WO2012119421A1 - 一种光放大装置、方法及无源光网络系统和设备 - Google Patents

一种光放大装置、方法及无源光网络系统和设备 Download PDF

Info

Publication number
WO2012119421A1
WO2012119421A1 PCT/CN2011/079029 CN2011079029W WO2012119421A1 WO 2012119421 A1 WO2012119421 A1 WO 2012119421A1 CN 2011079029 W CN2011079029 W CN 2011079029W WO 2012119421 A1 WO2012119421 A1 WO 2012119421A1
Authority
WO
WIPO (PCT)
Prior art keywords
optical signal
optical
signal
continuous
doped fiber
Prior art date
Application number
PCT/CN2011/079029
Other languages
English (en)
French (fr)
Inventor
周小平
彭桂开
钱银博
欧鹏
Original Assignee
华为技术有限公司
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 华为技术有限公司 filed Critical 华为技术有限公司
Priority to PCT/CN2011/079029 priority Critical patent/WO2012119421A1/zh
Priority to CN201180001862.0A priority patent/CN102893544B/zh
Publication of WO2012119421A1 publication Critical patent/WO2012119421A1/zh

Links

Images

Classifications

    • 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
    • H04B10/29—Repeaters
    • H04B10/291—Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form
    • H04B10/2912—Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form characterised by the medium used for amplification or processing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0278—WDM optical network architectures
    • H04J14/0282—WDM tree architectures

Definitions

  • the present invention relates to the field of access networks, and in particular, to an optical amplifying device, a method, and a passive optical network (Passive Optical) Network, PON) systems and equipment.
  • Passive Optical Passive Optical
  • PON systems generally include an optical line terminal (Optical Line Terminal, OLT), an optical distribution network for branching/coupling or multiplexing/demultiplexing (Optical Distribution) Network, ODN) and several Optical Network Units (ONUs).
  • OLT optical Line Terminal
  • ODN optical Distribution network
  • ONUs Optical Network Units
  • the transmission distance of PON and GPON is up to 20Km.
  • the tree topology is used.
  • the downlink data is transmitted by broadcast, and the uplink data is transmitted by time division multiplexing.
  • EDFA Erbium-doped fiber amplifier
  • the surge effect of EDFA is determined by its working principle.
  • the helium ions in the fiber transition to the pump state (lifetime 1us) under the action of pump light, and then quickly relax to metastable state; in the continuous pump Under the Pu, there are more and more metastable particles, so that the population number is reversed; when the light signal passes, the metastable particles are excited to the ground state, and a photon with the same light signal is released. Achieve light amplification.
  • the number of inverted particles of the EDFA is accumulated over a long period of time, and the gain is large.
  • FIG. 1a is a burst optical signal input to an EDFA
  • FIG. 1b is an output optical signal amplified by an EDFA. It can be seen that when the burst optical signal arrives, since the gain of the EDFA cannot be abruptly changed, the front end gain of the burst data is large, resulting in deformation of the data signal. Therefore, the above EDFA surge effect easily causes system error and degrades system performance.
  • an optical amplifying device comprising: a hybrid optical signal synthesizer for receiving a burst optical signal and a continuous optical signal, and synthesizing the burst optical signal and the continuous optical signal into a mixed light a signal; an erbium doped fiber amplifier for amplifying a mixed optical signal output by the hybrid optical signal synthesizer; wherein the continuous optical signal of the mixed optical signal is used to consume a partial inversion of the erbium doped fiber amplifier The particles are caused to maintain an equilibrium state of the inverted particles of the erbium doped fiber amplifier when the erbium doped fiber amplifier amplifies the burst optical signal in the mixed optical signal.
  • an optical line terminal comprising: a transmitter for transmitting a downlink continuous optical signal; and an optical amplifying device for transmitting a downlink continuous optical signal and the light distribution from the transmitter
  • An upstream burst optical signal of the network synthesizes the mixed optical signal and amplifies the mixed optical signal by an erbium doped fiber amplifier, wherein the continuous optical signal in the mixed optical signal is used to consume a portion of the erbium doped fiber amplifier Reversing the particles such that the erbium-doped fiber amplifier maintains an equilibrium state of the inverted particles of the erbium-doped fiber amplifier while amplifying the upstream burst optical signal in the mixed optical signal; the receiver is configured to receive the pass The ascending burst optical signal in the mixed optical signal amplified by the erbium-doped fiber amplifier.
  • a passive optical network system comprising an optical line terminal and a plurality of optical network units, the optical line terminals being connected to the plurality of optical network units through an optical distribution network, the optical lines
  • the terminal is configured to transmit a downlink continuous optical signal output by the optical line terminal to the multiple optical network units, and transmit an uplink burst optical signal output by the multiple optical network units to the optical line terminal, where
  • the optical line termination is an optical line termination as described above.
  • an optical amplification method comprising: receiving a burst optical signal and a continuous optical signal, and synthesizing the burst optical signal and the continuous optical signal into a mixed optical signal; using an erbium doped fiber amplifier Enlarging the mixed optical signal, wherein the continuous optical signal in the mixed optical signal is used to consume partially inverted particles of the erbium doped fiber amplifier, causing the erbium doped fiber amplifier to diverge in the mixed optical signal The inverted particles of the erbium doped fiber amplifier maintain an equilibrium state as the illuminating signal is amplified.
  • the mixed optical signal is amplified by the burst optical signal and the continuous optical signal, and then amplified by the erbium-doped fiber amplifier EDFA.
  • the signal consumption is maintained in an equilibrium state; when the burst optical signal is injected into the EDFA, only the equilibrium state of the number of inverted particles established by the continuous optical signal produces a very small disturbance, and does not cause a sudden change of the carrier, so It can effectively suppress the surge effect of the EDFA on the amplification of the burst optical signal, and solve the problem of system performance degradation caused by the EDFA surge effect.
  • Figure 1a is a schematic diagram of a burst optical signal
  • FIG. 1b is a schematic diagram of the burst optical signal shown in FIG. 1a after being amplified by an existing EDFA;
  • FIG. 2 is a structural block diagram of an optical amplifying device according to an embodiment of the present invention.
  • FIG. 3 is a schematic structural diagram of a PON system applicable to an optical amplifying device provided by the present invention
  • FIG. 4 is a structural block diagram of an optical amplifying device according to a first embodiment of the present invention applied to an optical line terminal of a PON system;
  • FIG. 5 is a structural block diagram of an optical amplifying device according to a second embodiment of the present invention applied to an optical line terminal of a PON system;
  • FIG. 6 is a flowchart of implementing an optical amplification method according to an embodiment of the present invention.
  • FIG. 7 is a flowchart of an implementation of an optical amplifying method according to a first embodiment of the present invention applied to an optical line terminal of a PON system;
  • FIG. 8 is a flowchart of implementing an optical amplifying method according to a second embodiment of the present invention applied to an optical line terminal of a PON system.
  • the mixed optical signal is synthesized by the mixed optical signal synthesizer, and the mixed optical signal is amplified by the erbium-doped optical fiber amplifier EDFA, due to the mixed optical signal.
  • the power of the continuous optical signal is relatively large relative to the power of the burst optical signal, and the inverted particle number of the EDFA is mostly consumed by the continuous optical signal and maintained in an equilibrium state; when the burst optical signal is injected into the EDFA, the burst optical signal It can only produce a very small disturbance to the equilibrium state of the inverted particle number, and does not cause a sudden change of the carrier, so it can effectively suppress the surge effect of the EDFA on the amplification of the sudden optical signal, and solve the surge effect due to the EDFA. A problem that causes system performance degradation.
  • the optical amplifying device includes: a hybrid optical signal synthesizer. 210 and erbium doped fiber amplifier 220.
  • the mixed optical signal synthesizer 210 is configured to receive the burst optical signal and the continuous optical signal, combine the burst optical signal and the continuous optical signal into a mixed optical signal, and output the mixed optical signal to the erbium doped fiber amplifier 220;
  • the erbium doped fiber amplifier 220 is for amplifying the mixed optical signal received from the hybrid optical signal synthesizer 210.
  • the burst optical signal and the continuous optical signal may have different wavelengths
  • the hybrid optical signal synthesizer 210 may be wavelength division multiplexed by transmitting the burst optical signal and the continuous optical signal of the different wavelengths.
  • the hybrid optical signal is synthesized in a manner.
  • the mixed optical signal synthesizer 210 may also output the continuous optical signal to an output channel of the burst optical signal, such that an output light of an output channel of the burst optical signal is the burst light. a mixed optical signal of the signal and the continuous optical signal.
  • the power of the continuous optical signal received by the hybrid optical signal synthesizer 210 is greater than the power of the burst optical signal, so that the continuous optical signal in the mixed optical signal can consume the erbium doped fiber.
  • the partially inverted particles of amplifier 220 maintain the inverted particles in the erbium doped fiber amplifier 220 in an equilibrium state, thereby suppressing the surge effects that may occur in amplifying the upstream burst optical signal.
  • the optical amplifying device provided by the embodiment of the present invention can be applied to a passive optical network (PON) system as shown in FIG.
  • the passive optical network system may include at least one optical line terminal (OLT), a plurality of optical network units (ONUs), and an optical distribution network (ODN).
  • OLT is connected to the plurality of ONUs in a point-to-multipoint manner through the ODN.
  • the direction from the OLT to the ONU is defined as a downlink direction
  • the direction from the ONU to the OLT is defined as an uplink direction.
  • the OLT adopts time division multiplexing (Time Division Multiplexing, The TDM) broadcasts downlink data to the multiple ONUs, and each ONU only receives data carrying its own identifier; and in the uplink direction, the multiple ONUs use time division multiple access (Time Division) Multiple Access,
  • the TDMA mode communicates with the OLT, and each ONU sends uplink data strictly according to the time slot allocated by the OLT.
  • the downlink optical signal sent by the OLT is a continuous optical signal
  • the uplink optical signal sent by the ONU is a burst optical signal.
  • the passive optical network system may be a communication network system that does not require any active devices to implement data distribution between the OLT and the ONU.
  • the OLT and the ONU Data distribution between the two can be achieved by passive optical devices (such as optical splitters) in the ODN.
  • the passive optical network system 100 can be an ITU-T Asynchronous Transfer Mode Passive Optical Network (ATM PON) system or Broadband Passive Optical Network (BPON) system defined by the G.983 standard, ITU-T Gigabit Passive Optical Network (GPON) system defined by G.984 standard, Ethernet Passive Optical Network (EPON) defined by IEEE 802.3ah standard, or next-generation passive optical network (NGA) PON, such as XGPON or 10G EPON, etc.).
  • ATM PON Asynchronous Transfer Mode Passive Optical Network
  • BPON Broadband Passive Optical Network
  • GPON Gigabit Passive Optical Network
  • EPON Ethernet Passive Optical Network
  • NGA next-generation passive optical network
  • the OLT is usually located in the central office (Central Office, CO), which can uniformly manage the plurality of ONUs and transfer data between the ONUs and an upper layer network (not shown).
  • the OLT can serve as the ONU and the upper layer network (such as the Internet, public switched telephone network (Public) Switched Telephone Network, The medium between PSTN)) forwards data received from the upper layer network to the ONU, and forwards data received from the ONU to the upper layer network.
  • the specific structural configuration of the OLT may vary depending on the specific type of the passive optical network 100.
  • the OLT may include a transmitter and a receiver, and the transmitter is used to The ONU sends a downlink continuous optical signal, and the receiver is configured to receive an uplink burst optical signal from the ONU, where the downlink optical signal and the uplink optical signal may be transmitted through the optical distribution network.
  • the ONUs may be distributed in a user-side location (such as a customer premises).
  • the ONU may be a network device for communicating with the OLT and a user, in particular, the ONU may serve as a medium between the OLT and the user, for example, the ONU may be from the Data received by the OLT is forwarded to the user, and data received from the user is forwarded to the OLT.
  • ONT optical Network Terminal
  • the ODN may be a data distribution system that may include fiber optics, optocouplers, optical splitters, and/or other devices.
  • the fiber, optocoupler, optical splitter, and/or other device may be a passive optical device, in particular, the fiber, optocoupler, optical splitter, and/or other
  • the device may be a device that distributes data signals between the OLT and the ONU without power support.
  • the ODN may also include one or more processing devices, such as optical amplifiers or relay devices (Relay) Device). Additionally, the ODN may specifically extend from the optical line termination 110 to the plurality of ONUs, but may be configured in any other point-to-multipoint configuration.
  • the optical amplifying device may be applied to a central optical line terminal in a PON system, where the continuous optical signal may be a downlink continuous optical signal output by a transmitter of the optical line terminal, and the The burst optical signal may be an uplink burst optical signal sent by the optical network unit, and the wavelengths of the downlink continuous optical signal and the uplink burst optical signal may be different.
  • the optical line terminal may use the same optical amplifying device to implement amplification of the uplink burst optical signal and the downlink continuous optical signal.
  • the optical line terminal may include a transmitter 11, an optical amplifying device 13, a wave demultiplexing device 17, a receiver 14, and an optical router device 15.
  • the transmitter 11 of the optical line terminal is configured to output a downlink continuous optical signal to the optical amplifying device 13.
  • the optical amplifying device 13 can amplify the uplink burst optical signal and the downlink continuous optical signal by the erbium-doped fiber amplifier EDFA to effectively suppress the surge effect of the EDFA on the burst optical signal, and the optical amplifying device shown in FIG. 2 can be used.
  • the optical amplifying device 13 may include a hybrid optical signal synthesizer 131 and an erbium doped fiber amplifier 132.
  • the hybrid optical signal synthesizer 131 may include a wavelength division multiplexing device 141 for transmitting an uplink burst optical signal received from the optical router unit 15 and a downlink continuous optical signal received from the transmitter 11. Wavelength division multiplexing is performed to achieve signal mixing, and a multiplexed optical signal (i.e., a mixed optical signal) obtained by wavelength division multiplexing is transmitted to the erbium doped fiber amplifier 132.
  • the wavelength division multiplexing device 141 may include a first input port, a second input port, and an output port, wherein the first input port is connected to the transmitter 11, and the second input port is connected to the optical router device 15
  • the output port is connected to an erbium doped fiber amplifier 132.
  • the downlink continuous optical signal is a first input port of the optical line terminal transmitter 11 outputted to the wavelength division multiplexing device 141, and the uplink burst optical signal is received by the optical router component 15 from an optical distribution network (not shown).
  • the multiplexed optical signal is transmitted to the erbium doped fiber amplifier 132 through the output port of the wavelength division multiplexing device 141.
  • the erbium doped fiber amplifier 132 is configured to amplify the multiplexed optical signal formed by wavelength division multiplexing of the input light by the wavelength division multiplexing device 141 in the mixed optical signal synthesizer 131, and output the amplified multiplexed optical signal.
  • the multiplexed optical signal synthesized by the WDM device 141 includes a downlink continuous optical signal and an uplink burst optical signal, wherein the downlink continuous optical signal is continuously present, so the downlink continuous optical signal can be
  • the inverted particles of the majority of the erbium doped fiber amplifier 132 are consumed to maintain the inverted particles of the erbium doped fiber amplifier 132 in an equilibrium state; when the upstream burst optical signal is injected into the erbium doped fiber amplifier 132 for amplification, the equilibrium state is maintained.
  • the inverted particles do not cause a sudden change in carriers, thereby suppressing the surge effect, and solving the problem of system performance degradation due to the EDFA surge effect.
  • the wave decomposition multiplexing device 17 may include an input port, a first output port, and a second output port, wherein the input port is connected to the optical amplifying device 15, the first output port is connected to the optical router device 15, the second The output port is connected to the receiver 14.
  • the wave decomposition multiplexing device 17 can be configured to receive the multiplexed optical signal output by the optical amplifying device 13 through an input port, and perform wave decomposition multiplexing on the multiplexed optical signal, thereby obtaining an amplified downlink continuous optical signal.
  • the optical router component 15 can be a three-port optical router component that includes a first port, a second port, and a third port, wherein the first port is coupled to a wave decomposition multiplexing device 17, and the second port is coupled to optical amplification
  • the device 15 is connected to the optical distribution network, and the optical router component 15 can be configured to receive the amplified downlink continuous optical signal demultiplexed by the wave decomposition multiplexing device 17 through the first port, and pass the The three ports output the downlink continuous optical signal to the optical distribution network, and simultaneously receive the uplink burst optical signal transmitted by the optical network unit through the optical distribution network by using the third port, and provide the uplink burst optical signal to the wave through the second port.
  • the multiplexing device 141 is divided.
  • the optical router component 15 functions to forward the downlink continuous optical signal to the optical distribution network, and forward the uplink burst optical signal from the optical distribution network to the wavelength division multiplexing device 141. Is the role of an optical route.
  • the optical router component 15 It may be a wavelength division multiplexing/demultiplexing device, or, in other alternative embodiments, the optical router component 15 may also be implemented with a circulator.
  • the optical line terminal may further include an optical isolator 12 connected between the optical amplifying device 13 and the wave demultiplexing device 17, the optical isolator 12 is used to block the optical signal reflected by the wave demultiplexing device 17 from entering the erbium doped fiber amplifier 132, affecting the amplification process of the burst optical signal.
  • an optical isolator 12 connected between the optical amplifying device 13 and the wave demultiplexing device 17, the optical isolator 12 is used to block the optical signal reflected by the wave demultiplexing device 17 from entering the erbium doped fiber amplifier 132, affecting the amplification process of the burst optical signal.
  • the optical line terminal may further adopt different optical amplifying devices to perform a method of downlink continuous optical signals and uplink burst optical signals.
  • the optical line terminal may include a transmitter 21, a continuous optical amplifier 22, an optical amplifying device 23, and a receiver 26.
  • the transmitter 21 of the optical line terminal is configured to output a downlink continuous optical signal to the continuous optical amplifier 22.
  • the continuous optical amplifier 22 is configured to amplify the downlink continuous optical signal transmitted from the transmitter 21 of the optical line terminal, and output the amplified downlink continuous optical signal to the optical amplifying device 23; specifically, the continuous optical amplifier 22 An erbium doped fiber amplifier EDFA can be used.
  • the optical amplifying device 23 can use an EDFA to amplify the uplink burst optical signal to effectively suppress the surge effect of the EDFA on the burst optical signal, and can adopt an optical amplifying device as shown in FIG. 2, for example, the light
  • the amplifying means 23 may include a hybrid optical signal synthesizer 231 and an erbium doped fiber amplifier 232.
  • the hybrid optical signal synthesizer 231 can include an optical router component 251 and a partial mirror 252 (Partial Reflection Mirror, PM).
  • the optical router component 251 can be a three-port optical router component including a first port, a second port, and a third port, wherein the first port is connected to the erbium-doped fiber amplifier 232, and the second port is connected to the continuous port.
  • the optical amplifier 22 is connected to a light distribution network (not shown) via a partial mirror 252.
  • the optical router unit 251 can receive the downlink continuous optical signal amplified by the continuous optical amplifier 22 through the second port, and output the amplified downlink continuous optical signal to the downlink continuous optical signal through the third port.
  • a partial mirror 252; and the optical router unit 251 can receive an uplink burst optical signal from the optical distribution network through the third port, and output the uplink burst optical signal through the first port
  • the erbium doped fiber amplifier 232 is applied.
  • the partial mirror 252 is configured to partially reflect the downlink continuous optical signal output by the optical router unit 251. In this embodiment, a part of the amplified downlink continuous optical signal output by the third port of the optical router unit 251 is transmitted through.
  • the partial mirror 252 is output to the optical distribution network, and the other portion is reflected back to the optical router unit 251 by the partial mirror 252, and the reflected signal of the downstream continuous optical signal thus formed is returned to the optical router unit 251, and
  • the reflected signal is also a continuous optical signal.
  • the optical router unit 251 can synthesize the reflected signal of the downlink continuous optical signal received by the third port and the uplink burst optical signal into a mixed optical signal.
  • the optical router component 251 can provide the reflected signal of the downlink continuous optical signal. And an output channel of the uplink burst optical signal, so that a mixed optical signal of the reflected signal and the uplink burst optical signal is obtained on an output channel of the uplink burst optical signal, and the The mixed optical signal is transmitted to an erbium doped fiber amplifier 232.
  • the optical router unit 251 can also be a wavelength division multiplexing/demultiplexing device WDM or a circulator.
  • the erbium doped fiber amplifier 232 is for amplifying the mixed optical signal output from the optical router unit 251, and the upstream burst optical signal in the amplified mixed optical signal is supplied to the receiver 26 in one step.
  • the reflected signal including the downlink continuous optical signal and the uplink burst optical signal are included in the mixed signal transmitted to the erbium-doped fiber amplifier 232 through the first port of the optical router device 251, wherein the reflected signal of the downlink continuous optical signal It is continuous and the power is much larger than the power of the uplink burst optical signal, so the reflected signal of the downlink continuous optical signal can consume the inverted particles of most of the erbium-doped fiber amplifier 232, so that the erbium-doped fiber amplifier 232 is reversed.
  • the particles maintain an equilibrium state; when the ascending burst optical signal is injected into the erbium-doped fiber amplifier 232 for amplification, the inverted particles of the maintained equilibrium state do not cause a sudden change of carriers, thereby suppressing the surge effect and solving the EDFA
  • the surge effect causes problems with system performance degradation.
  • the optical line terminal may further include a first optical isolator 24 connected between the optical amplifying device 23 and the downlink continuous optical amplifier 22 for continuous downlink
  • the amplified downstream optical signal output from the optical amplifier 22 is isolated by the reflected light formed by the optical router member 251.
  • the optical line terminal may further include a second optical isolator 25 coupled between the optical amplifying device 23 and the receiver 26 for amplifying the output from the optical amplifying device 23.
  • the reflected signal in the mixed optical signal is isolated to prevent it from affecting the reception of the upstream burst optical signal by the receiver 26.
  • the embodiment of the present invention further provides an optical amplification method based on the above optical amplifying device.
  • FIG. 6 shows an implementation flow of an optical amplification method provided by the present invention, and the optical amplification method may include:
  • step S601 receiving a burst optical signal and a continuous optical signal, and synthesizing the burst optical signal and the continuous optical signal into a mixed optical signal;
  • the mixed optical signal includes the burst optical signal and the continuous optical signal.
  • the burst optical signal and the continuous optical signal may have different wavelengths, and the mixed light may be synthesized by wavelength-multiplexing the burst optical signal and the continuous optical signal of the different wavelengths in step S601. signal.
  • the continuous optical signal may also be output to an output channel of the burst optical signal, such that an output light of an output channel of the burst optical signal is the burst optical signal and A mixed optical signal of a continuous optical signal.
  • the mixed optical signal is amplified using an erbium doped fiber amplifier.
  • the continuous optical signal in the mixed optical signal can consume partially inverted particles of the erbium doped fiber amplifier, maintaining the inverted particles in the erbium doped fiber amplifier in an equilibrium state, thereby suppressing the The surge effect that the upstream burst optical signal may amplify.
  • the optical amplification method can be applied to a central optical line terminal in a PON system, such as the optical line terminal shown in FIGS. 4 and 5.
  • the continuous optical signal may be a downlink continuous optical signal output by a transmitter of the optical line terminal, and the burst optical signal may be an uplink burst optical signal sent by the optical network unit.
  • FIG. 7 is a flowchart showing an implementation of an optical amplification method according to a first embodiment of the present invention.
  • the optical amplification method may include:
  • step S700 the optical router device receives the uplink burst optical signal from the optical distribution network and forwards it to the hybrid optical signal synthesizer, and the transmitter transmits the downlink continuous optical signal to the hybrid optical signal synthesizer.
  • the uplink burst optical signal may be provided by the user-side optical network unit, and output to the central optical line terminal through the optical distribution network, and forwarded by the optical router component to the hybrid optical signal synthesizer; downlink continuous light
  • the signal may be output directly to the hybrid optical signal synthesizer by a transmitter internal to the optical line termination.
  • the uplink burst optical signal and the downlink continuous optical signal have different wavelengths.
  • step S701 the hybrid optical signal synthesizer performs wavelength division multiplexing on the uplink burst optical signal and the downlink continuous optical signal by the wavelength division multiplexing device, and transmits the wavelength division multiplexed multiplexed optical signal to the erbium doped fiber amplifier.
  • the first input port of the wavelength division multiplexing device receives the downlink continuous optical signal transmitted by the transmitter of the optical line terminal, and the second input port receives the uplink burst optical signal forwarded by the optical router device.
  • the wavelength division multiplexing device performs wavelength division multiplexing on the uplink burst optical signal received through the second input port and the downlink continuous optical signal received through the first input port, and transmits the complex after wavelength division multiplexing through the output port.
  • the optical signal is applied to the erbium doped fiber amplifier EDFA.
  • step S702 the erbium-doped fiber amplifier amplifies the uplink burst optical signal and the downlink continuous optical signal in the multiplexed optical signal, and transmits the amplified multiplexed optical signal to the wave decomposition multiplexing device.
  • the erbium-doped fiber amplifier amplifies the received wavelength division multiplexed optical signal, and transmits the amplified multiplexed optical signal to the wave decomposition multiplexing device, and receives the input through the input port of the wave decomposition multiplexing device.
  • the amplified multiplexed optical signal In practical applications, in order to support the long-distance, large-branch ratio passive optical network PON while maintaining the passive characteristics of the optical distribution network ODN, the uplink burst optical signal is not relayed during transmission. Therefore, when the uplink burst optical signal reaches the optical line terminal through transmission, the optical power is relatively weak, which is far lower than the sensitivity of the receiver commonly used in the access network.
  • the erbium-doped fiber amplifier EDFA is added to the burst optical signal for burst amplification before entering the receiver.
  • the erbium-doped fiber amplifier EDFA is also used to compensate the downlink continuous optical signal; since the downlink continuous optical signal is not lost, the optical power of the downlink continuous optical signal is the optical line terminal.
  • the transmit power of the transmitter is much larger than the optical power of the uplink burst optical signal received by the optical line terminal.
  • the same erbium-doped fiber amplifier is used to simultaneously amplify the uplink and downlink optical signals.
  • the downlink continuous optical signal is always present, and the power is relatively large relative to the uplink burst optical signal,
  • the majority of the inverted particles of the erbium-doped fiber amplifier are consumed by the downstream continuous optical signal and maintained in an equilibrium state; when the upstream burst optical signal is simultaneously injected into the erbium-doped fiber amplifier, the power of the uplink burst optical signal is very small.
  • step S703 the wave decomposition multiplexing device demultiplexes the amplified multiplexed optical signal to obtain an amplified uplink burst optical signal and a downlink continuous optical signal, and respectively transmits the amplified And a downstream burst optical signal and a downlink continuous optical signal to a receiver of the optical line terminal and the optical router component.
  • the amplified multiplexed optical signal is output to an input port of the wave decomposition multiplexing device, and the wave decomposition multiplexing device performs wavelength decomposition multiplexing on the amplified multiplexed optical signal to obtain an amplified uplink. a burst optical signal and a downlink continuous optical signal, and transmitting the amplified downlink continuous optical signal to the optical router device through the first output port, and transmitting the obtained amplified uplink burst optical signal to the optical line terminal through the second output port Receiver.
  • step S704 the optical router device outputs the amplified downlink continuous optical signal to the optical distribution network.
  • the erbium doped fiber amplifier EDFA is a commercially available EDFA.
  • the devices used in the method include an erbium doped fiber amplifier EDFA, an optical isolator, an optical router device, and a wavelength division multiplexing device and a wave demultiplexing device for multiplexing and demultiplexing burst optical signals and continuous optical signals.
  • the optical line terminals are all placed at the central office end, wherein the optical router component may be a wavelength division multiplexing or demultiplexing device, or may be a circulator.
  • the uplink burst optical signal and the downlink continuous optical signal can use different wavelengths of the C-band to take full advantage of the excellent gain characteristics of the EDFA in the C-band.
  • FIG. 8 is a flowchart showing an implementation of an optical amplification method according to a second embodiment of the present invention.
  • the optical amplification method may include:
  • step S801 the continuous optical amplifier amplifies the downlink continuous optical signal transmitted by the transmitter of the optical line terminal, and outputs the amplified downlink continuous optical signal to the optical router device.
  • step S802 the optical router device outputs the downlink continuous optical signal to the optical distribution network via the partial mirror.
  • the partial mirror PM is first entered, wherein 3%-15% The downstream continuous optical signal is reflected back to the optical router component.
  • step S803 the optical router device receives the reflected signal of the downlink continuous optical signal returned by the partial mirror, and receives the uplink burst optical signal provided by the optical network unit from the optical distribution network.
  • step S804 the optical router device outputs the reflected signal of the downlink continuous optical signal to the output channel of the uplink burst optical signal, thereby synthesizing and mixing the reflected signal with the uplink burst optical signal in the channel.
  • the optical signal is output to an erbium doped fiber amplifier.
  • the power of the reflected crosstalk optical signal of the downlink continuous optical signal that passes through the crosstalk into the uplink burst optical signal output channel of the optical router device is at least 10 dB greater than the power of the uplink burst optical signal in the channel.
  • a partial mirror of 10% optical power can be selected, so that the optical power of the 10% downlink optical signal is reflected back to the optical router by the partial mirror.
  • the optical router component may be a wavelength division multiplexing/demultiplexing device or a circulator.
  • the reflected signals of the downlink continuous optical signals reflected by the partial mirror are all output to the An output channel of the uplink burst optical signal; if the optical router component is a wavelength division multiplexing/demultiplexing device, the reflected signal is only due to the isolation of the wavelength division multiplexing/demultiplexing device An output channel that is partially entered into the upstream burst optical signal.
  • the wavelength division of the commercially available wavelength division multiplexing/demultiplexing device is generally 25 dB, and the power of the reflected signal entering the uplink burst optical signal channel is about -20 dBm (15 dBm - 10 dB - 25 dB).
  • step S805 the erbium-doped fiber amplifier amplifies the mixed optical signal outputted from the upstream burst optical signal output channel, and outputs the uplink burst optical signal in the amplified mixed optical signal to the optical line terminal. Receiver.
  • the erbium-doped fiber amplifier amplifies the mixed optical signal output from the uplink burst optical signal output channel, and therefore, the reflected signal of the downlink continuous optical signal enters the erbium-doped fiber amplifier together with the uplink burst optical signal. amplification.
  • the power of the uplink burst optical signal light is still small relative to the reflected signal. Therefore, the inverted particle number of the erbium-doped fiber amplifier is mostly consumed by the reflected signal of the downlink continuous optical signal, thereby maintaining an equilibrium state;
  • the uplink burst optical signal is simultaneously injected into the erbium-doped fiber amplifier, the abrupt change of the carrier is not caused.
  • the reflected signal can be used for clamp amplification of the burst optical signal, which can effectively suppress the EDFA.
  • the surge effect when the burst optical signal is amplified solves the problem of system performance degradation caused by the EDFA surge effect.
  • the amplified mixed optical signal output by the erbium-doped fiber amplifier can be isolated and transmitted to the receiver of the optical line terminal, wherein the isolation process can perform the reflected signal in the mixed optical signal. Isolation prevents the reflected signal from affecting the reception of the upstream burst optical signal of the receiver.

Landscapes

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

Abstract

一种光放大装置，包括混合光信号合成器，用于接收突发光信号和连续光信号，并将所述突发光信号和连续光信号合成混合光信号；掺铒光纤放大器，用于对所述混合光信号合成器输出的混合光信号进行放大；其中，所述混合光信号中的连续光信号用于消耗所述掺铒光纤放大器的部分反转粒子，使所述掺铒光纤放大器在对所述混合光信号中的突发光信号进行放大时所述掺铒光纤放大器的反转粒子维持平衡状态。还提供一种光放大方法以及无源光网络系统和设备。

Description

一种光放大装置、方法及无源光网络系统和设备 技术领域
本发明涉及接入网领域，尤其涉及一种光放大装置、方法及无源光网络（Passive Optical Network，PON）系统和设备。
 背景技术
目前，PON技术经过多年的发展，已经渐趋成熟，它以低廉的成本、巨大的带宽容量，在接入网领域得到广泛的应用。
PON系统一般包括一个光线路终端（Optical Line Terminal，OLT）、一个用于分支/耦合或者复用/解复用的光分配网（Optical Distribution Network，ODN）以及若干个光网络单元（Optical Network Unit，ONU）。典型的以太无源光网络（Ethernet Passive Optical Network，EPON）和千兆无源光网络（Gigabit-Capable PON，GPON）的传输距离最大为20Km，采用树形拓扑，下行数据使用广播方式传输，上行数据使用时分复用方式传输。
随着带宽需求的日益增大，网络成本的增长速度远高于带宽的增长速度，运营商的利润空间被不断压缩。延长PON网络的覆盖距离，增大PON系统所能支持的分支比，使得PON网络可以支持更多的用户，则分担给每个用户的网络成本就会有效降低，这逐渐成为PON网络发展的一种趋势。PON技术最主要的特征，在于它的ODN部分使用的是无源器件，使得维护成本非常低廉，但受限于光发射器件的发射光功率和光接收器件的接收灵敏度，目前商用的EPON和GPON的传输距离被限制在20Km，分支比限制在1:32以内。
为了提高系统功率预算，在PON系统中加入光放大器是一条较为简捷的途径。同时为了保持PON系统中ODN网络的无源特性以及降低ONU端的成本，可以将光放大器放在中心局端。光通信链路中，掺铒光纤放大器（Erbium Doped Fiber Amplifier，EDFA）是一种常用的光放大器。EDFA在1550nm波段具有较好的增益特性，噪声性能比较优秀，但是其对于突发光信号的响应存在如下所述的浪涌效应。
EDFA的浪涌效应是由它的工作原理决定的，光纤中的铒离子在泵浦光的作用下跃迁到泵浦态（寿命1us），然后迅速豫弛至亚稳态；在源源不断的泵浦下，亚稳态的粒子越来越多，从而实现粒子数反转；当光信号通过时，亚稳态的粒子受激辐射跃迁到基态，同时释放出一个与光信号相同的光子，来实现光放大。在突发环境下，当没有光信号输入时，EDFA的反转粒子数经过长时间的积累，增益较大。当突发光信号突然到来时，迅速消耗反转粒子，直到反转粒子的产生和消耗重新达到平衡进入稳定工作状态，因此，EDFA的增益也存在一个稳定的过程。如图1所示，图1a为输入EDFA的突发光信号，图1b为经过EDFA放大后的输出光信号。可以看出，当突发光信号到来时，由于EDFA的增益不能进行突变，突发数据的前端增益较大，从而导致数据信号的变形。因此，上述EDFA浪涌效应容易引起系统误码，劣化系统性能。
 技术问题
本发明的目的是提供一种光放大装置、方法和PON系统，以解决现有技术EDFA存在浪涌效应问题以及由于浪涌效应引起系统性能劣化的问题。
 技术解决方案
一方面，提供一种光放大装置，所述光放大装置包括：混合光信号合成器，用于接收突发光信号和连续光信号，并将所述突发光信号和连续光信号合成混合光信号；掺铒光纤放大器，用于对所述混合光信号合成器输出的混合光信号进行放大；其中，所述混合光信号中的连续光信号用于消耗所述掺铒光纤放大器的部分反转粒子，使所述掺铒光纤放大器在对所述混合光信号中的突发光信号进行放大时所述掺铒光纤放大器的反转粒子维持平衡状态。
另一方面，提供一种光线路终端，所述光线路终端包括：发射机，用于发射下行连续光信号；光放大装置，用于将所述发射机发射的下行连续光信号和来自光分配网络的上行突发光信号合成混合光信号，并通过掺铒光纤放大器对所述混合光信号进行放大，其中，所述混合光信号中的连续光信号用于消耗所述掺铒光纤放大器的部分反转粒子，使所述掺铒光纤放大器在对所述混合光信号中的上行突发光信号进行放大时所述掺铒光纤放大器的反转粒子维持平衡状态；接收机，用于接收经过所述掺铒光纤放大器放大的混合光信号中的上行突发光信号。
另一方面，提供一种无源光网络系统，所述系统包括光线路终端和多个光网络单元，所述光线路终端通过光分配网络连接至所述多个光网络单元，所述光线路终端用于将所述光线路终端输出的下行连续光信号传输至所述多个光网络单元，并将所述多个光网络单元输出的上行突发光信号传输至所述光线路终端，其中所述光线路终端为如上所述的光线路终端。
再一方面，提供一种光放大方法，所述方法包括：接收突发光信号和连续光信号，并将所述突发光信号和连续光信号合成混合光信号；利用掺铒光纤放大器对所述混合光信号进行放大，其中所述混合光信号中的连续光信号用于消耗所述掺铒光纤放大器的部分反转粒子，使所述掺铒光纤放大器在对所述混合光信号中的突发光信号进行放大时所述掺铒光纤放大器的反转粒子维持平衡状态。
 有益效果
在本发明实施例中，通过将突发光信号和连续光信号合成混合光信号，再通过掺铒光纤放大器EDFA对该混合光信号进行放大，由于EDFA的反转粒子数大部分被下行连续光信号消耗，维持在一个平衡状态；当突发光信号注入EDFA时，仅对连续光信号建立的反转粒子数的平衡状态产生一个可以非常微小的扰动，并没有引起载流子的突变，因此可以有效抑制EDFA对于突发光信号放大时的浪涌效应，解决由于EDFA浪涌效应引起系统性能劣化的问题。
 附图说明
图1a为突发光信号的示意图；
图1b为图1a所示突发光信号经过现有EDFA放大后的示意图；
图2为本发明实施例提供的光放大装置的结构框图；
图3为本发明提供的光放大装置可适用的PON系统的结构示意图；
图4为本发明第一实施例提供的光放大装置应用在PON系统的光线路终端的结构框图；
图5为本发明第二实施例提供的光放大装置应用在PON系统的光线路终端的结构框图；
图6为本发明实施例提供的光放大方法的实现流程图；
图7为本发明第一实施例提供的光放大方法应用在PON系统的光线路终端的实现流程图；
图8为本发明第二实施例提供的光放大方法应用在PON系统的光线路终端的实现流程图。
 本发明的实施方式
本发明所述的光放大装置中，通过混合光信号合成器将突发光信号和连续光信号合成混合光信号，再通过掺铒光纤放大器EDFA对该混合光信号进行放大，由于混合光信号中的连续光信号的功率相对于突发光信号的功率较大，EDFA的反转粒子数大部分被连续光信号消耗，维持在一个平衡状态；当突发光信号注入EDFA时，突发光信号只会对反转粒子数的平衡状态产生一个可以非常微小的扰动，并没有引起载流子的突变，因此可以有效抑制EDFA对于突发光信号放大时的浪涌效应，解决由于EDFA浪涌效应引起系统性能劣化的问题。
图2示出了本发明提供的光放大装置的结构框图，为了便于说明，仅示出了与本发明实施例相关的部分，在本实施例中，该光放大装置包括：混合光信号合成器210和掺铒光纤放大器220。
其中，混合光信号合成器210用于接收突发光信号和连续光信号，将所述突发光信号和连续光信号合成混合光信号，并输出所述混合光信号至掺铒光纤放大器220；
掺铒光纤放大器220用于对从所述混合光信号合成器210接收到的混合光信号进行放大。
比如，所述突发光信号和连续光信号可以具有不同的波长，且所述混合光信号合成器210是可以通过将所述不同波长的突发光信号和连续光信号进行波分复用的方式合成所述混合光信号。或者，所述混合光信号合成器210也可以将所述连续光信号输出至所述突发光信号的输出通道，从而使得所述突发光信号的输出通道的输出光为所述突发光信号和所述连续光信号的混合光信号。
在上述实施例中，所述混合光信号合成器210接收到的连续光信号的功率大于所述突发光信号的功率，因此所述混合光信号中的连续光信号可以消耗所述掺铒光纤放大器220的部分反转粒子，使所述掺铒光纤放大器220中的反转粒子维持平衡状态，从而抑制其在对所述上行突发光信号进行放大可能产生的浪涌效应。
本发明实施例提供的光放大装置可适用于如图3所示的无源光网络(PON)系统。请参阅图3，所述无源光网络系统可以包括至少一个光线路终端(OLT)、多个光网络单元(ONU)和一个光分配网络(ODN)。所述OLT通过所述ODN以点到多点的形式连接到所述多个ONU。其中，从所述OLT到所述ONU的方向定义为下行方向，而从所述ONU到所述OLT的方向定义为上行方向。在下行方向，所述OLT采用时分复用(Time Division Multiplexing, TDM)方式将下行数据广播给所述多个ONU，各个ONU只接收携带自身标识的数据；而在上行方向，所述多个ONU采用时分多址(Time Division Multiple Access, TDMA)的方式与所述OLT进行通信，每个ONU严格按照所述OLT分配的时隙发送上行数据。采用上述机制，所述OLT发送的下行光信号为连续光信号；而所述ONU发送的上行光信号为突发光信号。
所述无源光网络系统可以是不需要任何有源器件来实现所述OLT与所述ONU之间的数据分发的通信网络系统，比如，在具体实施例中，所述OLT与所述ONU之间的数据分发可以通过所述ODN中的无源光器件(比如分光器)来实现。并且，所述无源光网络系统100可以为ITU-T G.983标准定义的异步传输模式无源光网络(ATM PON)系统或宽带无源光网络(BPON)系统、ITU-T G.984标准定义的吉比特无源光网络(GPON)系统、IEEE 802.3ah标准定义的以太网无源光网络(EPON)、或者下一代无源光网络(NGA PON，比如XGPON或10G EPON等)。上述标准定义的各种无源光网络系统的全部内容通过引用结合在本申请文件中。
所述OLT通常位于中心局(Central Office，CO)，其可以统一管理所述多个ONU，并在所述ONU与上层网络(图未示)之间传输数据。具体来说，该OLT可以充当所述ONU与所述上层网络(比如因特网、公共交换电话网络(Public Switched Telephone Network, PSTN))之间的媒介，将从所述上层网络接收到的数据转发到所述ONU，以及将从所述ONU接收到的数据转发到所述上层网络。所述OLT的具体结构配置可能会因所述无源光网络100的具体类型而异，比如，在一种实施例中，所述OLT可以包括发射机和接收机，所述发射机用于向所述ONU发送下行连续光信号，所述接收机用于接收来自所述ONU的上行突发光信号，其中所述下行光信号和上行光信号可通过所述光分配网络进行传输。
所述ONU可以分布式地设置在用户侧位置(比如用户驻地)。所述ONU可以为用于与所述OLT和用户进行通信的网络设备，具体而言，所述ONU可以充当所述OLT与所述用户之间的媒介，例如，所述ONU可以将从所述OLT接收到的数据转发到所述用户，以及将从所述用户接收到的数据转发到所述OLT。应当理解，所述ONU的结构与光网络终端(Optical Network Terminal, ONT)相近，因此在本申请文件提供的方案中，光网络单元和光网络终端之间可以互换。
所述ODN可以是一个数据分发系统，其可以包括光纤、光耦合器、光分路器和/或其他设备。在一个实施例中，所述光纤、光耦合器、光分路器和/或其他设备可以是无源光器件，具体来说，所述光纤、光耦合器、光分路器和/或其他设备可以是在所述OLT和所述ONU之间分发数据信号是不需要电源支持的器件。另外，在其他实施例中，该ODN还可以包括一个或多个处理设备，例如，光放大器或者中继设备(Relay device)。另外，所述ODN具体可以从所述光线路终端 110延伸到所述多个ONU，但也可以配置成其他任何点到多点的结构。
作为本发明的一个实施例，所述光放大装置可以应用在PON系统中局端光线路终端，其中，所述连续光信号可以是光线路终端的发射机输出的下行连续光信号，而所述突发光信号可以是光网络单元发送的上行突发光信号，且所述下行连续光信号和所述上行突发光信号的波长可以是不同的。
在一种实施例中，所述光线路终端可以采用同一个光放大装置来实现上行突发光信号和下行连续光信号的放大。请参阅图4，所述光线路终端可以包括发射机11、光放大装置13、波分解复用器件17、接收机14和光路由器件15。
其中，光线路终端的发射机11用于输出下行连续光信号至所述光放大装置13。
光放大装置13可以通过掺铒光纤放大器EDFA对上行突发光信号和下行连续光信号进行放大而有效抑制EDFA对于突发光信号的浪涌效应，其可以采用如图2所示的光放大装置，比如，所述光放大装置13可以包括混合光信号合成器131和掺铒光纤放大器132。
混合光信号合成器131可以包括波分复用器件141，该波分复用器件141用于对从光路由器件15接收到的上行突发光信号和从发射机11接收到的下行连续光信号进行波分复用从而实现信号混合，并传输波分复用得到的复用光信号(即混合光信号)至掺铒光纤放大器132。
其中，所述波分复用器件141可以包括第一输入端口、第二输入端口和输出端口，其中所述第一输入端口连接至发射机11、所述第二输入端口连接至光路由器件15，所述输出端口连接至掺铒光纤放大器132。所述下行连续光信号是光线路终端的发射机11输出至波分复用器件141的第一输入端口，所述上行突发光信号是光路由器件15从光分配网络(图未示)接收到并路由至波分复用器件141的第二输入端口，所述复用光信号通过波分复用器件141的输出端口传输至掺铒光纤放大器132。
掺铒光纤放大器132用于对所述混合光信号合成器131中的波分复用器件141对输入光进行波分复用形成的复用光信号进行放大，并输出放大后的复用光信号至波分解复用器件17，由于波分复用器件141合成的复用光信号中包括下行连续光信号和上行突发光信号，其中下行连续光信号是连续存在的，因此下行连续光信号可以消耗大部分掺铒光纤放大器132的反转粒子，使掺铒光纤放大器132的反转粒子维持一个平衡状态；当上行突发光信号注入到掺铒光纤放大器132进行放大时，所述维持平衡状态的反转粒子不会引起载流子突变，从而抑制浪涌效应，解决了由于EDFA浪涌效应引起系统性能劣化的问题。
波分解复用器件17可以包括输入端口、第一输出端口和第二输出端口，其中所述输入端口连接至光放大装置15、所述第一输出端口连接至光路由器件15，所述第二输出端口连接至接收机14。所述波分解复用器件17可以用于通过输入端口接收由光放大装置13输出的复用光信号，并对该复用光信号进行波分解复用，从而得到经过放大后的下行连续光信号和上行突发光信号，并通过第二输出端口输出解复用得到的经过放大的下行连续光信号至光线路终端的接收机14，通过第一输出端口输出解复用得到的经过放大的上行突发光信号至光路由器件15。
光路由器件15可以是三端口光路由器件，其包括第一端口、第二端口和第三端口，其中所述第一端口连接至波分解复用器件17、所述第二端口连接至光放大装置15，所述第三端口连接至光分配网络，所述光路由器件15可以用于通过第一端口接收波分解复用器件17解复用得到的经过放大的下行连续光信号，并通过第三端口将该下行连续光信号输出至光分配网络，同时利用第三端口接收光网络单元经过光分配网络传输的上行突发光信号，并通过第二端口将该上行突发光信号提供给波分复用器件141。
在本实施例中，该光路由器件15的作用是将下行连续光信号转发到光分配网，而将来自光分配网的上行突发光信号转发到波分复用器件141，实际上起的是一个光路由的作用。在具体实施例中，由于下行连续光信号和上行突发光信号的波长不同，并且该下行连续光信号和上行连续光信号都可以同时承载在光分配网络的主干光纤进行传输，光路由器件15可以是波分复用/解复用器件，或者，在其他替代实施例中，所述光路由器件15也可以采用环行器实现。
进一步地，在一种实施例中，可选地，所述光线路终端还可进一步包括光隔离器12，其连接在所述光放大装置13和波分解复用器件17之间，光隔离器12用来阻隔波分解复用器件17反射回来的光信号进入掺铒光纤放大器132，影响突发光信号的放大过程。
在另一种实施例中，所述光线路终端还可以分别采用不同的光放大装置来进行下行连续光信号和上行突发光信号的方法。请参阅图5，所述光线路终端可以包括发射机21、连续光放大器22、光放大装置23和接收机26。
其中，光线路终端的发射机21用于输出下行连续光信号至连续光放大器22。
连续光放大器22用于对从所述光线路终端的发射机21发射的下行连续光信号进行放大，并输出放大后的下行连续光信号至光放大装置23；具体地，所述连续光放大器22可以采用掺铒光纤放大器EDFA。
所述光放大装置23可以采用EDFA对上行突发光信号进行放大而有效抑制EDFA对突发光信号的浪涌效应，其可以采用采用如图2所示的光放大装置，比如，所述光放大装置23可以包括混合光信号合成器231和掺铒光纤放大器232。
所述混合光信号合成器231可以包括光路由器件251和部分反射镜252（Partial reflection Mirror，PM）。
其中，光路由器件251可以是三端口光路由器件，其包括第一端口、第二端口和第三端口，其中所述第一端口连接至掺铒光纤放大器232、所述第二端口连接至连续光放大器22，所述第三端口通过部分反射镜252连接至光分配网络(图未示)。所述光路由器件251可以通过所述第二端口接收经过所述连续光放大器22放大的下行连续光信号，并通过所述第三端口将所述经过放大的下行连续光信号输出下行连续光信号至部分反射镜252；并且，所述光路由器件251还可以通过所述第三端口接收来自光分配网络的上行突发光信号，并通过所述第一端口将所述上行突发光信号输出给掺铒光纤放大器232。
部分反射镜252用于对所述光路由器件251输出的下行连续光信号进行部分反射，在本实施例中，光路由器件251第三端口输出的经过放大的下行连续光信号中其中一部分透过所述部分反射镜252输出至光分配网络，另一部分被所述部分反射镜252反射回所述光路由器件251，由此形成的该下行连续光信号的反射信号返回至光路由器件251，且所述反射信号也为连续光信号。
光路由器件251可以将所述第三端口接收到的下行连续光信号的反射信号以及上行突发光信号合成混合光信号，比如，光路由器件251可以将所述下行连续光信号的反射信号提供到所述上行突发光信号的输出通道，从而在所述上行突发光信号的输出通道得到所述反射信号和上行突发光信号的混合光信号，并通过所述第一端口将所述混合光信号传输至掺铒光纤放大器232。与前一个实施例相类似，所述光路由器件251也可以是波分复用/解复用器件WDM或者环行器。
掺铒光纤放大器232用于对从光路由器件251中输出的混合光信号进行放大，并且经过放大的混合光信号中的上行突发光信号经一步被提供至接收机26。
在本实施例中，由于通过光路由器件251的第一端口传输至掺铒光纤放大器232的混合信号中包括下行连续光信号的反射信号和上行突发光信号，其中下行连续光信号的反射信号是连续存在的，并且功率远大于上行突发光信号的功率，因此所述下行连续光信号的反射信号可以消耗大部分掺铒光纤放大器232的反转粒子，使掺铒光纤放大器232的反转粒子维持一个平衡状态；当上行突发光信号注入到掺铒光纤放大器232进行放大时，所述维持平衡状态的反转粒子不会引起载流子突变，从而抑制浪涌效应，解决了由于EDFA浪涌效应引起系统性能劣化的问题。
在一种实施例中，可选地，所述光线路终端还可进一步包括第一光隔离器24，其连接在所述光放大装置23和下行连续光放大器22之间，用于对下行连续光放大器22输出的放大后的下行连续光信号在所述光路由器件251反射后形成的反射光进行隔离处理。可选地，所述光线路终端还可进一步包括第二光隔离器25，其耦合在所述光放大装置23和接收机26之间，用于对从光放大装置23中输出的放大后的混合光信号中的反射信号进行隔离处理，避免其影响接收机26对上行突发光信号的接收。
基于上述光放大装置，本发明实施例还进一步提供一种光放大方法。图6示出了本发明提供的光放大方法的实现流程，所述光放大方法可以包括：
在步骤S601中，接收突发光信号和连续光信号，并将所述突发光信号和连续光信号合成混合光信号；
所述混合光信号包括所述突发光信号和所述连续光信号。比如，所述突发光信号和连续光信号可以具有不同的波长，且步骤S601中可以通过将所述不同波长的突发光信号和连续光信号进行波分复用的方式合成所述混合光信号。或者，所步骤S601中，也可以将所述连续光信号输出至所述突发光信号的输出通道，从而使得所述突发光信号的输出通道的输出光为所述突发光信号和所述连续光信号的混合光信号。
在步骤S602中，利用掺铒光纤放大器对所述混合光信号进行放大。其中，在所述混合光信号中的连续光信号可以消耗所述掺铒光纤放大器的部分反转粒子，使所述掺铒光纤放大器中的反转粒子维持平衡状态，从而抑制其在对所述上行突发光信号进行放大可能产生的浪涌效应。
作为本发明的一个实施例，所述光放大方法可以应用在PON系统中局端光线路终端，比如图4和图5所示的光线路终端。其中，所述连续光信号可以是光线路终端的发射机输出的下行连续光信号，而所述突发光信号可以是光网络单元发送的上行突发光信号。
下面结合在PON系统中的两个具体应用实例，详细介绍本发明实施例提供的光放大方法的具体实现过程。
图7示出了本发明第一实施例提供的光放大方法的实现流程，所述光放大方法可以包括：
在步骤S700中，光路由器件从光分配网络接收上行突发光信号并将其转发给混合光信号合成器，且发射机发射下行连续光信号至混合光信号合成器。
其中，上行突发光信号可以是由用户侧光网络单元提供，并通过光分配网络输出至局端光线路终端，并被所述光路由器件转发给所述混合光信号合成器；下行连续光信号可以是由光线路终端内部的发射机直接输出至所述混合光信号合成器。所述上行突发光信号和所述下行连续光信号具有不同的波长。
在步骤S701中，混合光信号合成器通过波分复用器件对上行突发光信号和下行连续光信号进行波分复用，并传输波分复用后的复用光信号至掺铒光纤放大器。
在本实施例中，波分复用器件的第一输入端口接收光线路终端的发射机传输的下行连续光信号，第二输入端口接收由光路由器件转发的上行突发光信号。波分复用器件将通过第二输入端口接收到的上行突发光信号和通过第一输入端口接收到的下行连续光信号进行波分复用，并通过输出端口传输波分复用后的复用光信号至掺铒光纤放大器EDFA。
在步骤S702中，所述掺铒光纤放大器对所述复用光信号中的上行突发光信号和下行连续光信号进行放大，并传输放大后的复用光信号至波分解复用器件。
在本实施例中，掺铒光纤放大器对接收到的波分复用光信号进行放大，并传输放大后的复用光信号至波分解复用器件，通过波分解复用器件的输入端口接收该放大后的复用光信号。在实际应用中，为了支持长距离、大分支比的无源光网络PON，同时保持光分配网ODN的无源特性，上行突发光信号在传输过程中，并没有进行中继放大。因此，上行突发光信号经过传输到达光线路终端时，光功率已经比较微弱，远远低于接入网常用接收机的灵敏度。因此，为了满足接收机的要求，在进入接收机之前，加入掺铒光纤放大器EDFA对上行突发光信号进行突发放大。同样，下行连续光信号在进入传输之前，也要使用掺铒光纤放大器EDFA对下行连续光信号进行功率补偿；由于下行连续光信号没有被损耗，因此下行连续光信号的光功率为光线路终端的发射机的发射功率，远远大于达到光线路终端接收的上行突发光信号的光功率。
基于上述原因，本实施例中，采用同一个掺铒光纤放大器对上下行光信号同时进行放大，在放大过程中，由于下行连续光信号一直存在，且功率相对于上行突发光信号较大，致使掺铒光纤放大器的反转粒子数大部分被下行连续光信号所消耗，维持在一个平衡状态；当上行突发光信号同时注入掺铒光纤放大器时，该上行突发光信号的功率非常小，仅对下行连续光信号建立的反转粒子数的平衡状态产生一个可以非常微小（可以忽略）的扰动，并没有引起载流子的突变，因此可以有效抑制掺铒光纤放大器EDFA对于上行突发光信号放大时的浪涌效应。因此，在掺铒光纤放大器EDFA中，下行连续光信号的存在，对上行突发光信号的EDFA放大起到增益钳制的作用，解决了由于EDFA浪涌效应引起系统性能劣化的问题。
在步骤S703中，所述波分解复用器件对所述放大后的复用光信号进行解复用，得到经过放大的上行突发光信号和下行连续光信号，并分别传输所述经过放大的上行突发光信号和下行连续光信号至光线路终端的接收机和所述光路由器件。
在本实施例中，经过放大的复用光信号被输出至波分解复用器件的输入端口，波分解复用器件对该经过放大的复用光信号进行波分解复用，得到经过放大的上行突发光信号和下行连续光信号，并通过第一输出端口传输经过放大的下行连续光信号至光路由器件，通过第二输出端口传输得到的经过放大的上行突发光信号至光线路终端的接收机。
在步骤S704中，光路由器件将经过放大的下行连续光信号输出至光分配网络。
另外，在本方法实施例中，掺铒光纤放大器EDFA是目前商用的EDFA。本方法中所用到的器件，包括掺铒光纤放大器EDFA、光隔离器、光路由器件以及用于突发光信号和连续光信号复用和解复用的波分复用器件和波分解复用器件，均放置在中心局端的光线路终端，其中，光路由器件可以是波分复用或者解复用器件，也可以是环行器。此外，在PON系统中，上行突发光信号和下行连续光信号可以使用C波段的不同波长，以充分利用EDFA在C波段增益特性优良的优势。
图8示出了本发明第二实施例提供的光放大方法的实现流程，所述光放大方法可以包括：
在步骤S801中，连续光放大器对光线路终端的发射机发射的下行连续光信号进行放大，并输出放大后的下行连续光信号至光路由器件。
在步骤S802中，光路由器件将所述下行连续光信号经过部分反射镜输出至光分配网络。
在本实施例中，在该下行连续光信号进入光分配网络之前，先进入部分反射镜PM，其中，3%-15% 的下行连续光信号被反射回光路由器件。
在步骤S803中，光路由器件接收由部分反射镜返回的下行连续光信号的反射信号，并从光分配网络接收由光网络单元提供的上行突发光信号。
在步骤S804中，光路由器件将所述下行连续光信号的反射信号输出至所述上行突发光信号的输出通道，从而将所述反射信号与所述通道中的上行突发光信号合成混合光信号，并输出至掺铒光纤放大器。
在本实施例中，经过串扰进入光路由器件的上行突发光信号输出通道的下行连续光信号的反射串扰光信号的功率至少比该通道中的上行突发光信号的功率大10dB。
在本实施例中，在下行连续光信号进入光分配网络传输之前，可以选用10%光功率的部分反射镜，这样，10%的下行连续光信号的光功率被部分反射镜反射回光路由器件。该光路由器件可以是波分复用/解复用器件，也可以是环行器，当该光路由器件是环行器时，则部分反射镜反射回的下行连续光信号的反射信号全部输出至所述上行突发光信号的输出通道；如果该光路由器件是波分复用/解复用器件，则由于波分复用/解复用器件的隔离度的存在，则所述反射信号只会由部分进入所述上行突发光信号的输出通道。目前商用的波分复用/解复用器件隔离度一般为25dB，则进入上行突发光信号通道的反射信号的功率约为-20dBm（15dBm-10dB-25dB）。
在步骤S805中，掺铒光纤放大器对从所述上行突发光信号输出通道输出的混合光信号进行放大，并将经过放大后的混合光信号中的上行突发光信号输出至光线路终端的接收机。
在本实施例中，掺铒光纤放大器对从上行突发光信号输出通道输出的混合光信号进行放大，因此，该下行连续光信号的反射信号与上行突发光信号一起进入掺铒光纤放大器进行放大。上行突发光信号光的功率相对于反射信号依然很小，因此，所述掺铒光纤放大器的反转粒子数大部分被下行连续光信号的反射信号所消耗，从而维持在一个平衡状态；当上行突发光信号同时注入掺铒光纤放大器时，不会引起载流子的突变，可见，所述反射信号可以对上行突发光信号的突发放大可以起到钳制作用，可以有效抑制EDFA对于突发光信号放大时的浪涌效应，解决了由于EDFA浪涌效应引起系统性能劣化的问题。
在具体实施例中，掺铒光纤放大器输出的放大后的混合光信号可以经过隔离处理之后再传输给光线路终端的接收机，其中所述隔离处理可以将所述混合光信号中的反射信号进行隔离，从而避免所述反射信号对接收机的上行突发光信号的接收造成影响。
以上所述仅为本发明的较佳实施例而已，并不用以限制本发明，凡在本发明的精神和原则之内所作的任何修改、等同替换和改进等，均应包含在本发明的保护范围之内。

Claims (20)

  1. 一种光放大装置，其特征在于，包括：
    混合光信号合成器，用于接收突发光信号和连续光信号，并将所述突发光信号和连续光信号合成混合光信号；
    掺铒光纤放大器，用于对所述混合光信号合成器输出的混合光信号进行放大；
    其中，所述混合光信号中的连续光信号用于消耗所述掺铒光纤放大器的部分反转粒子，使所述掺铒光纤放大器在对所述混合光信号中的突发光信号进行放大时所述掺铒光纤放大器的反转粒子维持平衡状态。
  2. 根据权利要求1所述的光放大装置，其特征在于，所述突发光信号和连续光信号具有不同波长，所述混合光信号合成器包括：
    波分复用器件，用于通过对接收到的突发光信号和连续光信号进行波分复用的方式合成所述混合光信号。
  3. 根据权利要求1所述的光放大装置，其特征在于，所述混合光信号合成器包括光路由器件和部分反射镜；
    所述光路由器件，用于将所述连续光信号输出至所述部分反射镜，接收所述连续光信号在所述部分反射镜发生部分反射而返回的反射信号，将所述连续光信号的反射信号提供至所述突发光信号的输出通道，并利用所述突发光信号的输出通道将所述连续光信号的反射信号和突发光信号合成所述混合光信号并输出至所述掺铒光纤放大器；
    所述部分反射镜，用于将所述光路由器件输出的连续光信号中的一部分反射回所述光路由器件。
  4. 根据权利要求3所述的光放大装置，其特征在于，所述光路由器件是波分复用/解复用器或者环行器。
  5. 一种光线路终端，其特征在于，包括：
    发射机，用于发射下行连续光信号；
    光放大装置，用于将所述发射机发射的下行连续光信号和来自光分配网络的上行突发光信号合成混合光信号，并通过掺铒光纤放大器对所述混合光信号进行放大，其中，所述混合光信号中的连续光信号用于消耗所述掺铒光纤放大器的部分反转粒子，使所述掺铒光纤放大器在对所述混合光信号中的上行突发光信号进行放大时所述掺铒光纤放大器的反转粒子维持平衡状态；
    接收机，用于接收经过所述掺铒光纤放大器放大的混合光信号中的上行突发光信号。
  6. 如权利要求5所述的光线路终端，其特征在于，所述上行突发光信号和所述下行连续光信号具有不同波长，且所述光放大装置包括波分复用器件，用于通过所述上行突发光信号和所述下行连续光信号进行波分复用的方式合成所述混合光信号，并将所述混合光信号输出至所述掺铒光纤放大器。
  7. 如权利要求6所述的光线路终端，其特征在于，还包括：
    波分解复用器件，用于将经过所述掺铒光纤放大器放大的混合光信号进行波分解复用而得到经过放大的上行突发光信号和下行连续光信号，并将所述上行突发光信号输出至所述接收机，将所述下行连续光信号输出至所述光分配网络。
  8. 如权利要求6所述的光线路终端，其特征在于，还包括：
    光隔离器，连接在所述掺铒光纤放大器和所述波分解复用器件之间，用于阻隔所述经过放大的混合光信号在所述波分解复用器件发生反射而形成的反射信号重新进入所述掺铒光纤放大器。
  9. 如权利要求5所述的光线路终端，其特征在于，所述光放大装置包括光路由器件和部分反射镜；
    所述光路由器件用于接收所述上行突发光信号和所述下行连续光信号，将所述下行连续光信号通过所述部分反射镜输出至光分配网络，接收所述下行连续光信号在所述部分反射镜发生部分反射而返回的反射信号，并通过所述突发光信号的输出通道将所述下行连续光信号的反射信号和所述上行突发光信号合成所述混合光信号并输出至所述掺铒光纤放大器；
    所述部分反射镜，用于将所述光路由器件输出的下行连续光信号中的一部分反射回所述光路由器件。
  10. 如权利要求9所述的光线路终端，其特征在于，所述光路由器件是波分复用/解复用器或者环行器。
  11. 如权利要求9所述的光线路终端，其特征在于，还包括：
    光隔离器，连接在所述接收机和所述掺铒光纤放大器之间，用于阻隔所述掺铒光纤放大器输出的经过放大的混合光信号中的下行连续光信号的反射信号进入所述接收机。
  12. 如权利要求11所述光线路终端，其特征在于，还包括：
    连续光放大器，连接在所述发射机和所述光放大装置之间，用于将发射机发射的下行连续光信号进行放大处理之后再提供给所述光放大装置。
  13. 一种无源光网络系统，其特征在于，包括光线路终端和多个光网络单元，所述光线路终端通过光分配网络连接至所述多个光网络单元，所述光线路终端用于将所述光线路终端输出的下行连续光信号传输至所述多个光网络单元，并将所述多个光网络单元输出的上行突发光信号传输至所述光线路终端，其中所述光线路终端为如权利要求5至12中任一项所述的光线路终端。
  14. 一种光放大方法，其特征在于，所述方法包括：
    接收突发光信号和连续光信号，并将所述突发光信号和连续光信号合成混合光信号；
    利用掺铒光纤放大器对所述混合光信号进行放大，其中所述混合光信号中的连续光信号用于消耗所述掺铒光纤放大器的部分反转粒子，使所述掺铒光纤放大器在对所述混合光信号中的突发光信号进行放大时所述掺铒光纤放大器的反转粒子维持平衡状态。
  15. 根据权利要求14所述的方法，其特征在于，所述突发光信号是光网络单元输出并经过光分配网络传输的上行突发光信号，所述连续光信号是光线路终端的发射机输出的下行连续光信号。
  16. 根据权利要求15所述的方法，其特征在于，将所述突发光信号和连续光信号合成混合光信号包括：
    采用波分复用的方式将接收到的突发光信号和连续光信号合成所述混合光信号，其中所述突发光信号和所述连续光信号具有不同波长。
  17. 根据权利要求16所述的方法，其特征在于，还包括：
    将经过所述掺铒光纤放大器放大的混合光信号进行波分解复用，得到经过放大的上行突发光信号和下行连续光信号，并将所述上行突发光信号输出至所述接收机，将所述下行连续光信号输出至光分配网络。
  18. 根据权利要求15所述的方法，其特征在于，将所述突发光信号和连续光信号合成混合光信号包括：
    从所述光分配网络接收所述上行突发光信号，并从所述光线路终端的发射机接收所述下行连续光信号；
    将所述下行连续光信号通过部分反射镜输出至所述光分配网络，并接收所述下行连续光信号在所述部分反射镜发生部分反射而返回的反射信号；
    通过所述突发光信号的输出通道将所述下行连续光信号的反射信号和所述上行突发光信号合成所述混合光信号并输出至所述掺铒光纤放大器。
  19. 根据权利要求18所述的方法，其特征在于，还包括：
    将所述掺铒光纤放大器输出的经过放大的混合光信号中的上行突发光信号输出至所述光线路终端的接收机，并在对所述掺铒光纤放大器输出的经过放大的混合光信号中的下行连续光信号的反射信号进行隔离处理以阻隔其被所述接收机。
  20. 根据权利要求19所述方法，其特征在于，所述光线路终端的发射机发射的下行连续光信号在被合成所述混合光信号之前经过放大处理。
PCT/CN2011/079029 2011-08-29 2011-08-29 一种光放大装置、方法及无源光网络系统和设备 WO2012119421A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/CN2011/079029 WO2012119421A1 (zh) 2011-08-29 2011-08-29 一种光放大装置、方法及无源光网络系统和设备
CN201180001862.0A CN102893544B (zh) 2011-08-29 2011-08-29 一种光放大装置、方法及无源光网络系统和设备

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2011/079029 WO2012119421A1 (zh) 2011-08-29 2011-08-29 一种光放大装置、方法及无源光网络系统和设备

Publications (1)

Publication Number Publication Date
WO2012119421A1 true WO2012119421A1 (zh) 2012-09-13

Family

ID=46797453

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2011/079029 WO2012119421A1 (zh) 2011-08-29 2011-08-29 一种光放大装置、方法及无源光网络系统和设备

Country Status (2)

Country Link
CN (1) CN102893544B (zh)
WO (1) WO2012119421A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110233672A (zh) * 2015-11-30 2019-09-13 谷歌有限责任公司 通信系统和方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109547107B (zh) * 2017-09-21 2023-08-04 中兴通讯股份有限公司 在无源光网络中控制下行光信号的方法、装置和设备

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101369085A (zh) * 2007-08-16 2009-02-18 聊城大学 多端口输入输出单纤双向掺铒光纤放大器
CN101383662A (zh) * 2008-10-30 2009-03-11 北京邮电大学 光网络中基于soa交叉增益调制效应的全光突发放大器
CN101572832A (zh) * 2008-04-28 2009-11-04 华为技术有限公司 一种无源光网络拉远的方法及设备和系统
CN101895345A (zh) * 2009-05-22 2010-11-24 华为技术有限公司 突发光信号放大方法、突发光放大器及系统和通信系统

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101369085A (zh) * 2007-08-16 2009-02-18 聊城大学 多端口输入输出单纤双向掺铒光纤放大器
CN101572832A (zh) * 2008-04-28 2009-11-04 华为技术有限公司 一种无源光网络拉远的方法及设备和系统
CN101383662A (zh) * 2008-10-30 2009-03-11 北京邮电大学 光网络中基于soa交叉增益调制效应的全光突发放大器
CN101895345A (zh) * 2009-05-22 2010-11-24 华为技术有限公司 突发光信号放大方法、突发光放大器及系统和通信系统

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110233672A (zh) * 2015-11-30 2019-09-13 谷歌有限责任公司 通信系统和方法
CN110233672B (zh) * 2015-11-30 2020-05-19 谷歌有限责任公司 通信系统和方法

Also Published As

Publication number Publication date
CN102893544A (zh) 2013-01-23
CN102893544B (zh) 2015-09-30

Similar Documents

Publication Publication Date Title
JP4898845B2 (ja) 双方向光増幅器装置
Shea et al. Long-reach optical access technologies
JP2880927B2 (ja) 光ファイバネットワークシステム
WO2013177957A1 (zh) 一种分布式基站信号传输系统及通信系统
KR101391265B1 (ko) 양방향 광학 증폭기
US7936991B2 (en) Optical line terminating apparatus and optical communication system
US8897639B2 (en) Methods and systems for increasing reach and/or split in passive optical networks
US20090208210A1 (en) Passive optical network remote protocol termination
US20100226649A1 (en) Multi-Fiber Ten Gigabit Passive Optical network Optical Line Terminal for Optical Distribution Network Coexistence with Gigabit Passive Optical Network
Reichmann et al. An eight-wavelength 160-km transparent metro WDM ring network featuring cascaded erbium-doped waveguide amplifiers
US8594502B2 (en) Method and apparatus using distributed raman amplification and remote pumping in bidirectional optical communication networks
EP2285019B1 (en) Optical communication system, apparatus and method
WO2006124532A2 (en) Method and system for mitigating raman crosstalk in an ethernet passive optical network
Fujiwara et al. Field trial of 100-km reach symmetric-rate 10G-EPON system using automatic level controlled burst-mode SOAs
WO2009012699A1 (fr) Appareil et procédé permettant d'amplifier des signaux optiques dans un résau optique passif et un terminal de ligne optique
US9699532B2 (en) Systems and methods of hybrid DWDM aggregation and extension for time division multiplexing passive optical networks
JP2010166279A (ja) 光通信システムおよび光集線装置
WO2012119421A1 (zh) 一种光放大装置、方法及无源光网络系统和设备
van Deventer et al. Architectures for 100-km 2048 split bidirectional SuperPONs from ACTS-PLANET
Van de Voorde et al. Network topologies for SuperPON
KR100813900B1 (ko) 기존의 수동형 광가입자 망에서 시분할다중방식 수동형광가입자 망 기반의 차세대 수동형 광가입자 망으로진화하는 방법 및 네트워크 구조
Kani et al. Current TDM-PON Technologies
KR20120074964A (ko) 10ｇ 이더넷 ｐｏｎ 중계 장치 및 그 시스템
WO2015184593A1 (zh) 发射机和用于发射光信号的方法
Appathurai et al. Measurement of tolerance to non-uniform burst powers in SOA amplified GPON systems

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 201180001862.0

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11860242

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 11860242

Country of ref document: EP

Kind code of ref document: A1