WO2024134710A1 - Optical communication system, transmission device, reception device, and control method - Google Patents

Optical communication system, transmission device, reception device, and control method Download PDF

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Publication number
WO2024134710A1
WO2024134710A1 PCT/JP2022/046615 JP2022046615W WO2024134710A1 WO 2024134710 A1 WO2024134710 A1 WO 2024134710A1 JP 2022046615 W JP2022046615 W JP 2022046615W WO 2024134710 A1 WO2024134710 A1 WO 2024134710A1
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Prior art keywords
communication device
optical signal
transmitting
notch
receiving
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PCT/JP2022/046615
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French (fr)
Japanese (ja)
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康就 田中
一貴 原
遼 胡間
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日本電信電話株式会社
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Priority to PCT/JP2022/046615 priority Critical patent/WO2024134710A1/en
Priority to PCT/JP2023/045283 priority patent/WO2024135613A1/en
Publication of WO2024134710A1 publication Critical patent/WO2024134710A1/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/50—Transmitters
    • H04B10/572—Wavelength control
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/60—Receivers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/60—Receivers
    • H04B10/66—Non-coherent receivers, e.g. using direct detection
    • H04B10/69—Electrical arrangements in the receiver

Definitions

  • the present invention relates to technologies for optical communication systems, transmitting devices, receiving devices, and control methods.
  • the zero-dispersion wavelength of optical fibers fluctuates between 1300 and 1324 nm, if the zero-dispersion wavelength value of each optical fiber being used is not known, there is a problem in that the wavelength cannot be set.
  • a method of setting the wavelength using an OTDR can be considered, as shown in Figure 7.
  • OTDR Optical Time Domain Reflectometer
  • light emitted from the OTDR of device A is sent to device B, and then returned to the OTDR of device A by a mirror in device B, measuring the zero dispersion value and switching the path between the transmitter and receiver.
  • this method requires additional equipment, which makes the system more complicated.
  • the present invention aims to provide a technology that can suppress the misalignment between the zero dispersion wavelength of an optical fiber and the transmission wavelength.
  • One aspect of the present invention is an optical communication system including a first communication device and a second communication device
  • the first communication device includes a first transmitter that transmits an optical signal with a transmission wavelength ⁇ to the second communication device, a first receiver that receives a deviation from zero dispersion ⁇ from the second communication device, and a first signal processor that changes the transmission wavelength of the optical signal transmitted by the first transmitter to ⁇ + ⁇ or ⁇ - ⁇
  • the second communication device includes a second receiver that receives an optical signal from the first communication device, a second signal processor that determines the notch frequency at which a notch first appears other than at a frequency multiple of the received optical signal from the frequency spectrum of the received optical signal, determines dispersion from the determined notch frequency, a predetermined chirp value, and the distance between the first communication device and the second communication device, and determines the deviation ⁇ from zero dispersion from the determined dispersion, and a second transmitter that transmits the deviation ⁇ to the first communication device.
  • One aspect of the present invention is a transmitting device in an optical communication system including a transmitting device and a receiving device, the transmitting device comprising: a transmitting section that transmits an optical signal with a transmission wavelength ⁇ to the receiving device; a receiving section that receives an amount of deviation from zero dispersion ⁇ from the receiving device; and a signal processing section that changes the transmission wavelength of the optical signal transmitted by the transmitting section to ⁇ + ⁇ or ⁇ - ⁇ .
  • One aspect of the present invention is a receiving device in an optical communication system including a transmitting device and a receiving device, the receiving device comprising: a receiving unit that receives an optical signal from the transmitting device; a signal processing unit that determines, from the frequency spectrum of the received optical signal, the notch frequency at which a notch first appears other than at a frequency multiple of the received optical signal; determines dispersion from the determined notch frequency, a predetermined chirp value, and the distance between the transmitting device and the receiving device; determines a deviation amount ⁇ from zero dispersion from the determined dispersion; and a transmitting unit that transmits the deviation amount ⁇ to the transmitting device.
  • One aspect of the present invention is a control method for an optical communication system including a first communication device and a second communication device, the control method comprising the steps of: the first communication device transmitting an optical signal with a transmission wavelength ⁇ to the second communication device; receiving from the second communication device a deviation from zero dispersion ⁇ ; and changing the transmission wavelength of the transmitted optical signal to ⁇ + ⁇ or ⁇ - ⁇ ; and the second communication device receiving an optical signal from the first communication device; determining from the frequency spectrum of the received optical signal a notch frequency at which a notch first appears other than at a frequency multiple of the received optical signal, determining dispersion from the determined notch frequency, a predetermined chirp value, and the distance between the first communication device and the second communication device, determining the deviation ⁇ from zero dispersion from the determined dispersion; and transmitting the deviation ⁇ to the first communication device.
  • One aspect of the present invention is a method for controlling a transmitting device in an optical communication system including a transmitting device and a receiving device, the method comprising the steps of transmitting an optical signal with a transmission wavelength ⁇ to the receiving device, receiving an amount of deviation from zero dispersion ⁇ from the receiving device, and changing the transmission wavelength of the optical signal transmitted by the transmitting unit to ⁇ + ⁇ or ⁇ - ⁇ .
  • One aspect of the present invention is a method for controlling a receiving device in an optical communication system including a transmitting device and a receiving device, the receiving device comprising the steps of receiving an optical signal from the transmitting device, determining from the frequency spectrum of the received optical signal the notch frequency at which a notch first appears other than at a frequency multiple of the received optical signal, determining dispersion from the determined notch frequency, a predetermined chirp value, and the distance between the transmitting device and the receiving device, determining a deviation ⁇ from zero dispersion from the determined dispersion, and transmitting the deviation ⁇ to the transmitting device.
  • the present invention makes it possible to suppress the deviation between the zero dispersion wavelength of an optical fiber and the transmission wavelength.
  • FIG. 13 is a block diagram showing a configuration of an optical communication system according to an embodiment.
  • FIG. 13 is a diagram showing an example of a notch frequency f0.
  • FIG. 13 is a diagram illustrating a configuration of a modified example of the optical communication system.
  • FIG. 2 is a sequence diagram showing a process flow in the optical communication system.
  • FIG. 2 is a sequence diagram showing a process flow in the optical communication system.
  • FIG. 2 is a sequence diagram showing a process flow in the optical communication system.
  • FIG. 13 is a diagram showing a configuration example using a current controller and a wavelength tunable laser.
  • FIG. 1 is a diagram showing an example of a configuration using an array laser 180A and a multiplexer 190A.
  • FIG. 1 is a diagram showing a configuration example using an OTDR.
  • FIG. 1 is a block diagram showing a configuration of an optical communication system 10 according to an embodiment.
  • the optical communication system 10 is composed of a communication device 100A and a communication device 100B.
  • the communication devices 100A and 100B perform optical communication via optical fibers.
  • the communication device 100A is an example of a first communication device.
  • the communication device 100B is an example of a second communication device.
  • the communication device 100A is composed of a signal processing unit 110A, a temperature controller 120A, a transmitting unit 130A, and a receiving unit 140A.
  • the receiving unit 140A receives a signal from the communication device 100B and outputs it to the signal processing unit 110A.
  • the signal processing unit 110A sets the wavelength of the optical signal to be transmitted to the communication device 100B.
  • the signal processing unit 110A can refer to correspondence information indicating the correspondence between wavelength and temperature. By referring to the correspondence information, the signal processing unit 110A obtains the temperature corresponding to the wavelength of the optical signal to be transmitted to the communication device 100B, and sets the temperature controller 120A to the obtained temperature.
  • the temperature controller 120A adjusts the transmitting unit 130A to the set temperature.
  • the transmitting unit 130A is, for example, a wavelength-variable laser, and transmits an optical signal with a wavelength according to the temperature.
  • the communication device 100B is composed of a signal processing unit 110B, a temperature controller 120B, a transmission unit 130B, and a reception unit 140B.
  • the reception unit 140B receives a signal from the communication device 100A and outputs it to the signal processing unit 110B.
  • the signal processing unit 110B calculates the deviation amount ⁇ from zero dispersion.
  • the signal processing unit 110B finds the notch frequency at which a notch first appears other than multiples of the frequency of the received optical signal from the frequency spectrum of the received optical signal.
  • a notch frequency is a point where the slope of the average line of the frequency spectrum changes from negative to positive and is a point other than multiples of the frequency of the transmitted signal.
  • Figure 2 is a diagram showing an example of a notch frequency f0. In Figure 2, the horizontal axis indicates frequency and the vertical axis indicates power. f0 and f1 are shown as notch frequencies, but since f0 is the first of these to appear, the notch frequency at which the notch first appears is f0.
  • Signal processing unit 110B calculates the dispersion from the calculated notch frequency, a predetermined chirp value, and the distance between communication device 100A and communication device 100B, and calculates the deviation ⁇ from zero dispersion from the calculated dispersion.
  • the dispersion is calculated by the following formula 1.
  • D represents the dispersion
  • ⁇ represents the chirp value
  • L represents the distance between communication device 100A and communication device 100B
  • c represents the speed of light.
  • D c/(2(f0) 2 ⁇ 2 L) (1-(2/ ⁇ ) arctan ⁇ )...(Formula 1)
  • the deviation amount ⁇ is calculated by the following formula 2.
  • ⁇ D/0.092...(Formula 2)
  • the value of the dispersion slope of the fiber being used may be used, or the value of the dispersion slope specified by standardization may be used.
  • the signal processing unit 110B causes the transmitting unit 130B to transmit the determined deviation amount ⁇ to the communication device 100A.
  • the signal processing unit 110B causes the transmitting unit 130B to transmit notch appearance information indicating whether or not a notch has appeared to the communication device 100A.
  • D at fn can also be calculated using the following equation 3.
  • D c/(2(fn) 2 ⁇ 2 L) (1+2n-(2/ ⁇ )arctan ⁇ )...(Formula 3)
  • the calculation can be simplified by ignoring ⁇ .
  • the signal processing unit 110B can refer to correspondence information that indicates the correspondence relationship between wavelength and temperature. By referring to the correspondence information, the signal processing unit 110B obtains the temperature that corresponds to the wavelength of the optical signal to be transmitted to the communication device 100A, and sets the temperature controller 120B to the obtained temperature. The temperature controller 120B adjusts the transmitting unit 130B to the set temperature.
  • the transmitting unit 130B is, for example, a tunable laser, and transmits an optical signal with a wavelength according to the temperature.
  • the communication device 100A receives the deviation ⁇ from zero dispersion from the communication device 100B by the receiver 140A.
  • the signal processor 110A changes the transmission wavelength of the optical signal transmitted by the transmitter 130A to ⁇ + ⁇ or ⁇ - ⁇ . For example, when the deviation ⁇ is received, the signal processor 110A first changes the wavelength to ⁇ + ⁇ . If the wavelength is changed to ⁇ + ⁇ and a notch does not appear, the signal processor 110A keeps the wavelength at ⁇ + ⁇ . If a notch appears even when the wavelength is changed to ⁇ + ⁇ , the signal processor 110A changes the wavelength to ⁇ - ⁇ .
  • the signal processor 110A changes the transmission wavelength of the optical signal to either ⁇ + ⁇ or ⁇ - ⁇ (for example, ⁇ + ⁇ )
  • the signal processor 110A further changes the transmission wavelength to the other (for example, ⁇ - ⁇ ).
  • this embodiment does not use an OTDR, mirrors, or the like, so no additional equipment is required, and it is possible to suppress the deviation between the zero dispersion wavelength of the optical fiber and the transmission wavelength without incurring costs and with a simple configuration.
  • FIG. 3 is a diagram showing the configuration of a modified example of an optical communication system using a multiplexing/demultiplexing device.
  • the configuration is a single-core bidirectional configuration using a multiplexing/demultiplexing device. That is, the communication device 1100A includes a multiplexing/demultiplexing device 150A. The transmitting unit 130A outputs an optical signal to the multiplexing/demultiplexing device 150A. The receiving unit 140A receives an optical signal from the multiplexing/demultiplexing device 150A. Similarly, the communication device 1100B includes a multiplexing/demultiplexing device 150B.
  • the transmitting unit 130B outputs an optical signal to the multiplexing/demultiplexing device 150B.
  • the receiving unit 140B receives an optical signal from the multiplexing/demultiplexing device 150B.
  • Examples of the multiplexing/demultiplexing device include a circulator and a multiplexing/demultiplexing coupler. It is preferable that the multiplexing/demultiplexing device is wavelength independent.
  • this embodiment does not use an OTDR or mirrors, so no additional equipment is required, and it is therefore possible to suppress the deviation between the zero dispersion wavelength of the optical fiber and the transmission wavelength without incurring costs and with a simple configuration.
  • Figures 4A, 4B, and 4C are sequence diagrams showing the process flow in optical communication system 10. Note that these sequence diagrams also show the process flow in optical communication system 20.
  • the communication device 100A transmits an optical signal with a wavelength ⁇ (step S101).
  • the communication device 100B receives the optical signal (step S102).
  • the communication device 100B determines the notch frequency f0 (step S103), and determines the deviation amount ⁇ (step S104).
  • the communication device 100B transmits the deviation amount ⁇ and notch appearance information (present) to the communication device 100A (step S105).
  • the notch appearance information (present) indicates that a notch has appeared.
  • the notch appearance information (absent) indicates that a notch has not appeared.
  • the communication device 100A receives the deviation amount ⁇ and the presence of a notch (step S106) and changes the transmission wavelength to ⁇ + ⁇ (step S107).
  • the communication device 100B receives the optical signal (step S108).
  • the communication device 100B determines whether a notch has appeared (step S109).
  • step S109 The case where it is determined in step S109 that a notch has not been applied will be described with reference to FIG. 4B.
  • communication device 100B transmits notch appearance information (none) to communication device 100A (step S201).
  • Communication device 100A receives the absence of a notch (step S2020). In this case, the transmission wavelength is not changed to ⁇ + ⁇ .
  • step S109 The case where it is determined in step S109 that a notch has been applied will be described with reference to FIG. 4C.
  • communication device 100B transmits the amount of deviation ⁇ and notch appearance information (present) to communication device 100A (step S301).
  • Communication device 100A receives the amount of deviation ⁇ and the presence of a notch (step S302), and changes the transmission wavelength to ⁇ - ⁇ (step S303).
  • Fig. 5 is a diagram showing an example configuration using a current controller 160A and a tunable laser 170A.
  • the signal processing unit 110A can refer to correspondence information indicating the correspondence between wavelength and current.
  • the signal processing unit 110A obtains a current corresponding to the wavelength of the optical signal to be transmitted to the communication device 100A, and sets the current controller 160A to apply the obtained current to the tunable laser 170A.
  • the current controller 160A applies the set current to the tunable laser 170A.
  • FIG. 6 is a diagram showing an example configuration using an array laser 180A including lasers capable of emitting each of the wavelengths ⁇ 1 to ⁇ m, and a multiplexer 190A.
  • the signal processing unit 110A selects an oscillation laser corresponding to the desired wavelength, and sets the array laser 180A so that a signal is generated by the selected oscillation laser.
  • the array laser 180A drives the set oscillation laser, and the optical signal generated by this is multiplexed by the multiplexer 190A, and the optical signal is transmitted to the opposing device.
  • any method of changing the wavelength may be used.
  • this embodiment is applicable as long as the zero dispersion wavelength of the optical fiber and the range of the transmission wavelength overlap (not limited to wavelengths between 1300 and 1324 nm).
  • the transmitting side is described as communication device 100A, but since communication device 100B has the same configuration as communication device 100A, communication device 100B can also suppress the deviation between the zero dispersion wavelength of the optical fiber and the transmission wavelength.
  • the signal processing units 110A and 110B may be configured using a processor such as a CPU (Central Processing Unit) and a memory.
  • the signal processing units 110A and 110B function as the signal processing units 110A and 110B by the processor executing a program.
  • all or part of the functions of the signal processing units 110A and 110B may be realized using hardware such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array).
  • the above program may be recorded on a computer-readable recording medium.
  • Examples of computer-readable recording media include portable media such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, and a semiconductor storage device (e.g., an SSD: Solid State Drive), and storage devices such as a hard disk and a semiconductor storage device built into a computer system.
  • portable media such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, and a semiconductor storage device (e.g., an SSD: Solid State Drive), and storage devices such as a hard disk and a semiconductor storage device built into a computer system.
  • SSD Solid State Drive
  • the present invention is applicable to optical communication systems that communicate using optical fibers.
  • Optical communication system 100A, 100B Communication device, 110A, 110B Signal processing unit, 120A, 120B Temperature controller, 130A, 130B Transmitter, 140A, 140B Receiver, 150A, 150B Multiplexer/demultiplexer device, 160A Current controller, 170A Tunable laser, 180A Array laser, 190A Multiplexer, 1100A, 1100B Communication device

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Abstract

According to an aspect of the present invention, a first communication device has a first transmission unit that transmits an optical signal of a transmission wavelength λ to a second communication device, a deviation amount ∆λ from zero dispersion is received from the second communication device, and the transmission wavelength of the optical signal that is transmitted is changed to λ+∆λ or λ-∆λ. The second communication device receives the optical signal from the first communication device, finds a notch frequency where a notch first appears in a frequency spectrum of the optical signal that is received, at other than a multiple of the frequency of the optical signal that is received, finds a dispersion from the notch frequency that is found, a predetermined chirp value, and distance between the first communication device and the second communication device, finds the deviation amount ∆λ from zero dispersion from the dispersion that is found, and transmits the deviation amount ∆λ to the first communication device.

Description

光通信システム、送信装置、受信装置、および制御方法Optical communication system, transmitting device, receiving device, and control method
　本発明は、光通信システム、送信装置、受信装置、および制御方法の技術に関する。 The present invention relates to technologies for optical communication systems, transmitting devices, receiving devices, and control methods.
　光ファイバを用いて信号を伝送する通信システムにおいて、光ファイバの零分散波長の値から波長がずれると、分散の影響が大きくなりペナルティ量が増加するため、長距離伝送が困難になる。そのため、長距離伝送するためには、零分散波長の値に近づけるように波長を設定する必要がある。 In a communication system that transmits signals using optical fiber, if the wavelength deviates from the zero-dispersion wavelength of the optical fiber, the effect of dispersion becomes greater and the penalty amount increases, making long-distance transmission difficult. Therefore, in order to transmit over long distances, it is necessary to set the wavelength so that it approaches the zero-dispersion wavelength.
　光ファイバは１３００～１３２４ｎｍの間で零分散波長の値にゆらぎが生じるため、使用する光ファイバごとに零分散波長の値を知らない場合には、波長を設定することができない問題がある。 Since the zero-dispersion wavelength of optical fibers fluctuates between 1300 and 1324 nm, if the zero-dispersion wavelength value of each optical fiber being used is not known, there is a problem in that the wavelength cannot be set.
　そこで、図７に示されるように、ＯＴＤＲ（Optical Time Domain Reflectometer）を用いて波長を設定する方法が考えられる。この方法は、例えば装置ＡのＯＴＤＲから発した光を装置Ｂまで送信し、装備Ｂのミラーによって装置ＡのＯＴＤＲまで戻すことで零分散の値を測定し、送信器と受信器に経路を切り替える方法である。しかし、この方法では、追加の設備が必要になるのでシステムが複雑になる問題がある。 As a result, a method of setting the wavelength using an OTDR (Optical Time Domain Reflectometer) can be considered, as shown in Figure 7. In this method, for example, light emitted from the OTDR of device A is sent to device B, and then returned to the OTDR of device A by a mirror in device B, measuring the zero dispersion value and switching the path between the transmitter and receiver. However, this method requires additional equipment, which makes the system more complicated.
　上記事情に鑑み、本発明は、光ファイバの零分散波長と送信波長とのずれを抑制可能な技術の提供を目的としている。 In light of the above circumstances, the present invention aims to provide a technology that can suppress the misalignment between the zero dispersion wavelength of an optical fiber and the transmission wavelength.
　本発明の一態様は、第１通信装置と第２通信装置とを含む光通信システムであって、第１通信装置は、送信波長λの光信号を第２通信装置に送信する第１送信部と、第２通信装置から、零分散からのずれ量Δλを受信する第１受信部と、第１送信部によって送信される光信号の送信波長をλ＋Δλまたはλ－Δλに変化させる第１信号処理部と、を備え、第２通信装置は、第１通信装置から光信号を受信する第２受信部と、受信した光信号の周波数スペクトルから受信した光信号の周波数倍以外のところで最初にノッチが出現したノッチ周波数を求め、求めたノッチ周波数と、所定のチャープ値と、第１通信装置と第２通信装置との距離と、から分散を求め、求めた分散から零分散からのずれ量Δλを求める第２信号処理部と、ずれ量Δλを第１通信装置に送信する第２送信部と、を備えた光通信システムである。 One aspect of the present invention is an optical communication system including a first communication device and a second communication device, the first communication device includes a first transmitter that transmits an optical signal with a transmission wavelength λ to the second communication device, a first receiver that receives a deviation from zero dispersion Δλ from the second communication device, and a first signal processor that changes the transmission wavelength of the optical signal transmitted by the first transmitter to λ+Δλ or λ-Δλ, and the second communication device includes a second receiver that receives an optical signal from the first communication device, a second signal processor that determines the notch frequency at which a notch first appears other than at a frequency multiple of the received optical signal from the frequency spectrum of the received optical signal, determines dispersion from the determined notch frequency, a predetermined chirp value, and the distance between the first communication device and the second communication device, and determines the deviation Δλ from zero dispersion from the determined dispersion, and a second transmitter that transmits the deviation Δλ to the first communication device.
　本発明の一態様は、送信装置と受信装置とを含む光通信システムにおける送信装置であって、送信波長λの光信号を受信装置に送信する送信部と、受信装置から、零分散からのずれ量Δλを受信する受信部と、送信部によって送信される光信号の送信波長をλ＋Δλまたはλ－Δλに変化させる信号処理部と、を備えた送信装置である。 One aspect of the present invention is a transmitting device in an optical communication system including a transmitting device and a receiving device, the transmitting device comprising: a transmitting section that transmits an optical signal with a transmission wavelength λ to the receiving device; a receiving section that receives an amount of deviation from zero dispersion Δλ from the receiving device; and a signal processing section that changes the transmission wavelength of the optical signal transmitted by the transmitting section to λ+Δλ or λ-Δλ.
　本発明の一態様は、送信装置と受信装置とを含む光通信システムにおける受信装置であって、送信装置から光信号を受信する受信部と、受信した光信号の周波数スペクトルから受信した光信号の周波数倍以外のところで最初にノッチが出現したノッチ周波数を求め、求めたノッチ周波数と、所定のチャープ値と、送信装置と受信装置との距離と、から分散を求め、求めた分散から零分散からのずれ量Δλを求める信号処理部と、ずれ量Δλを送信装置に送信する送信部と、を備えた受信装置である。 One aspect of the present invention is a receiving device in an optical communication system including a transmitting device and a receiving device, the receiving device comprising: a receiving unit that receives an optical signal from the transmitting device; a signal processing unit that determines, from the frequency spectrum of the received optical signal, the notch frequency at which a notch first appears other than at a frequency multiple of the received optical signal; determines dispersion from the determined notch frequency, a predetermined chirp value, and the distance between the transmitting device and the receiving device; determines a deviation amount Δλ from zero dispersion from the determined dispersion; and a transmitting unit that transmits the deviation amount Δλ to the transmitting device.
　本発明の一態様は、第１通信装置と第２通信装置とを含む光通信システムの制御方法であって、第１通信装置が、送信波長λの光信号を第２通信装置に送信するステップと、第２通信装置から、零分散からのずれ量Δλを受信するステップと、送信される光信号の送信波長をλ＋Δλまたはλ－Δλに変化させるステップと、を備え、第２通信装置が、第１通信装置から光信号を受信するステップと、受信した光信号の周波数スペクトルから受信した光信号の周波数倍以外のところで最初にノッチが出現したノッチ周波数を求め、求めたノッチ周波数と、所定のチャープ値と、第１通信装置と第２通信装置との距離と、から分散を求め、求めた分散から零分散からのずれ量Δλを求めるステップと、ずれ量Δλを第１通信装置に送信するステップと、を備えた制御方法である。 One aspect of the present invention is a control method for an optical communication system including a first communication device and a second communication device, the control method comprising the steps of: the first communication device transmitting an optical signal with a transmission wavelength λ to the second communication device; receiving from the second communication device a deviation from zero dispersion Δλ; and changing the transmission wavelength of the transmitted optical signal to λ+Δλ or λ-Δλ; and the second communication device receiving an optical signal from the first communication device; determining from the frequency spectrum of the received optical signal a notch frequency at which a notch first appears other than at a frequency multiple of the received optical signal, determining dispersion from the determined notch frequency, a predetermined chirp value, and the distance between the first communication device and the second communication device, determining the deviation Δλ from zero dispersion from the determined dispersion; and transmitting the deviation Δλ to the first communication device.
　本発明の一態様は、送信装置と受信装置とを含む光通信システムにおける送信装置の制御方法であって、送信波長λの光信号を受信装置に送信するステップと、受信装置から、零分散からのずれ量Δλを受信するステップと、送信部によって送信される光信号の送信波長をλ＋Δλまたはλ－Δλに変化させるステップと、を備えた制御方法である。 One aspect of the present invention is a method for controlling a transmitting device in an optical communication system including a transmitting device and a receiving device, the method comprising the steps of transmitting an optical signal with a transmission wavelength λ to the receiving device, receiving an amount of deviation from zero dispersion Δλ from the receiving device, and changing the transmission wavelength of the optical signal transmitted by the transmitting unit to λ+Δλ or λ-Δλ.
　本発明の一態様は、送信装置と受信装置とを含む光通信システムにおける受信装置の制御方法であって、送信装置から光信号を受信するステップと、受信した光信号の周波数スペクトルから受信した光信号の周波数倍以外のところで最初にノッチが出現したノッチ周波数を求め、求めたノッチ周波数と、所定のチャープ値と、送信装置と受信装置との距離と、から分散を求め、求めた分散から零分散からのずれ量Δλを求めるステップと、ずれ量Δλを送信装置に送信するステップと、を備えた受信装置である。 One aspect of the present invention is a method for controlling a receiving device in an optical communication system including a transmitting device and a receiving device, the receiving device comprising the steps of receiving an optical signal from the transmitting device, determining from the frequency spectrum of the received optical signal the notch frequency at which a notch first appears other than at a frequency multiple of the received optical signal, determining dispersion from the determined notch frequency, a predetermined chirp value, and the distance between the transmitting device and the receiving device, determining a deviation Δλ from zero dispersion from the determined dispersion, and transmitting the deviation Δλ to the transmitting device.
　本発明により、光ファイバの零分散波長と送信波長とのずれを抑制することが可能となる。 The present invention makes it possible to suppress the deviation between the zero dispersion wavelength of an optical fiber and the transmission wavelength.
実施形態における光通信システムの構成を示すブロック図である。1 is a block diagram showing a configuration of an optical communication system according to an embodiment. ノッチ周波数ｆ０の一例を示す図である。FIG. 13 is a diagram showing an example of a notch frequency f0. 光通信システムの変形例の構成を示す図である。FIG. 13 is a diagram illustrating a configuration of a modified example of the optical communication system. 光通信システムにおける処理の流れを示すシーケンス図である。FIG. 2 is a sequence diagram showing a process flow in the optical communication system. 光通信システムにおける処理の流れを示すシーケンス図である。FIG. 2 is a sequence diagram showing a process flow in the optical communication system. 光通信システムにおける処理の流れを示すシーケンス図である。FIG. 2 is a sequence diagram showing a process flow in the optical communication system. 電流コントローラと波長可変レーザを用いた構成例を示す図である。FIG. 13 is a diagram showing a configuration example using a current controller and a wavelength tunable laser. アレイレーザ１８０Ａと合波器１９０Ａを用いた構成例を示す図である。FIG. 1 is a diagram showing an example of a configuration using an array laser 180A and a multiplexer 190A. ＯＴＤＲを用いた構成例を示す図である。FIG. 1 is a diagram showing a configuration example using an OTDR.
　本発明の実施形態について、図面を参照して詳細に説明する。
　図１は、実施形態における光通信システム１０の構成を示すブロック図である。光通信システム１０は、通信装置１００Ａおよび通信装置１００Ｂとで構成される。通信装置１００Ａ、通信装置１００Ｂは、光ファイバにより光通信を行う。本実施形態において、通信装置１００Ａは第１通信装置の一例である。通信装置１００Ｂは第２通信装置の一例である。 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings.
1 is a block diagram showing a configuration of an optical communication system 10 according to an embodiment. The optical communication system 10 is composed of a communication device 100A and a communication device 100B. The communication devices 100A and 100B perform optical communication via optical fibers. In this embodiment, the communication device 100A is an example of a first communication device. The communication device 100B is an example of a second communication device.
　通信装置１００Ａは、信号処理部１１０Ａ、温度コントローラ１２０Ａ、送信部１３０Ａ、および受信部１４０Ａで構成される。受信部１４０Ａは、通信装置１００Ｂからの信号を受信し、信号処理部１１０Ａに出力する。信号処理部１１０Ａは、各種信号処理に加え、通信装置１００Ｂに送信する光信号の波長を設定する。具体的に、信号処理部１１０Ａは、波長と温度との対応関係を示す対応情報を参照可能である。信号処理部１１０Ａは、対応情報を参照することで、通信装置１００Ｂに送信する光信号の波長に対応する温度を取得し、取得した温度とするように温度コントローラ１２０Ａを設定する。温度コントローラ１２０Ａは、設定された温度となるように送信部１３０Ａを調整する。送信部１３０Ａは、例えば波長可変レーザであり、温度に応じた波長の光信号を送信する。 The communication device 100A is composed of a signal processing unit 110A, a temperature controller 120A, a transmitting unit 130A, and a receiving unit 140A. The receiving unit 140A receives a signal from the communication device 100B and outputs it to the signal processing unit 110A. In addition to various signal processes, the signal processing unit 110A sets the wavelength of the optical signal to be transmitted to the communication device 100B. Specifically, the signal processing unit 110A can refer to correspondence information indicating the correspondence between wavelength and temperature. By referring to the correspondence information, the signal processing unit 110A obtains the temperature corresponding to the wavelength of the optical signal to be transmitted to the communication device 100B, and sets the temperature controller 120A to the obtained temperature. The temperature controller 120A adjusts the transmitting unit 130A to the set temperature. The transmitting unit 130A is, for example, a wavelength-variable laser, and transmits an optical signal with a wavelength according to the temperature.
　通信装置１００Ｂは、信号処理部１１０Ｂ、温度コントローラ１２０Ｂ、送信部１３０Ｂ、および受信部１４０Ｂで構成される。受信部１４０Ｂは、通信装置１００Ａからの信号を受信し、信号処理部１１０Ｂに出力する。信号処理部１１０Ｂは、各種信号処理に加え、零分散からのずれ量Δλを求める。 The communication device 100B is composed of a signal processing unit 110B, a temperature controller 120B, a transmission unit 130B, and a reception unit 140B. The reception unit 140B receives a signal from the communication device 100A and outputs it to the signal processing unit 110B. In addition to various signal processing, the signal processing unit 110B calculates the deviation amount Δλ from zero dispersion.
　具体的に、信号処理部１１０Ｂは、受信した光信号の周波数スペクトルから受信した光信号の周波数倍以外のところで最初にノッチが出現したノッチ周波数を求める。ノッチ周波数とは周波数スペクトルの平均線の傾きがマイナスからプラスに変化する箇所で、かつ、送信信号の周波数倍以外のところである。図２は、ノッチ周波数ｆ０の一例を示す図である。図２において、横軸は周波数を示し、縦軸はパワーを示す。ノッチ周波数としてｆ０、ｆ１が示されているが、このうちの最初に出現しているのはｆ０であるため、最初にノッチが出現したノッチ周波数はｆ０となる。 Specifically, the signal processing unit 110B finds the notch frequency at which a notch first appears other than multiples of the frequency of the received optical signal from the frequency spectrum of the received optical signal. A notch frequency is a point where the slope of the average line of the frequency spectrum changes from negative to positive and is a point other than multiples of the frequency of the transmitted signal. Figure 2 is a diagram showing an example of a notch frequency f0. In Figure 2, the horizontal axis indicates frequency and the vertical axis indicates power. f0 and f1 are shown as notch frequencies, but since f0 is the first of these to appear, the notch frequency at which the notch first appears is f0.
　なお、ｆ０を求める際、送信信号をＢｔＢで送った際のスペクトルのデータを事前に持っておき、ファイバ伝送後のスペクトルとの差分をとって最小値を求めることで、より精度よくf0を求めてもよい。なお、上記差分とは、縦軸の単位がPower spectral density（dB/Hz）なので、dB同士の差分という意味である。他の求め方として、例えば周波数スペクトルの平均線を算出し、その傾きがマイナスからプラスに変化する箇所を求め、その中から送信信号の周波数倍以外のところで最小となる箇所をｆ０として求めることが可能である。 When calculating f0, it is possible to obtain more accurate f0 by obtaining in advance the spectrum data when the transmission signal is sent via BtB, and finding the minimum value by taking the difference with the spectrum after fiber transmission. Note that the above difference means the difference between dB, since the unit of the vertical axis is power spectral density (dB/Hz). Another way to find it is to calculate the average line of the frequency spectrum, find the point where the slope changes from negative to positive, and find the point that is minimum outside of multiples of the frequency of the transmission signal as f0.
　信号処理部１１０Ｂは、求めたノッチ周波数と、所定のチャープ値と、通信装置１００Ａと通信装置１００Ｂとの距離と、から分散を求め、求めた分散から零分散からのずれ量Δλを求める。 Signal processing unit 110B calculates the dispersion from the calculated notch frequency, a predetermined chirp value, and the distance between communication device 100A and communication device 100B, and calculates the deviation Δλ from zero dispersion from the calculated dispersion.
　分散は下記式１で求める。式１において、Ｄは分散を示し、αはチャープ値を示し、Ｌは、通信装置１００Ａと通信装置１００Ｂとの距離を示し、ｃは光速を示す。
Ｄ＝ｃ／（２（ｆ０）２λ２Ｌ）（１－（２／π）arctanα）…（式１）
ずれ量Δλは下記式２で求める。
Δλ＝Ｄ／０．０９２…（式２）
　なお、Δλ＝Ｄ／０．０９２における０．０９２に代えて、使用しているファイバの分散スロープの値を用いてもよく、また、標準化で規定されている分散スロープの値を用いてもよい。例えば標準シングルモードファイバは０．０７３～０．０９２の値であり、その平均値である０．０８２５などを用いても良い。この場合、Δλ＝Ｄ／０．０８２５となる。
　信号処理部１１０Ｂは、送信部１３０Ｂに、求まったずれ量Δλを通信装置１００Ａに送信させる。また、信号処理部１１０Ｂは、送信部１３０Ｂに、ノッチが出現しているか否かを示すノッチ出現情報を通信装置１００Ａに送信させる。 The dispersion is calculated by the following formula 1. In formula 1, D represents the dispersion, α represents the chirp value, L represents the distance between communication device 100A and communication device 100B, and c represents the speed of light.
D=c/(2(f0) 2 λ 2 L) (1-(2/π) arctanα)...(Formula 1)
The deviation amount Δλ is calculated by the following formula 2.
Δλ=D/0.092...(Formula 2)
Instead of 0.092 in Δλ=D/0.092, the value of the dispersion slope of the fiber being used may be used, or the value of the dispersion slope specified by standardization may be used. For example, the value of the dispersion slope of a standard single mode fiber is 0.073 to 0.092, and the average value of these values, such as 0.0825, may be used. In this case, Δλ=D/0.0825.
The signal processing unit 110B causes the transmitting unit 130B to transmit the determined deviation amount Δλ to the communication device 100A. In addition, the signal processing unit 110B causes the transmitting unit 130B to transmit notch appearance information indicating whether or not a notch has appeared to the communication device 100A.
　なお、ｎ番目（ｎ＝０，１，２,…)のノッチが出願する周波数をｆｎとしたとき、ｆｎにおけるＤを以下の式３で求めることもできる。
Ｄ＝ｃ／（２（ｆｎ）２λ２Ｌ）（１＋２ｎ－（２／π）arctanα）…（式３）
　また、ｎ＝0,1,2,…のそれぞれでＤを求めて、その平均値をとって推定精度を上げた値をＤとしてもよい。 When the frequency at which the nth notch occurs (n=0, 1, 2, . . . ) is denoted by fn, D at fn can also be calculated using the following equation 3.
D=c/(2(fn) 2 λ 2 L) (1+2n-(2/π)arctanα)...(Formula 3)
Also, D may be calculated for each of n=0, 1, 2, . . . and the average value may be taken as D to improve the estimation accuracy.
　なお、外部変調器を用いて変調を行ようにチャープ値αが小さいとき、αを無視することでより簡易な計算で求めてもよい。 In addition, when the chirp value α is small, such as when an external modulator is used for modulation, the calculation can be simplified by ignoring α.
　信号処理部１１０Ｂは、波長と温度との対応関係を示す対応情報を参照可能である。信号処理部１１０Ｂは、対応情報を参照することで、通信装置１００Ａに送信する光信号の波長に対応する温度を取得し、取得した温度とするように温度コントローラ１２０Ｂを設定する。温度コントローラ１２０Ｂは、設定された温度となるように送信部１３０Ｂを調整する。送信部１３０Ｂは、例えば波長可変レーザであり、温度に応じた波長の光信号を送信する。 The signal processing unit 110B can refer to correspondence information that indicates the correspondence relationship between wavelength and temperature. By referring to the correspondence information, the signal processing unit 110B obtains the temperature that corresponds to the wavelength of the optical signal to be transmitted to the communication device 100A, and sets the temperature controller 120B to the obtained temperature. The temperature controller 120B adjusts the transmitting unit 130B to the set temperature. The transmitting unit 130B is, for example, a tunable laser, and transmits an optical signal with a wavelength according to the temperature.
　通信装置１００Ａは、通信装置１００Ｂから、受信部１４０Ａによって、零分散からのずれ量Δλを受信する。信号処理部１１０Ａは、送信部１３０Ａによって送信される光信号の送信波長をλ＋Δλまたはλ－Δλに変化させる。例えば、ずれ量Δλを受信した場合、信号処理部１１０Ａは、まずλ＋Δλに波長を変化させる。λ＋Δλに波長を変化させて、ノッチが出現しない場合には、信号処理部１１０Ａは、そのままλ＋Δλを波長とする。λ＋Δλに波長を変化させてもノッチが出現する場合には、信号処理部１１０Ａは、λ－Δλに波長を変化させる。すなわち、信号処理部１１０Ａは、光信号の送信波長をλ＋Δλおよびλ－Δλのいずれか一方（例えば、λ＋Δλ）に変化させた場合においてもノッチが出現するときは、さらに他方（例えば、λ－Δλ）の送信波長に変化させる。 The communication device 100A receives the deviation Δλ from zero dispersion from the communication device 100B by the receiver 140A. The signal processor 110A changes the transmission wavelength of the optical signal transmitted by the transmitter 130A to λ+Δλ or λ-Δλ. For example, when the deviation Δλ is received, the signal processor 110A first changes the wavelength to λ+Δλ. If the wavelength is changed to λ+Δλ and a notch does not appear, the signal processor 110A keeps the wavelength at λ+Δλ. If a notch appears even when the wavelength is changed to λ+Δλ, the signal processor 110A changes the wavelength to λ-Δλ. In other words, if a notch appears even when the signal processor 110A changes the transmission wavelength of the optical signal to either λ+Δλ or λ-Δλ (for example, λ+Δλ), the signal processor 110A further changes the transmission wavelength to the other (for example, λ-Δλ).
　このようにすることで、光ファイバの零分散波長と送信波長とのずれを抑制可能となる。さらに、図１に示されるように、本実施形態では、ＯＴＤＲやミラーなどを用いることがないので、追加の設備が不要であるので、コストをかけることなく、また簡易な構成で光ファイバの零分散波長と送信波長とのずれを抑制可能となる。 In this way, it is possible to suppress the deviation between the zero dispersion wavelength of the optical fiber and the transmission wavelength. Furthermore, as shown in FIG. 1, this embodiment does not use an OTDR, mirrors, or the like, so no additional equipment is required, and it is possible to suppress the deviation between the zero dispersion wavelength of the optical fiber and the transmission wavelength without incurring costs and with a simple configuration.
　（変形例）
　図３は、合分波用デバイスを用いた光通信システムの変形例の構成を示す図である。光通信システム２０に示されるように、図１に示した構成との違いは、合分波用デバイスを用いた１心双方向の構成となっている点である。すなわち、通信装置１１００Ａは、合分波用デバイス１５０Ａを備える。送信部１３０Ａは、合分波用デバイス１５０Ａに光信号を出力する。また、受信部１４０Ａは、合分波用デバイス１５０Ａから光信号を受信する。同様に、通信装置１１００Ｂは、合分波用デバイス１５０Ｂを備える。送信部１３０Ｂは、合分波用デバイス１５０Ｂに光信号を出力する。また、受信部１４０Ｂは、合分波用デバイス１５０Ｂから光信号を受信する。なお、合分波用デバイスとして、例えばサーキュレータや、合分波用カプラなどが挙げられる。合分波用デバイスは波長無依存のものが望ましい。 (Modification)
FIG. 3 is a diagram showing the configuration of a modified example of an optical communication system using a multiplexing/demultiplexing device. As shown in the optical communication system 20, the difference from the configuration shown in FIG. 1 is that the configuration is a single-core bidirectional configuration using a multiplexing/demultiplexing device. That is, the communication device 1100A includes a multiplexing/demultiplexing device 150A. The transmitting unit 130A outputs an optical signal to the multiplexing/demultiplexing device 150A. The receiving unit 140A receives an optical signal from the multiplexing/demultiplexing device 150A. Similarly, the communication device 1100B includes a multiplexing/demultiplexing device 150B. The transmitting unit 130B outputs an optical signal to the multiplexing/demultiplexing device 150B. The receiving unit 140B receives an optical signal from the multiplexing/demultiplexing device 150B. Examples of the multiplexing/demultiplexing device include a circulator and a multiplexing/demultiplexing coupler. It is preferable that the multiplexing/demultiplexing device is wavelength independent.
　図３に示す光通信システム２０においても、光ファイバの零分散波長と送信波長とのずれを抑制可能となる。さらに、図３に示されるように、本実施形態では、ＯＴＤＲやミラーなどを用いることがないので、追加の設備が不要であるので、コストをかけることなく、また簡易な構成で光ファイバの零分散波長と送信波長とのずれを抑制可能となる。 In the optical communication system 20 shown in FIG. 3, it is also possible to suppress the deviation between the zero dispersion wavelength of the optical fiber and the transmission wavelength. Furthermore, as shown in FIG. 3, this embodiment does not use an OTDR or mirrors, so no additional equipment is required, and it is therefore possible to suppress the deviation between the zero dispersion wavelength of the optical fiber and the transmission wavelength without incurring costs and with a simple configuration.
　次に、光通信システム１０、２０における処理の流れについて説明する。図４Ａ、図４Ｂ、図４Ｃは、光通信システム１０における処理の流れを示すシーケンス図である。なお、このシーケンス図は、光通信システム２０における処理の流れを示すものでもある。 Next, the process flow in optical communication systems 10 and 20 will be described. Figures 4A, 4B, and 4C are sequence diagrams showing the process flow in optical communication system 10. Note that these sequence diagrams also show the process flow in optical communication system 20.
　図４Ａにおいて、通信装置１００Ａは、波長λで光信号を送信する（ステップＳ１０１）。なお、送信側のデータパターンは特に制限はなく、例えば０１信号やＰＲＢＳ信号でも可能である。また、変調方式も特に制限はなく、ＮＲＺ信号やＰＡＭ４信号でも可能である。通信装置１００Ｂは、光信号を受信する（ステップＳ１０２）。通信装置１００Ｂは、ノッチ周波数ｆ０を求め（ステップＳ１０３）、ずれ量Δλを求める（ステップＳ１０４）。通信装置１００Ｂは、ずれ量Δλとノッチ出現情報（あり）を通信装置１００Ａに送信する（ステップＳ１０５）。ノッチ出現情報（あり）とは、ノッチが出現したことを示す。一方、ノッチ出現情報（なし）とは、ノッチが出現しなかったことを示す。 In FIG. 4A, the communication device 100A transmits an optical signal with a wavelength λ (step S101). There are no particular restrictions on the data pattern on the transmitting side, and it can be, for example, a 01 signal or a PRBS signal. There are also no particular restrictions on the modulation method, and it can be an NRZ signal or a PAM4 signal. The communication device 100B receives the optical signal (step S102). The communication device 100B determines the notch frequency f0 (step S103), and determines the deviation amount Δλ (step S104). The communication device 100B transmits the deviation amount Δλ and notch appearance information (present) to the communication device 100A (step S105). The notch appearance information (present) indicates that a notch has appeared. On the other hand, the notch appearance information (absent) indicates that a notch has not appeared.
　通信装置１００Ａは、ずれ量Δλとノッチありを受信し（ステップＳ１０６）、送信波長をλ＋Δλに変更する（ステップＳ１０７）。通信装置１００Ｂは、光信号を受信する（ステップＳ１０８）。通信装置１００Ｂは、ノッチが出現したか否かを判定する（ステップＳ１０９）。 The communication device 100A receives the deviation amount Δλ and the presence of a notch (step S106) and changes the transmission wavelength to λ+Δλ (step S107). The communication device 100B receives the optical signal (step S108). The communication device 100B determines whether a notch has appeared (step S109).
　ステップＳ１０９において、ノッチが出願しなかったと判定した場合について、図４Ｂを用いて説明する。図４Ｂにおいて、通信装置１００Ｂは、ノッチ出現情報（なし）を通信装置１００Ａに送信する（ステップＳ２０１）。通信装置１００Ａは、ノッチなしを受信する（ステップＳ２０２０）。この場合、送信波長をλ＋Δλのまま変更しない。 The case where it is determined in step S109 that a notch has not been applied will be described with reference to FIG. 4B. In FIG. 4B, communication device 100B transmits notch appearance information (none) to communication device 100A (step S201). Communication device 100A receives the absence of a notch (step S2020). In this case, the transmission wavelength is not changed to λ+Δλ.
　ステップＳ１０９において、ノッチが出願したと判定した場合について、図４Ｃを用いて説明する。図４Ｃにおいて、通信装置１００Ｂは、ずれ量Δλとノッチ出現情報（あり）を通信装置１００Ａに送信する（ステップＳ３０１）。通信装置１００Ａは、ずれ量Δλとノッチありを受信し（ステップＳ３０２）、送信波長をλ－Δλに変更する（ステップＳ３０３）。 The case where it is determined in step S109 that a notch has been applied will be described with reference to FIG. 4C. In FIG. 4C, communication device 100B transmits the amount of deviation Δλ and notch appearance information (present) to communication device 100A (step S301). Communication device 100A receives the amount of deviation Δλ and the presence of a notch (step S302), and changes the transmission wavelength to λ-Δλ (step S303).
　上述した実施形態では、温度コントローラを用いて波長を変更したが、これに限らない。例えば、図５、６に示される構成であっても本実施形態を適用できる。図５は、電流コントローラ１６０Ａと波長可変レーザ１７０Ａを用いた構成例を示す図である。図５の構成において、信号処理部１１０Ａは、波長と電流との対応関係を示す対応情報を参照可能である。信号処理部１１０Ａは、対応情報を参照することで、通信装置１００Ａに送信する光信号の波長に対応する電流を取得し、取得した電流で波長可変レーザ１７０Ａを印加するように電流コントローラ１６０Ａを設定する。電流コントローラ１６０Ａは、設定された電流で波長可変レーザ１７０Ａを印加する。 In the above-described embodiment, the wavelength is changed using a temperature controller, but this is not limiting. For example, this embodiment can be applied to the configurations shown in Figs. 5 and 6. Fig. 5 is a diagram showing an example configuration using a current controller 160A and a tunable laser 170A. In the configuration of Fig. 5, the signal processing unit 110A can refer to correspondence information indicating the correspondence between wavelength and current. By referring to the correspondence information, the signal processing unit 110A obtains a current corresponding to the wavelength of the optical signal to be transmitted to the communication device 100A, and sets the current controller 160A to apply the obtained current to the tunable laser 170A. The current controller 160A applies the set current to the tunable laser 170A.
　図６は、波長λ１～λｍまでの各々の波長を発信可能なレーザを含むアレイレーザ１８０Ａと合波器１９０Ａを用いた構成例を示す図である。図６の構成において、信号処理部１１０Ａは、所望の波長に対応する発振レーザを選択し、選択された発振レーザで信号を構成するようにアレイレーザ１８０Ａを設定する。アレイレーザ１８０Ａは、設定された発振レーザを駆動し、これにより生じた光信号は合波器１９０Ａによって合波され、対向装置に光信号が送信される。 FIG. 6 is a diagram showing an example configuration using an array laser 180A including lasers capable of emitting each of the wavelengths λ1 to λm, and a multiplexer 190A. In the configuration of FIG. 6, the signal processing unit 110A selects an oscillation laser corresponding to the desired wavelength, and sets the array laser 180A so that a signal is generated by the selected oscillation laser. The array laser 180A drives the set oscillation laser, and the optical signal generated by this is multiplexed by the multiplexer 190A, and the optical signal is transmitted to the opposing device.
　このように、波長の変更方法は、どのようなものであってもよい。また、本実施形態は、光ファイバの零分散波長と送信波長の範囲が重なっていれば適用可能（１３００～１３２４ｎｍの波長に限定されない）である。 As such, any method of changing the wavelength may be used. Furthermore, this embodiment is applicable as long as the zero dispersion wavelength of the optical fiber and the range of the transmission wavelength overlap (not limited to wavelengths between 1300 and 1324 nm).
　以上説明した実施形態によれば、光ファイバの零分散波長と送信波長とのずれを抑制することが可能となる。これにより、本実施形態を適用しない場合と比較して、通信可能な距離を拡大することが可能となる。なお、上記実施形態では、送信側を通信装置１００Ａとして説明したが、通信装置１００Ｂも通信装置１００Ａと同様の構成であることから、通信装置１００Ｂも光ファイバの零分散波長と送信波長とのずれを抑制することが可能となる。 According to the embodiment described above, it is possible to suppress the deviation between the zero dispersion wavelength of the optical fiber and the transmission wavelength. This makes it possible to extend the communication distance compared to when this embodiment is not applied. Note that in the above embodiment, the transmitting side is described as communication device 100A, but since communication device 100B has the same configuration as communication device 100A, communication device 100B can also suppress the deviation between the zero dispersion wavelength of the optical fiber and the transmission wavelength.
　以上説明した実施形態において、信号処理部１１０Ａ、１１０Ｂは、ＣＰＵ（Central Processing Unit）等のプロセッサーとメモリーとを用いて構成されてもよい。この場合、信号処理部１１０Ａ、１１０Ｂは、プロセッサーがプログラムを実行することによって、信号処理部１１０Ａ、１１０Ｂとして機能する。なお、信号処理部１１０Ａ、１１０Ｂの各機能の全て又は一部は、ＡＳＩＣ（Application Specific Integrated Circuit）やＰＬＤ（Programmable Logic Device）やＦＰＧＡ（Field Programmable Gate Array）等のハードウェアを用いて実現されても良い。上記のプログラムは、コンピュータ読み取り可能な記録媒体に記録されても良い。コンピュータ読み取り可能な記録媒体とは、例えばフレキシブルディスク、光磁気ディスク、ＲＯＭ、ＣＤ－ＲＯＭ、半導体記憶装置（例えばＳＳＤ：Solid State Drive）等の可搬媒体、コンピュータシステムに内蔵されるハードディスクや半導体記憶装置等の記憶装置である。上記のプログラムは、電気通信回線を介して送信されてもよい。 In the above-described embodiment, the signal processing units 110A and 110B may be configured using a processor such as a CPU (Central Processing Unit) and a memory. In this case, the signal processing units 110A and 110B function as the signal processing units 110A and 110B by the processor executing a program. Note that all or part of the functions of the signal processing units 110A and 110B may be realized using hardware such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array). The above program may be recorded on a computer-readable recording medium. Examples of computer-readable recording media include portable media such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, and a semiconductor storage device (e.g., an SSD: Solid State Drive), and storage devices such as a hard disk and a semiconductor storage device built into a computer system. The above program may be transmitted via a telecommunications line.
　以上、この発明の実施形態について図面を参照して詳述してきたが、具体的な構成はこの実施形態に限られるものではなく、この発明の要旨を逸脱しない範囲の設計等も含まれる。 　Although an embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs that do not deviate from the gist of the present invention.
　本発明は、光ファイバで通信を行う光通信システムに適用可能である。 The present invention is applicable to optical communication systems that communicate using optical fibers.
１０、２０　光通信システム、１００Ａ、１００Ｂ　通信装置、１１０Ａ、１１０Ｂ　信号処理部、１２０Ａ、１２０Ｂ　温度コントローラ、１３０Ａ、１３０Ｂ　送信部、１４０Ａ、１４０Ｂ　受信部、１５０Ａ、１５０Ｂ　合分波用デバイス、１６０Ａ　電流コントローラ、１７０Ａ　波長可変レーザ、１８０Ａ　アレイレーザ、１９０Ａ　合波器、１１００Ａ、１１００Ｂ　通信装置 10, 20 Optical communication system, 100A, 100B Communication device, 110A, 110B Signal processing unit, 120A, 120B Temperature controller, 130A, 130B Transmitter, 140A, 140B Receiver, 150A, 150B Multiplexer/demultiplexer device, 160A Current controller, 170A Tunable laser, 180A Array laser, 190A Multiplexer, 1100A, 1100B Communication device

Claims (8)

  1. 　第１通信装置と第２通信装置とを含む光通信システムであって、
    　前記第１通信装置は、
    　送信波長λの光信号を前記第２通信装置に送信する第１送信部と、
    　前記第２通信装置から、零分散からのずれ量Δλを受信する第１受信部と、
    　前記第１送信部によって送信される光信号の送信波長をλ＋Δλまたはλ－Δλに変化させる第１信号処理部と、
    　を備え、
    　前記第２通信装置は、
    　前記第１通信装置から光信号を受信する第２受信部と、
    　受信した光信号の周波数スペクトルから受信した光信号の周波数倍以外のところで最初にノッチが出現したノッチ周波数を求め、求めたノッチ周波数と、所定のチャープ値と、前記第１通信装置と前記第２通信装置との距離と、から分散を求め、求めた分散から零分散からのずれ量Δλを求める第２信号処理部と、
    　ずれ量Δλを前記第１通信装置に送信する第２送信部と、
    　を備えた光通信システム。     An optical communication system including a first communication device and a second communication device,
    The first communication device is
    a first transmitter for transmitting an optical signal having a transmission wavelength λ to the second communication device;
    a first receiving unit that receives a deviation amount Δλ from zero dispersion from the second communication device;
    a first signal processing unit that changes the transmission wavelength of the optical signal transmitted by the first transmitting unit to λ+Δλ or λ−Δλ;
    Equipped with
    The second communication device is
    A second receiving unit that receives an optical signal from the first communication device;
    a second signal processing unit that determines a notch frequency at which a notch first appears at a frequency other than a multiple of the received optical signal from the frequency spectrum of the received optical signal, determines dispersion from the determined notch frequency, a predetermined chirp value, and a distance between the first communication device and the second communication device, and determines a deviation Δλ from zero dispersion from the determined dispersion;
    a second transmission unit that transmits the deviation amount Δλ to the first communication device;
    An optical communication system comprising:
  2. 　前記第２送信部は、ノッチが出現しているか否かを示すノッチ出現情報をさらに送信する請求項１に記載の光通信システム。 The optical communication system of claim 1, wherein the second transmitter further transmits notch appearance information indicating whether a notch appears.
  3. 　前記第１信号処理部は、前記第１送信部によって送信される光信号の送信波長をλ＋Δλおよびλ－Δλのいずれか一方に変化させた場合においてもノッチが出現するときは、さらに他方の送信波長に変化させる請求項２に記載の光通信システム。 The optical communication system of claim 2, wherein the first signal processing unit further changes the transmission wavelength of the optical signal transmitted by the first transmitting unit to either λ+Δλ or λ-Δλ when a notch appears.
  4. 　送信装置と受信装置とを含む光通信システムにおける前記送信装置であって、
    　送信波長λの光信号を前記受信装置に送信する送信部と、
    　前記受信装置から、零分散からのずれ量Δλを受信する受信部と、
    　前記送信部によって送信される光信号の送信波長をλ＋Δλまたはλ－Δλに変化させる信号処理部と、
    　を備えた送信装置。     A transmitting device in an optical communication system including a transmitting device and a receiving device,
    a transmitter for transmitting an optical signal having a transmission wavelength λ to the receiving device;
    A receiving unit that receives a deviation amount Δλ from zero dispersion from the receiving device;
    a signal processing unit that changes the transmission wavelength of the optical signal transmitted by the transmitting unit to λ+Δλ or λ−Δλ;
    A transmitting device comprising:
  5. 　送信装置と受信装置とを含む光通信システムにおける前記受信装置であって、
    　前記送信装置から光信号を受信する受信部と、
    　受信した光信号の周波数スペクトルから受信した光信号の周波数倍以外のところで最初にノッチが出現したノッチ周波数を求め、求めたノッチ周波数と、所定のチャープ値と、前記送信装置と前記受信装置との距離と、から分散を求め、求めた分散から零分散からのずれ量Δλを求める信号処理部と、
    　ずれ量Δλを前記送信装置に送信する送信部と、
    　を備えた受信装置。     A receiving device in an optical communication system including a transmitting device and a receiving device,
    a receiving unit for receiving an optical signal from the transmitting device;
    a signal processing unit that determines a notch frequency at which a notch first appears at a frequency other than a multiple of the received optical signal from the frequency spectrum of the received optical signal, determines dispersion from the determined notch frequency, a predetermined chirp value, and a distance between the transmitting device and the receiving device, and determines a deviation Δλ from zero dispersion from the determined dispersion;
    a transmitter for transmitting the deviation amount Δλ to the transmitter;
    A receiving device comprising:
  6. 　第１通信装置と第２通信装置とを含む光通信システムの制御方法であって、
    　前記第１通信装置が、
    　送信波長λの光信号を前記第２通信装置に送信するステップと、
    　前記第２通信装置から、零分散からのずれ量Δλを受信するステップと、
    　送信される光信号の送信波長をλ＋Δλまたはλ－Δλに変化させるステップと、
    　を備え、
    　前記第２通信装置が、
    　前記第１通信装置から光信号を受信するステップと、
    　受信した光信号の周波数スペクトルから受信した光信号の周波数倍以外のところで最初にノッチが出現したノッチ周波数を求め、求めたノッチ周波数と、所定のチャープ値と、前記第１通信装置と前記第２通信装置との距離と、から分散を求め、求めた分散から零分散からのずれ量Δλを求めるステップと、
    　ずれ量Δλを前記第１通信装置に送信するステップと、
    　を備えた制御方法。     A control method for an optical communication system including a first communication device and a second communication device, comprising:
    The first communication device,
    transmitting an optical signal having a transmission wavelength λ to the second communication device;
    receiving a deviation Δλ from zero dispersion from the second communication device;
    changing the transmission wavelength of the optical signal to be transmitted to λ+Δλ or λ−Δλ;
    Equipped with
    The second communication device,
    receiving an optical signal from the first communication device;
    determining a notch frequency at which a notch first appears at a frequency other than a frequency multiple of the received optical signal from the frequency spectrum of the received optical signal, determining dispersion from the determined notch frequency, a predetermined chirp value, and a distance between the first communication device and the second communication device, and determining a deviation Δλ from zero dispersion from the determined dispersion;
    transmitting the deviation Δλ to the first communication device;
    A control method comprising:
  7. 　送信装置と受信装置とを含む光通信システムにおける前記送信装置の制御方法であって、
    　送信波長λの光信号を前記受信装置に送信するステップと、
    　前記受信装置から、零分散からのずれ量Δλを受信するステップと、
    　前記送信装置によって送信される光信号の送信波長をλ＋Δλまたはλ－Δλに変化させるステップと、
    　を備えた制御方法。     A method for controlling a transmitting device in an optical communication system including a transmitting device and a receiving device, comprising:
    transmitting an optical signal having a transmission wavelength λ to the receiving device;
    receiving a deviation Δλ from zero dispersion from the receiving device;
    changing a transmission wavelength of an optical signal transmitted by the transmitting device to λ+Δλ or λ−Δλ;
    A control method comprising:
  8. 　送信装置と受信装置とを含む光通信システムにおける前記受信装置の制御方法であって、
    　前記送信装置から光信号を受信するステップと、
    　受信した光信号の周波数スペクトルから受信した光信号の周波数倍以外のところで最初にノッチが出現したノッチ周波数を求め、求めたノッチ周波数と、所定のチャープ値と、前記送信装置と前記受信装置との距離と、から分散を求め、求めた分散から零分散からのずれ量Δλを求めるステップと、
    　ずれ量Δλを前記送信装置に送信するステップと、
    　を備えた受信装置。     A method for controlling a receiving device in an optical communication system including a transmitting device and a receiving device, comprising:
    receiving an optical signal from the transmitting device;
    determining a notch frequency at which a notch first appears at a frequency other than a frequency multiple of the received optical signal from the frequency spectrum of the received optical signal, determining dispersion from the determined notch frequency, a predetermined chirp value, and a distance between the transmitting device and the receiving device, and determining a deviation Δλ from zero dispersion from the determined dispersion;
    transmitting the deviation amount Δλ to the transmitting device;
    A receiving device comprising:
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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005341392A (en) * 2004-05-28 2005-12-08 Fujitsu Ltd Optical transmission device, optical transmission system and dispersion compensation method
US20190319708A1 (en) * 2018-04-17 2019-10-17 Electronics And Telecommunications Research Institute Apparatus and method for equalization and compensation of chromatic dispersion in optical transmission

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3879802B2 (en) * 1998-03-30 2007-02-14 富士通株式会社 Setting method of signal light wavelength of optical transmission system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005341392A (en) * 2004-05-28 2005-12-08 Fujitsu Ltd Optical transmission device, optical transmission system and dispersion compensation method
US20190319708A1 (en) * 2018-04-17 2019-10-17 Electronics And Telecommunications Research Institute Apparatus and method for equalization and compensation of chromatic dispersion in optical transmission

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