical amplification, and 65 is a semiconductor active layer. Is an absorption modulation layer for realizing modulation.
図 1 3において、 入力光に対して飽和増幅部 6 2で入力信号の飽 和増幅を行い、 バイアス成分が増幅されるとともに信号成分が圧縮 され、 さらに、 変調部 6 3において変調される。 変調部 6 3は吸収 型変調を実現し、 活性層のキャリアライフタイムに制限されないた め、 高速変調が可能である。 本変調部では、 吸収端が使用する波長 に比べ短波長側に設定されているため、 変調効率は入力光の波長に 依存しない。 /  In FIG. 13, the input signal is subjected to saturation amplification of the input signal in the saturation amplifier 62, the bias component is amplified, the signal component is compressed, and the signal is modulated in the modulator 63. The modulator 63 realizes absorption type modulation and is not limited by the carrier lifetime of the active layer, so that high-speed modulation is possible. In this modulator, the modulation efficiency does not depend on the wavelength of the input light because the absorption edge is set to a shorter wavelength than the wavelength used. /
従って、 出力強度飽和型増幅変調器 6 1-を実施の形態で説明する 従装置の光送受信装置に適用すると、 上り光信号の波長を下り光信 号の波長に追随させることができ、 従装置での上り光信号の波長を 高精度に制御したり、 維持したりすることを不要とすることができ た。  Therefore, when the output intensity saturated amplification modulator 61- is applied to the optical transceiver of the slave device described in the embodiment, the wavelength of the upstream optical signal can be made to follow the wavelength of the downstream optical signal. It was not necessary to control or maintain the wavelength of the upstream optical signal with high precision.
(実施の形態 1 0 )  (Embodiment 10)
本実施の形態は、 主装置と複数の従装置で 2芯.光フアイバ双方向 • 波長時分割多重マルチポイント伝送する双方向光伝送方式である 。 本発明の実施の形態の構成を図 1 4に示す。 図 1 4において、 2 5は主装置の光送信回路、 2 6は主装置の光受信回路、 1 5 — 1 、 1 5 — 2は光ファイバ、 1 6 — 1、 1 6— 2は光ファイバの途中に 設けられた波長多重回路、 1 8— :!〜 1 8 — Nは従装置の光受信回 路、 1 9 — 1〜 1 9 一 Nは従装置の光送信回路である。 ここでは、 2以上の複数を表すときに記号 Nを用いた。 例えば、 光送信回路 1 1 一 :!〜 1 1 — Nは 2以上の複数の光送信回路を表す。 図 1 4にお いて、 下方向の矢印は下り、 上方向の矢印は上りの伝送方向を表す 主装置と複数の従装置で双方向伝送する方式の構成について説明 する。 図 1 4において、 主装置の光送信回路 2 5は下り信号で変調 した信号成分にバイアス成分を重畳したそれぞれの下り光信号を従 装置に向けて送信する。 その際、 主装置の光送信回路 2 5において 、 その中に有する波長可変光源の波長は、 外部の制御信号によって N個の波長 ( λ ェ〜 λ N ) のいずれかが割り当てられる。 割り当て られる波長は、 従装置の光受信回路 1 8 — Nに送信する光信号は λThe present embodiment is a bi-directional optical transmission system in which a main unit and a plurality of slave units have two cores. FIG. 14 shows the configuration of the embodiment of the present invention. In Fig. 14, 25 is the optical transmission circuit of the main unit, 26 is the optical receiving circuit of the main unit, 15-1 and 15-2 are optical fibers, 16-1 and 16-2 are optical fibers Wavelength division multiplexing circuit provided in the middle of 1 18 —N is the optical receiving circuit of the slave, and 19 1 1 to 19 NN is the optical transmitting circuit of the slave. Here, the symbol N is used to represent two or more. For example, optical transmission circuit 1 1 1:! 1 1 1 —N represents two or more optical transmission circuits. In FIG. 14, the configuration of a system for performing bidirectional transmission between a main device and a plurality of slave devices, in which a downward arrow indicates a downward direction and an upward arrow indicates an upward transmission direction, will be described. In Fig. 14, the optical transmission circuit 25 of the main unit is modulated with a downstream signal. The respective downstream optical signals obtained by superimposing the bias components on the signal components thus transmitted are transmitted to the slave devices. At this time, in the optical transmission circuit 25 of the main device, any one of N wavelengths (λ to λ N ) is assigned to the wavelength of the wavelength variable light source included therein by an external control signal. The assigned wavelength is λ for the optical signal transmitted to the optical receiver circuit 18 — N of the slave device.
Νの波長である。 つまり、 主装置の光送信回路 2 5は、 従装置ごと に異なる時間領域と波長で光信号を送信する。 波長 wavelength. That is, the optical transmission circuit 25 of the main device transmits an optical signal in a different time domain and wavelength for each slave device.
光ファイバ 1 5 — 1 の途中に設けられた波長多重回路 1 6 — 1 は 、 それぞれの下り光信号を波長に応じてそれぞれの従装置に向けて 波長分離する。 それぞれの従装置の光受信回路 1 8 — 1 〜 1 8 — Ν は光ファイバ 1 5 — 1 を通して受信した下り光信号から信号成分を 検出する。 それぞれの従装置の光送信回路 1 9 — 1 〜 1 9— Νは受 信した下り光信号の一部を飽和増幅 · 減衰回路によって上り信号で 変調した上り光信号を光ファイバ 1 5 — 2に向けて送信する。 従装 置の光送信回路の出力強度飽和型増幅変調器で下り光信号を飽和増 幅するため、 送信する波長は下り光信号と同じである。 光ファイバ 1 5 — 2の途中に設けられた波長多重回路 1 6 — 2は複数の光送信 回路 1 9 一 :! 〜 1 9— Νから送信された、 異なる波長 ( A i〜 A N ) の上り光信号を主装置に向けて波長多重する。 主装置の光受信回 路 2 6は受信した上り光信号から上り信号を検出する。 The wavelength multiplexing circuit 16-1 provided in the middle of the optical fiber 15-1 separates each downstream optical signal toward each slave device according to the wavelength. The optical receiving circuits 18-1 to 18-Ν of each slave device detect a signal component from the downstream optical signal received through the optical fiber 15-1. The optical transmission circuit 19-1 to 19-の of each slave device transmits an upstream optical signal, which is obtained by modulating a part of the received downstream optical signal with an upstream signal by a saturation amplification / attenuation circuit, to an optical fiber 15-2. Send to. The wavelength to be transmitted is the same as that of the downstream optical signal because the downstream optical signal is saturated and amplified by the output intensity saturation type amplification modulator of the optical transmission circuit of the slave unit. The wavelength division multiplexing circuit 16-2 provided in the middle of the optical fiber 15-2 is a plurality of optical transmission circuits 19-1 :! 1 1 9 — Wavelength multiplexes upstream optical signals of different wavelengths (A i to A N ) transmitted from Ν toward the main unit. The optical receiving circuit 26 of the main device detects an upstream signal from the received upstream optical signal.
次に、 本構成での動作を説明する。 下り信号の送信には、 従装置 の受信回路に送信する信号ごとに時間領域を分離する。 さらに、 従 装置の受信回路に送信する信号ごとに波長可変レーザの波長を変え る。 例えば、 従装置の受信回路 1 8 — 1 に送信するときは、 波長 λ ェでかつ時間領域が t ェで下り光信号を送信する。 下り信号で光を 変調する動作は図 2 と同様である。 時間領域はダイムスロッ トごと に受信する従装置の受信回路を変えてもよいし、 一定の長さの情報 をまとめたブロックごとでもよい。 所定の従装置の受信回路に送信 する光信号の時間領域と他の従装置の受信回路に送信する光信号の 時間領域の間隔は複数の従装置との距離に応じて予め調整してもよ いし、 一定間隔を空けておく ことでもよい。 波長 · 時分割多重され た光信号は、 波長多重回路 1 6— 1で従装置ごとに分離され、 従装 置の光受信回路 1 8 — :! 〜 1 8— Nで受信される。 光受信回路 1 8 一 :!〜 1 8 — Nでの下り信号の受信動作は図 2 ( d ) と同様である 。 光受信回路 1 8 — 1 〜 1 8 — Nでは波長ごと、 換言すると時間領 域ごとに分離された光信号を受信する。 Next, the operation in this configuration will be described. For transmission of the downlink signal, the time domain is separated for each signal transmitted to the reception circuit of the slave device. Furthermore, the wavelength of the tunable laser is changed for each signal transmitted to the receiving circuit of the slave device. For example, when transmitting to the receiving circuit 18-1 of the slave device, the downstream optical signal is transmitted with the wavelength λ and the time domain t. The operation of modulating the light with the downstream signal is the same as in Fig. 2. In the time domain, the receiving circuit of the slave device that receives data may be changed for each dime slot, or may be for each block in which information of a fixed length is collected. The time domain of the optical signal transmitted to the receiving circuit of a given slave device and the time domain of the optical signal transmitted to the receiving circuit of another slave device The interval of the time domain may be adjusted in advance according to the distance to a plurality of slave devices, or may be set at a fixed interval. The wavelength- and time-division multiplexed optical signal is separated for each slave device by a wavelength multiplexing circuit 16-1, and the optical receiver circuit 18 for the slave device 18 ::! ~ 18-received by N. Optical receiving circuit 1 8 1:! The receiving operation of the downlink signal at ~ 18-N is the same as that in Fig. 2 (d). Optical receiving circuit 18-1 to 18-N receives optical signals separated for each wavelength, in other words, for each time domain.
上り信号の送信動作は図 3 に示す飽和増幅及び変調動作と同様で あるが、 送信光信号は、 各従装置に下り光信号が到達しているとき に、 上り光信号を送信する。 各従装置からの上り光信号は波長多重 回路 1 6— 2で多重され、 主装置の光受信回路 2 6で受信される。 光受信回路 2 6で受信する際に、 各従装置からの上り光信号が重な らないように、 主装置から従装置へ向けて送信する際に時間領域の 間隔が設定されている。 下り光信号と上り光信号は別の光ファイバ を用いて伝送される。 このように動作して、 2芯光ファイバ双方向 • 波長時分割多重マルチボイント伝送が行われる。  The transmission operation of the upstream signal is the same as the saturation amplification and modulation operation shown in FIG. 3, but the transmission optical signal transmits the upstream optical signal when the downstream optical signal reaches each slave device. The upstream optical signal from each slave device is multiplexed by the wavelength multiplexing circuit 16-2 and received by the optical receiving circuit 26 of the master device. The time domain interval is set when transmitting from the master device to the slave device so that the upstream optical signals from the slave devices do not overlap when receiving by the optical receiving circuit 26. The downstream optical signal and the upstream optical signal are transmitted using different optical fibers. By operating in this manner, two-core optical fiber bidirectional • wavelength time division multiplex multipoint transmission is performed.
なお、 主装置において、 光受信回路 2 5 に代えて、 図 5のように 、 主装置の波長多重回路 1 3 - 2 と複数の主装置の光受信回路 1 2 — 1 〜 1 2 _ Nとしてもよい。 このような構成にすると、 主装置か ら各従装置までの距離差に係らず、 各従装置からの上り光信号が重 ならないように、 所定の従装置の受信回路に送信する光信号の時間 領域と他の従装置の受信回路に送信する光信号の時間領域の間隔を 設定する必要がなくなる。  In the main apparatus, instead of the optical receiving circuit 25, as shown in FIG. 5, a wavelength multiplexing circuit 13-2 of the main apparatus and optical receiving circuits 12-1 to 12_N of a plurality of main apparatuses are used. Is also good. With such a configuration, the time of the optical signal transmitted to the receiving circuit of a given slave device is determined so that the upstream optical signals from each slave device do not overlap regardless of the distance difference from the master device to each slave device. It is not necessary to set the interval between the region and the time region of the optical signal transmitted to the receiving circuit of another slave device.
ここで、 各時間領域に割り当てられる波長は、 A i A wのすベ てを割り当てる必要はなく、 各従装置へ送信する情報量に応じて変 えることもできる。 さらに、 時間領域の長さも各従装置に対して一 定ではなく、 各従装置へ送信する情報量に応じて変えることもでき る。  Here, it is not necessary to assign all of A i A w to the wavelength assigned to each time domain, and it can be changed according to the amount of information transmitted to each slave device. Furthermore, the length of the time domain is not fixed for each slave device, but can be changed according to the amount of information transmitted to each slave device.
従って、 主装置の光送信回路が下り信号で変調した信号成分にバ ィァス成分を重畳した下り光信号を光ファイバに送信し、 従装置の 光送信回路が受信した下り光信号の一部を飽和増幅 · 減衰回路によ つて上り信号で変調した上り光信号を光ファイバに送信する構成と することにより、 従装置側では、 発光素子を使用することなく、 双 方向伝送をすることができた。 Therefore, the optical transmission circuit of the main unit covers the signal component modulated by the downlink signal. The downstream optical signal with the bias component superimposed is transmitted to the optical fiber, and the upstream optical signal obtained by modulating a part of the downstream optical signal received by the optical transmission circuit of the slave device with the upstream signal by the saturation amplification / attenuation circuit is output to the optical fiber. Thus, the slave device can perform bidirectional transmission without using a light emitting element.
また、 従装置の光送信回路は出力強度飽和型増幅変調器によって 、 下り光信号と同じ波長の上り光信号を送信するため、 波長多重回 路に対して、 上り光信号の波長を高精度に制御したり、 維持したり する必要はなくなつた。  In addition, the optical transmission circuit of the slave device transmits the upstream optical signal having the same wavelength as the downstream optical signal by the output intensity saturation type amplifying modulator, so that the wavelength of the upstream optical signal can be accurately determined with respect to the wavelength multiplexing circuit. You no longer need to control or maintain.
さらに、 本従装置の光送信回路において、 半導体光増幅器の出力 強度飽和増幅機能を広範囲の波長にわたって動作させると、 波長ご とに従装置の種類が異なるのではなく、 同一種の従装置を任意の従 装置に適用することができる。 即ち、 従装置間で、 相互運用性 (ィ ン夕オペラピリティ) を確保することが可能となった。  Furthermore, when the output intensity saturation amplification function of the semiconductor optical amplifier is operated over a wide range of wavelengths in the optical transmission circuit of the slave device, the type of slave device is not different for each wavelength, but the same type of slave device is optional. The present invention can be applied to a slave device. In other words, interoperability (interoperability) between slave devices has become possible.
(実施の形態 1 1 )  (Embodiment 11)
本実施の形態は、 主装置と複数の従装置で 1芯光ファイバ双方向 In the present embodiment, a single-core optical fiber bidirectional
• 波長時分割多重マルチポイント伝送する双方向光伝送方式である• It is a bidirectional optical transmission system for wavelength time division multiplex multipoint transmission
。 本発明の実施の形態の構成を図 1 5に示す。 図 1 5において、 2 5は主装置の光送信回路、 2 6は主装置の光受信回路、 1 5— 1、 1 5— 2は光ファイノ、、 1 6 — 1、 1 6 — 2は光ファイバの途中に 設けられた波長多重回路、 1 8 _ 1〜 1 8— 0ま従装置の光受信回 路、 1 9 _ 1〜 1 9 — Nは従装置の光送信回路である。 ここでは、 2以上の複数を表すときに記号 Nを用いた。 例えば、 光送信回路 1 1 — 1〜 1 l _ Nは 2以上の複数の光送信回路を表す。 図 1 5にお いて、 下方向の矢印は下り、 上方向の矢印は上りの伝送方向を表す 主装置と複数の従装置で双方向伝送する方式の構成について説明 する。 図 1 5において、 主装置の光送信回路 2 5は下り信号で変調 した信号成分にバイアス成分を重畳したそれぞれの下り光信号を従 装置に向けて送信する。 その際、 主装置の光送信回路 2 5において 、 その中に有する波長可変光源の波長は、 外部の制御信号によって. FIG. 15 shows the configuration of the embodiment of the present invention. In Fig. 15, 25 is the optical transmission circuit of the main unit, 26 is the optical receiving circuit of the main unit, 15-1, 15-2 is the optical finos, 16-1, and 16-2 are the optical The wavelength multiplexing circuit provided in the middle of the fiber, 18_1 to 18-0, is the optical receiving circuit of the slave device, and 19_1 to 19-N is the optical transmitting circuit of the slave device. Here, the symbol N is used to represent two or more. For example, the optical transmission circuit 11-1 to 1 l_N represents two or more optical transmission circuits. In FIG. 15, a configuration of a method of performing bidirectional transmission between a main device and a plurality of slave devices, in which a downward arrow indicates a downward transmission direction and an upward arrow indicates an upward transmission direction, will be described. In FIG. 15, the optical transmission circuit 25 of the main unit follows each downstream optical signal obtained by superimposing a bias component on a signal component modulated by the downstream signal. Send to device. At that time, in the optical transmission circuit 25 of the main device, the wavelength of the tunable light source included therein is controlled by an external control signal.
N個の波長 ( λ ェ〜 λ N ) のいずれかが割り当てられる。 割り当て られる波長は、 従装置の光受信回路 1 8 — Nに送信する光信号は λ Νの波長である。 つまり、 主装置の光送信回路 2 5は、 従装置ごと に異なる時間領域と波長で光信号を送信する。 One of the N wavelengths (λ to λ N ) is assigned. The wavelength to be allocated is such that the optical signal transmitted to the optical receiving circuit 18-N of the slave device has a wavelength of λΝ. That is, the optical transmission circuit 25 of the main device transmits an optical signal in a different time domain and wavelength for each slave device.
光ファイバ 1 5の途中に設けられた波長多重回路 1 6は、 それぞ れの下り光信号を波長に応じてそれぞれの従装置に向けて波長分離 する。 それぞれの従装置の光受信回路 1 8— 1 〜 1 8 — Νは光ファ ィバ 1 5— 1 を通して受信した下り光信号から信号成分を検出する 。 それぞれの従装置の光送信回路 1 9 一 :!〜 1 9 — Νは受信した下 り光信号の一部を飽和増幅 · 減衰回路によって上り信号で変調した 上り光信号を光ファイバ 1 5 に向けて送信する。 従装置の光送信回 路の出力強度飽和型増幅変調器で下り光信号を飽和増幅するため、 送信する波長は下り光信号と同じである。 光ファイバ 1 5の途中に 設けられた波長多重回路 1 6は複数の光送信回路 1 9 一 :!〜 1 9 一 Νから送信された、 異なる波長 ( ェ〜 !^ ) の上り光信号を主装 置に向けて波長多重する。 主装置の光受信回路 2 6は受信した上り 光信号から上り信号を検出する。  The wavelength multiplexing circuit 16 provided in the middle of the optical fiber 15 separates the wavelength of each downstream optical signal toward each slave device according to the wavelength. The optical receiving circuits 18-1 to 18-Ν of each slave device detect a signal component from the downstream optical signal received through the optical fiber 15-1. The optical transmission circuit of each slave device 1 9 1:! 1 1 9 — Ν transmits the upstream optical signal, which is obtained by modulating a part of the received downstream optical signal with the upstream signal by the saturation amplification / attenuation circuit, to the optical fiber 15. Since the downstream optical signal is saturated and amplified by the output intensity saturation amplification modulator of the optical transmission circuit of the slave device, the wavelength to be transmitted is the same as the downstream optical signal. The wavelength division multiplexing circuit 16 provided in the middle of the optical fiber 15 is composed of a plurality of optical transmission circuits 19 1:! ~ 19 19 Wavelength multiplexing of upstream optical signals of different wavelengths (~ ^) transmitted from the receiver to the main unit. The optical receiving circuit 26 of the main device detects an upstream signal from the received upstream optical signal.
次に、 本構成での動作を説明する。 下り信号の送信には、 従装置 の受信回路に送信する信号ごとに時間領域を分離する。 さらに、 従 装置の受信回路に送信する信号ごとに波長可変レーザの波長を変え る。 例えば、 従装置の受信回路 1 8 — 1 に送信するときは、 波長 λ iでかつ時間領域が t ェで下り光信号を送信する。 下り信号で光を 変調する動作は図 2 と同様である。 時間領域はタイムスロッ トごと に受信する従装置の受信回路を変えてもよいし、 一定の長さの情報 をまとめたブロックごとでもよい。 所定の従装置の受信回路に送信 する光信号の時間領域と他の従装置の受信回路に送信する光信号の 時間領域の間隔は複数の従装置との距離に応じて予め調整してもよ いし、 一定間隔を空けておく ことでもよい。 波長 ' 時分割多重され た光信号は、 波長多重回路 1 6で従装置ごとに分離され、 従装置の 光受信回路 1 8 — 1 〜 1 8 — Nで受信される。 光受信回路 1 8 — 1 〜 1 8 — Nでの下り信号の受信動作は図 2 ( d ) と同様である。 光 受信回路 1 8 — 1 〜 1 8 — Nでは波長ごと、 換言すると時間領域ご とに分離された光信号を受信する。 Next, the operation in this configuration will be described. For transmission of the downlink signal, the time domain is separated for each signal transmitted to the reception circuit of the slave device. Furthermore, the wavelength of the tunable laser is changed for each signal transmitted to the receiving circuit of the slave device. For example, when transmitting to the receiving circuit 18-1 of the slave device, the downstream optical signal is transmitted at the wavelength λi and the time domain is t. The operation of modulating the light with the downstream signal is the same as in Fig. 2. In the time domain, the receiving circuit of the slave device for receiving may be changed for each time slot, or may be a block in which information of a fixed length is collected. The interval between the time domain of the optical signal transmitted to the reception circuit of a predetermined slave device and the time domain of the optical signal transmitted to the reception circuit of another slave device may be adjusted in advance in accordance with the distance to a plurality of slave devices. Alternatively, they may be spaced at regular intervals. The wavelength-time-division multiplexed optical signal is separated for each slave device by the wavelength multiplexing circuit 16 and received by the optical receiving circuits 18-1 to 18-N of the slave device. The receiving operation of the downlink signal in the optical receiving circuits 18-1 to 18-N is the same as that in FIG. Optical receiving circuit 18 — 1 to 18 — N receives optical signals separated by wavelength, in other words, by time domain.
上り信号の送信動作は図 3 に示す飽和増幅及び変調動作と同様で あるが、 送信光信号は、 各従装置に下り光信号が到達しているとき に、 上り光信号を送信する。 各従装置からの上り光信号は波長多重 回路 1 6で多重され、 主装置の光受信回路 2 6で受信される。 光受 信回路 2 6で受信する際に、 各従装置からの上り光信号が重ならな いように、 主装置から従装置へ向けて送信する際に時間領域の間隔 が設定されている。 下り光信号と上り光信号は同じ光ファイバを用 いて伝送される。 このように動作して、 1芯光ファイバ双方向 · 波 長時分割多重マルチポイント伝送が行われる。  The transmission operation of the upstream signal is the same as the saturation amplification and modulation operation shown in FIG. 3, but the transmission optical signal transmits the upstream optical signal when the downstream optical signal reaches each slave device. The upstream optical signal from each slave device is multiplexed by the wavelength multiplexing circuit 16 and received by the optical receiving circuit 26 of the master device. The time domain interval is set when transmitting from the master device to the slave device so that the upstream optical signals from the slave devices do not overlap when receiving by the optical receiving circuit 26. The downstream optical signal and the upstream optical signal are transmitted using the same optical fiber. By operating in this manner, single-core optical fiber bidirectional / wavelength time division multiplex multipoint transmission is performed.
なお、 主装置において、 光受信回路 2 5に代えて、 図 6のように 、 主装置の波長多重回路 1 3 — 2 と複数の主装置の光受信回路 1 2 _ 1 〜 1 2 — Nとしてもよい。 このような構成にすると、 主装置か ら各従装置までの距離差に係らず、 各従装置からの上り光信号が重 ならないように、 所定の従装置の受信回路に送信する光信号の時間 領域と他の従装置の受信回路に送信する光信号の時間領域の間隔を 設定する必要がなくなる。  In the main unit, instead of the optical receiving circuit 25, as shown in FIG. 6, a wavelength multiplexing circuit 13-2 of the main unit and optical receiving circuits 12_1 to 12-N of a plurality of main units are used. Is also good. With such a configuration, the time of the optical signal transmitted to the receiving circuit of a given slave device is determined so that the upstream optical signals from each slave device do not overlap regardless of the distance difference from the master device to each slave device. It is not necessary to set the interval between the region and the time region of the optical signal transmitted to the receiving circuit of another slave device.
ここで、 各時間領域に割り当てられる波長は、 λ 1〜 λ Νのすベ てを割り当てる必要はなく、 各従装置へ送信する情報量に応じて変 えることもできる。 さらに、 時間領域の長さも各従装置に対して一 定ではなく、 各従装置へ送信する情報量に応じて変えることもでき る。 Here, it is not necessary to assign all of the wavelengths λ 1 to λ } to the wavelengths assigned to each time domain, and they can be changed according to the amount of information transmitted to each slave device. Furthermore, the length of the time domain is not fixed for each slave device, but can be changed according to the amount of information transmitted to each slave device.
従って、 主装置の光送信回路が下り信号で変調した信号成分にバ ィァス成分を重畳した下り光信号を光ファイバに送信し、 従装置の 光送信回路が受信した下り光信号の一部を飽和増幅 · 減衰回路によ つて上り信号で変調した上り光信号を光ファイバに送信する構成と することにより、 従装置側では、 発光素子を使用することなく、 双 方向伝送をすることができた。 Therefore, the optical transmission circuit of the master device transmits the downstream optical signal in which the bias component is superimposed on the signal component modulated by the downstream signal to the optical fiber, and transmits the signal to the slave device. A light-emitting element is used on the slave device side by transmitting the upstream optical signal, which is obtained by modulating a part of the downstream optical signal received by the optical transmission circuit with the upstream signal by the saturation amplification / attenuation circuit, to the optical fiber. Bidirectional transmission could be performed without the need for communication.
また、 従装置の光送信回路は出力強度飽和型増幅変調器によって 、 下り光信号と同じ波長の上り光信号を送信するため、 波長多重回 路ゃ光合分岐回路に対して、 上り光信号の波長を高精度に制御した り、 維持したりする必要はなくなつた。  In addition, since the optical transmission circuit of the slave device transmits an upstream optical signal having the same wavelength as the downstream optical signal by the output intensity saturated amplification modulator, the wavelength of the upstream optical signal is transmitted to the wavelength multiplexing circuit / optical coupling / branching circuit. There is no longer any need to control or maintain high precision.
さらに、 本従装置の光送信回路において、 半導体光増幅器の出力 強度飽和増幅機能を広範囲の波長にわたって動作させると、 波長ご とに従装置の種類が異なるのではなく、 同一種の従装置を任意の従 装置に適用することができる。 即ち、 従装置間で、 相互運用性 (ィ ンタオペラピリティ) を確保することが可能となった。  Furthermore, when the output intensity saturation amplification function of the semiconductor optical amplifier is operated over a wide range of wavelengths in the optical transmission circuit of the slave device, the type of slave device is not different for each wavelength, but the same type of slave device is optional. The present invention can be applied to a slave device. In other words, interoperability (interoperability) can be secured between slave devices.
1芯の光ファイバで方向多重双方向 · 波長多重マルチポイント伝 送する双方向光伝送方式においては、 下り信号と上り信号が同一波 長で同一光ファイバ上を伝送される。 そのため、 主装置で上り信号 を受信する場合、 光ファイバの途中で反射した下り信号と相互干渉 する場合がある。 本実施の形態では、 発光素子の駆動電流を制御し て、 下り信号に信号成分が重畳しているため、 下り信号光のスぺク トル幅を広くすることもできる。 信号光のスペク トル幅が広くなる と、 上り信号と線路途中で反射した下り信号との相互千渉が抑制さ れ、 上り信号に加算する雑音を抑圧することが可能となる。  In a bidirectional optical transmission system in which direction-division multiplex bidirectional / wavelength multiplex multipoint transmission is performed using a single optical fiber, a downstream signal and an upstream signal are transmitted on the same optical fiber with the same wavelength. Therefore, when the main unit receives an upstream signal, it may interfere with a downstream signal reflected in the middle of the optical fiber. In the present embodiment, the drive current of the light emitting element is controlled so that the signal component is superimposed on the downstream signal, so that the spectrum width of the downstream signal light can be increased. When the spectrum width of the signal light is widened, mutual interference between the upstream signal and the downstream signal reflected in the middle of the line is suppressed, and noise added to the upstream signal can be suppressed.

Claims

請 求 の 範 囲 The scope of the claims
主装置と従装置との間を第一の光ファイバと第二の光フアイ バで 2芯光ファイバ双方向伝送する双方向光伝送方式であつ て、 A bidirectional optical transmission system in which a two-core optical fiber is bidirectionally transmitted between a master device and a slave device using a first optical fiber and a second optical fiber,
前記主装置は、下り信号で変調した信号成分にバイアス成分を 重畳した下り光信号を前記第一の光ファイバに向けて送信す る光送信回路と、前記第二の光ファイバを通して受信した上り 光信号から上り信号を検出する光受信回路とを備え、 前記従装置は、前記第一の光ファイバを通して受信した前記下 り光信号から前記信号成分を検出する光受信回路と、前記受信 した下り光信号の一部を飽和増幅 ·減衰回路によって前記上り 信号で変調した前記上り光信号を前記第二の光ファイバに向 けて送信する光送信回路とを備えることを特徴とする双方向 光 送方式。 主装置と従装置との間を 1芯の光ファイバで方向多重双方向 伝送する双方向光伝送方式であって、 The main device comprises: an optical transmission circuit for transmitting a downstream optical signal in which a bias component is superimposed on a signal component modulated by the downstream signal to the first optical fiber; and an upstream optical signal received through the second optical fiber. An optical receiving circuit that detects an upstream signal from a signal, the slave device detects an optical receiving circuit that detects the signal component from the downstream optical signal received through the first optical fiber, and the received downstream light A bidirectional optical transmission system comprising: an optical transmission circuit that transmits the upstream optical signal, which is obtained by modulating a part of a signal with the upstream signal by a saturation amplification / attenuation circuit, toward the second optical fiber. . A bidirectional optical transmission system in which a single-core optical fiber transmits a multiplexed bidirectional transmission between a master device and a slave device.
前記主装置は、下り信号で変調した信号成分にバイアス成分を 重畳した下り光信号を前記光ファイバに向けて送信する光送 信回路と、前記光ファイバを通して受信した上り光信号から上 り信号を検出する光受信回路とを備え、 The main device comprises: an optical transmission circuit for transmitting a downstream optical signal in which a bias component is superimposed on a signal component modulated by the downstream signal toward the optical fiber; and an upstream signal received from the optical fiber to receive an upstream signal. And a light receiving circuit for detecting,
前記従装置は、前記光ファイバを通して受信した前記下り光信 号から前記信号成分を検出する光受信回路と、前記受信した下 り光信号の一部を飽和増幅 ·減衰回路によって前記上り信号で 変調した前記上り光信号を前記光ファイバに向けて送信する 光送信回路とを備えることを特徴とする双方向光伝送方式。 請求項 2 に記載の主装置と従装置との間を 1芯の光ファイバ で方向多重双方向伝送する双方向光伝送方式において、前記飽 和増幅 ·減衰回路が、 半導体光増幅器であって、 前記下り光信 号の入射端面と対向する端面に劈開状態に比べて高反射率を 有する膜をコーティ ングし、前記下り光信号の入射端面から送 出する反射型構成であることを特徴とする双方向光伝送方式。 主装置と複数の従装置との間を第一の光ファイバと第二の光 ファイバで 2芯光ファイバ双方向 ·波長多重マルチポイント伝 送する双方向光伝送方式であって、 The slave device modulates a portion of the received downstream optical signal with the upstream signal by a saturation amplification / attenuation circuit, and an optical receiving circuit that detects the signal component from the downstream optical signal received through the optical fiber. An optical transmission circuit for transmitting the upstream optical signal toward the optical fiber. 3. The bidirectional optical transmission system according to claim 2, wherein the main device and the slave device are transmitted in a directionally multiplexed bidirectional manner using a single-core optical fiber. A sum amplifying / attenuating circuit, which is a semiconductor optical amplifier, wherein a film having a higher reflectivity than a cleavage state is coated on an end surface facing the incident end surface of the downstream optical signal, and a film is formed from the incident end surface of the downstream optical signal. A bidirectional optical transmission system characterized by a reflection type configuration for transmitting. A bidirectional optical transmission system in which a two-core optical fiber bidirectional / wavelength multiplex multipoint transmission is performed between a master device and a plurality of slave devices using a first optical fiber and a second optical fiber.
前記主装置は、下り信号で変調した信号成分にバイアス成分を 重畳したそれぞれの下り光信号を前記第一の光ファイバに向 けて送信する複数の光送信回路と、前記第二の光ファイバを通 して受信したそれぞれの上り光信号から上り信号を検出する 複数の光受信回路とを備え、 The main device comprises: a plurality of optical transmission circuits for transmitting, toward the first optical fiber, respective downstream optical signals in which a bias component is superimposed on a signal component modulated by a downstream signal; and the second optical fiber. A plurality of optical receiving circuits for detecting an upstream signal from each upstream optical signal received through the
前記複数の従装置は、 それぞれ、 前記第一の光ファイバを通し て受信した前記下り光信号から前記信号成分を検出する光受 信回路と、 それぞれ、 前記受信した下り光信号の一部を飽和増 幅 ·減衰回路によって前記上り信号で変調した前記上り光信号 を前記第二の光ファイバに向けて送信する光送信回路とを備 えることを特徴とする双方向光伝送方式。 主装置と複数の従装置を 1 芯の光フ ァイバで方向多重双方 向,波長多重マルチポイン ト伝送する双方向光伝送方式であつ て、 The plurality of slave devices each include: an optical receiving circuit that detects the signal component from the downstream optical signal received through the first optical fiber; and each saturates a part of the received downstream optical signal. A bidirectional optical transmission system, comprising: an optical transmission circuit that transmits the upstream optical signal modulated by the amplification / attenuation circuit with the upstream signal toward the second optical fiber. A bidirectional optical transmission system in which a master device and a plurality of slave devices are transmitted in a direction-multiplexed bidirectional and wavelength-division multiplexed multipoint using a single optical fiber.
前記主装置は、下り信号で変調した信号成分にバイアス成分を 重畳したそれぞれの下り光信号を前記光ファイバに向けて送 信する複数の光送信回路と、前記光ファイバを通して受信した それぞれの上り光信号から上り信号を検出する複数の光受信 回路とを備え、 The main device comprises: a plurality of optical transmission circuits for transmitting, to the optical fiber, respective downstream optical signals in which a bias component is superimposed on a signal component modulated by a downstream signal; and each upstream light received through the optical fiber. A plurality of optical receiving circuits for detecting an upstream signal from the signal,
前記複数の従装置は、 それぞれ、 前記光ファイバを通して受信 した前記下り光信号から前記信号成分を検出する光受信回路 と、 それぞれ、 前記受信した下り光信号の一部を飽和増幅 ·減 衰回路によって前記上り信号で変調した前記上り光信号を前 記光ファイバに向けて送信する光送信回路とを備えることを 特徴とする双方向光伝送方式。 The plurality of slave units each receive through the optical fiber. An optical receiving circuit that detects the signal component from the downstream optical signal, and an optical receiver that modulates a part of the received downstream optical signal with the upstream signal by a saturation amplification / attenuation circuit. A bidirectional optical transmission system, comprising: an optical transmission circuit that transmits the signal to a fiber.
6 . 請求項 5 に記載の主装置と複数の従装置を 1芯の光ファイバ で方向多重双方向 ·波長多重マルチポイント伝送する双方向光 伝送方式において、 前記飽和増幅 ·減衰回路が、 半導体光増幅 器であって、前記下り光信号の入射端面と対向する端面に劈開 状態に比べて高反射率を有する膜をコーティ ングし、前記下り 光信号の入射端面から送出する反射型構成であることを特徴 とする双方向光伝送方式。 7 主装置と複数の従装置との間を第一の光ファイバと第二の光 ファイバで 2芯光ファイバ双方向 ·波長時分割多重マルチボイ ント伝送する双方向光伝送方式であって、 6. A bidirectional optical transmission system in which a master device and a plurality of slave devices according to claim 5 are transmitted in a directionally multiplexed bidirectional / wavelength multiplexed multipoint manner using a single-core optical fiber. An amplifier having a reflection type configuration in which a film having a higher reflectivity than a cleavage state is coated on an end face facing the incident end face of the downstream optical signal and transmitted from the incident end face of the downstream optical signal. A bidirectional optical transmission system characterized by the following. 7 A bidirectional optical transmission system in which a two-core optical fiber bidirectional and wavelength-division multiplexed multipoint transmission is performed between a master device and a plurality of slave devices using a first optical fiber and a second optical fiber.
前記主装置は、下り信号で変調した信号成分にバイアス成分を 重畳したそれぞれの下り光信号を従装置毎の波長と時間領域 に分離して前記第一の光ファイバに向けて送信する光送信回 路と、前記第二の光ファイバを通して受信したそれぞれの上り 光信号から上り信号を検出する少なく とも 1 の光受信回路と を備え、  The master unit separates each downstream optical signal obtained by superimposing a bias component on a signal component modulated by a downstream signal into a wavelength and a time domain for each slave device, and transmits the separated optical signal toward the first optical fiber. Path, and at least one optical receiving circuit for detecting an upstream signal from each upstream optical signal received through the second optical fiber,
前記複数の従装置は、 それぞれ、 前記第一の光ファイバを通し て受信した前記下り光信号から前記信号成分を検出する光受 信回路と、 それぞれ、 前記受信した下り光信号の一部を飽和増 幅 ·減衰回路によって前記上り信号で変調した前記上り光信号 を前記第二の光ファイバに向けて送信する光送信回路とを備 えることを特徴とする双方向光伝送方式。 請求項 7 に記載の主装置と複数の従装置との間を第一の光フ アイバと第二の光ファイバで 2芯光ファイバ双方向 ·波長時分 割多重マルチポイント伝送する双方向光伝送方式において、前 記光送信回路に光出力の波長を従装置毎の波長に可変できる 波長可変光源を用いたことを特徴とする双方向光伝送方式。 主装置と複数の従装置を 1 芯の光フ ァイバで方向多重双方 向 ·波長多重時分割マルチポイント伝送する双方向光伝送方式 であって、 The plurality of slave devices each include: an optical receiving circuit that detects the signal component from the downstream optical signal received through the first optical fiber; and each saturates a part of the received downstream optical signal. A bidirectional optical transmission system, comprising: an optical transmission circuit that transmits the upstream optical signal modulated by the amplification / attenuation circuit with the upstream signal toward the second optical fiber. A two-way optical transmission system comprising a first optical fiber and a second optical fiber for bidirectional transmission of a two-core optical fiber and wavelength-division multiplexing multipoint transmission between the master device and a plurality of slave devices according to claim 7. A bidirectional optical transmission system, characterized in that a wavelength tunable light source capable of changing the wavelength of optical output to the wavelength of each slave device is used in the optical transmission circuit. A bidirectional optical transmission system in which a master device and a plurality of slave devices are multiplexed in one direction using a single optical fiber.
前記主装置は、下り信号で変調した信号成分にバイアス成分を 重畳したそれぞれの下り光信号を従装置毎の波長と時間領域 に分離して前記光ファイバに向けて送信する光送信回路と、前 記光ファイバを通して受信したそれぞれの上り光信号から上 り信号を検出する少なく とも 1 の光受信回路とを備え、 前記複数の従装置は、 それぞれ、 前記光ファイバを通して受信 した前記下り光信号から前記信号成分を検出する光受信回路 と、 それぞれ、 前記受信した下り光信号の一部を飽和増幅 ·減 衰回路によって前記上り信号で変調した前記上り光信号を前 記光ファイバに向けて送信する光送信回路とを備えることを 特徴とする双方向光伝送方式。 請求項 9 に記載の主装置と複数の従装置を 1芯の光フ アイバで方向多重双方向 ·波長時分割多重マルチポイント伝送 する双方向光伝送方式において、 前記飽和増幅 · 減衰回路が、 半導体光増幅器であって、前記下り光信号の入射端面と対向す る端面に劈開状態に比べて高反射率を有する膜をコ一ティ ン グし、前記下り光信号の入射端面から送出する反射型構成であ ることを特徴とする双方向光伝送方式。 請求項 9に記載の主装置と複数の従装置を 1芯の光フ アイバで方向多重双方向 ·波長時分割多重マルチポイント伝送 する双方向光伝送方式において、前記光送信回路に光出力の波 長を従装置毎の波長に可変できる波長可変光源を用いたこと を特徴とする双方向光伝送方式。 受信した第一の光信号の一部を飽和増幅 · 減衰回路に よって第二の送信信号で変調した第二の光信号を光ファイバ に向けて送信する光送信回路を備える光送受信装置に対して、 第一の送信信号で変調した信号成分にバイアス成分を重畳し た第一の光信号を送信する光送信回路と、 An optical transmission circuit that separates each downstream optical signal in which a bias component is superimposed on a signal component modulated by a downstream signal into a wavelength and a time domain for each slave device and transmits the separated optical signal toward the optical fiber; At least one optical receiving circuit for detecting an upstream signal from each upstream optical signal received through the optical fiber, wherein each of the plurality of slave devices is configured to detect the upstream signal from the downstream optical signal received through the optical fiber. An optical receiving circuit that detects a signal component; anda light that transmits the upstream optical signal, which is obtained by modulating a part of the received downstream optical signal with the upstream signal by a saturation amplification / attenuation circuit, toward the optical fiber. A bidirectional optical transmission system comprising a transmission circuit. 10. The bidirectional optical transmission system according to claim 9, wherein the master device and the plurality of slave devices are transmitted in a single-core optical fiber in a direction multiplexed bidirectional / wavelength time division multiplexed multipoint transmission. An optical amplifier, wherein a coating having a higher reflectivity than the cleavage state is coated on an end face opposite to the incident end face of the downstream optical signal, and a reflection type light is transmitted from the incident end face of the downstream optical signal. A bidirectional optical transmission system characterized by having a configuration. 10. A bidirectional optical transmission system in which a master device and a plurality of slave devices according to claim 9 are directionally multiplexed bidirectionally and wavelength time division multiplexed multipoint transmitted by a single optical fiber. A bidirectional optical transmission system characterized by using a wavelength tunable light source whose length can be varied to the wavelength of each slave device. An optical transmitter / receiver having an optical transmission circuit for transmitting a second optical signal, which is obtained by modulating a part of the received first optical signal with a second transmission signal by a saturation amplification / attenuation circuit, toward an optical fiber, An optical transmission circuit for transmitting a first optical signal in which a bias component is superimposed on a signal component modulated by the first transmission signal;
光ファイバを通して受信した前記第二の光信号から信号成分 を検出する光受信回路とを備える光送受信装置。 信号で変調した信号成分にバイアス成分を重畳した光 信号を、 光ファイバを通して受信する光受信回路と、 前記受信 した光信号の一部を飽和増幅 ·減衰回路によって送信する信号 で変調して光ファイバに向けて送信する光送信回路とを備え る光送受信装置。 請求項 1 2 に記載の光送受信装置において、 前記バイ ァス成分が前記信号成分の 5 0 %以上、好ましくは 1 0 0 %以 上であることを特徴とする光送受信装置。 請求項 1 3 に記載の光送受信装置において、 前記飽和 増幅 ·減衰回路が、 制御電流によって増幅度を制御する増幅部 と送信する信号によって光信号を変調する変調部とを有する 半導体光増幅器であることを特徴とする光送受信装置。 請求項 1 3 に記載の光送受信装置において、 前記飽和 増幅 ·減衰回路が、 制御電流によって飽和させる増幅部と送信 する信号によって光信号を吸収する変調部とを有する半導体 光素子であることを特徴とする光送受信装置。 An optical transmitting and receiving device comprising: an optical receiving circuit that detects a signal component from the second optical signal received through an optical fiber. An optical receiving circuit that receives an optical signal obtained by superimposing a bias component on a signal component modulated by a signal through an optical fiber; and an optical fiber that modulates a part of the received optical signal with a signal that is transmitted by a saturation amplification / attenuation circuit. An optical transmitting and receiving device comprising: an optical transmitting circuit that transmits the signal to the optical transmitter. 13. The optical transceiver according to claim 12, wherein the bias component is at least 50%, preferably at least 100% of the signal component. 14. The optical transmitting and receiving apparatus according to claim 13, wherein the saturation amplification / attenuation circuit is a semiconductor optical amplifier including: an amplification unit that controls an amplification degree by a control current; and a modulation unit that modulates an optical signal by a signal to be transmitted. An optical transmission / reception device characterized by the above-mentioned. 14. The optical transmitting and receiving device according to claim 13, wherein the saturation amplification / attenuation circuit is a semiconductor optical device having an amplification unit that saturates by a control current and a modulation unit that absorbs an optical signal by a signal to be transmitted. An optical transceiver.
PCT/JP2003/006530 2002-05-27 2003-05-26 Bidirectional optical transmission system and optical transmission/reception device WO2003103194A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU2003241767A AU2003241767A1 (en) 2002-05-27 2003-05-26 Bidirectional optical transmission system and optical transmission/reception device
JP2004510151A JP4369363B2 (en) 2002-05-27 2003-05-26 Bidirectional optical transmission system and optical transceiver

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2002-152589 2002-05-27
JP2002152589 2002-05-27

Publications (1)

Publication Number Publication Date
WO2003103194A1 true WO2003103194A1 (en) 2003-12-11

Family

ID=29706437

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2003/006530 WO2003103194A1 (en) 2002-05-27 2003-05-26 Bidirectional optical transmission system and optical transmission/reception device

Country Status (3)

Country Link
JP (1) JP4369363B2 (en)
AU (1) AU2003241767A1 (en)
WO (1) WO2003103194A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2068469A1 (en) * 2007-12-06 2009-06-10 Alcatel Lucent Method for circulating optical signals in a passive optical distribution network

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6451733A (en) * 1987-08-21 1989-02-28 Fujitsu Ltd Frequency multiplex optical communication system
JPH10229385A (en) * 1997-02-13 1998-08-25 Nippon Telegr & Teleph Corp <Ntt> Two-way transmission system
JP2000232413A (en) * 1999-02-10 2000-08-22 Nec Corp Optical subscriber system, and two-way optical transmission system using the same
JP2002044031A (en) * 2000-07-26 2002-02-08 Mitsubishi Electric Corp Optical receiver of optical subcarrier transmitting equipment

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6451733A (en) * 1987-08-21 1989-02-28 Fujitsu Ltd Frequency multiplex optical communication system
JPH10229385A (en) * 1997-02-13 1998-08-25 Nippon Telegr & Teleph Corp <Ntt> Two-way transmission system
JP2000232413A (en) * 1999-02-10 2000-08-22 Nec Corp Optical subscriber system, and two-way optical transmission system using the same
JP2002044031A (en) * 2000-07-26 2002-02-08 Mitsubishi Electric Corp Optical receiver of optical subcarrier transmitting equipment

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2068469A1 (en) * 2007-12-06 2009-06-10 Alcatel Lucent Method for circulating optical signals in a passive optical distribution network

Also Published As

Publication number Publication date
JP4369363B2 (en) 2009-11-18
AU2003241767A1 (en) 2003-12-19
JPWO2003103194A1 (en) 2005-10-06

Similar Documents

Publication Publication Date Title
KR100711201B1 (en) The long-reach wavelength division multiplexing passive optical networks by using the position adjustment of broadband light source
JP5941150B2 (en) Configuration for coexisting GPON and XGPON optical communication systems
EP2157722B1 (en) WDM PON RF overlay architecture based on quantum dot multi-wavelength laser source
JP5808859B2 (en) Optical access network
JP5482128B2 (en) Optical communication network and supervisory control device
US8798469B2 (en) Optical network element and optical transmission system
JP5305377B2 (en) Optical transmission system using Raman optical amplification
US20090317078A1 (en) Optical transmission device and optical transmission method
EP2656520B1 (en) Method and arrangement for receiving an optical input signal and transmittning an optical output signal
US5323474A (en) Lossless optical signal splitter including remotely pumped amplifier
KR20060100127A (en) Wdm transmission system using shared seed light source
JP2015119235A (en) Wavelength multiplex optical communication system, optical transmitter, and wavelength multiplex optical communication method
US8320771B2 (en) Optical transmission system and repeater
US20140376912A1 (en) Optical access network
CN113395114B (en) Optical module, data center system and data transmission method
WO2003103194A1 (en) Bidirectional optical transmission system and optical transmission/reception device
JP2001257646A (en) Optical amplifier and wavelength multiplex optical communication system provided with the optical amplifier
US20240137142A1 (en) Monitior window in ase injection seed
JP2010193181A (en) Optical transmission system, wavelength router, subscriber terminal device, and optical transmission method
KR101097743B1 (en) Multicast signal transmission system using wavelength modulation filter on WDM-PON
JP2011147024A (en) Station-side device, subscriber-side device, optical communication system, and optical communication method
KR101836225B1 (en) Method for minimizing Rayleigh-induced penalty in long-reach wavelength-division-multiplexed passive optical network and wavelength-division-multiplexed passive optical network system
KR100547721B1 (en) Optical amplifier module and optical transmission system using same
KR20220132795A (en) Multi-channel optical transmission device
KR101062395B1 (en) Optical amplifier

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NI NO NZ OM PH PL PT RO RU SC SD SE SG SK SL TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 2004510151

Country of ref document: JP

122 Ep: pct application non-entry in european phase