WO2023217131A1 - 光放大器、光放大的方法以及光纤通信系统 - Google Patents

光放大器、光放大的方法以及光纤通信系统 Download PDF

Info

Publication number
WO2023217131A1
WO2023217131A1 PCT/CN2023/092966 CN2023092966W WO2023217131A1 WO 2023217131 A1 WO2023217131 A1 WO 2023217131A1 CN 2023092966 W CN2023092966 W CN 2023092966W WO 2023217131 A1 WO2023217131 A1 WO 2023217131A1
Authority
WO
WIPO (PCT)
Prior art keywords
fiber
pump light
light
doped
optical amplifier
Prior art date
Application number
PCT/CN2023/092966
Other languages
English (en)
French (fr)
Inventor
何涛
姜恒云
邓宁
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
Publication of WO2023217131A1 publication Critical patent/WO2023217131A1/zh

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
    • H01S3/067—Fibre lasers
    • H01S3/06754—Fibre amplifiers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
    • H01S3/067—Fibre lasers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
    • H01S3/067—Fibre lasers
    • H01S3/06754—Fibre amplifiers
    • H01S3/06758—Tandem amplifiers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/09—Processes or apparatus for excitation, e.g. pumping
    • H01S3/091—Processes or apparatus for excitation, e.g. pumping using optical pumping
    • H01S3/094—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
    • 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
    • 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
    • H04B10/2916—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 using Raman or Brillouin amplifiers
    • 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
    • H04B10/293—Signal power control
    • H04B10/294—Signal power control in a multiwavelength system, e.g. gain equalisation
    • 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
    • H04B10/293—Signal power control
    • H04B10/294—Signal power control in a multiwavelength system, e.g. gain equalisation
    • H04B10/2941—Signal power control in a multiwavelength system, e.g. gain equalisation using an equalising unit, e.g. a filter
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0201—Add-and-drop multiplexing
    • H04J14/0202—Arrangements therefor

Definitions

  • the present application relates to the technical field of optical fiber communication, and in particular to an optical amplifier, an optical amplification method and an optical fiber communication system.
  • Optical fiber communication systems have the advantages of wide bandwidth, high capacity and low latency, and are widely used for the transmission of large amounts of data.
  • OSNR optical signal to noise ratio
  • optical amplifiers are usually used to compensate for fiber losses in optical fiber communication systems. The optical amplifier amplifies the signal while It will bring a certain amount of noise, which will also directly degrade the optical signal-to-noise ratio of the signal. Therefore, optical amplifiers need to develop towards wide bandwidth, low noise and ease of use.
  • doped optical fiber amplifiers are commonly used as optical amplifiers in optical fiber communication systems.
  • the optical amplifier is an Er-doped fiber amplifier (EDFA).
  • EDFA Er-doped fiber amplifier
  • a high inversion rate requires high-power pump light.
  • high-power pump light is input into a doped fiber amplifier, there will be residual pump light, and the remaining pump light will be dissipated in the form of heat, resulting in a relatively low utilization rate of the pump light of the optical amplifier.
  • This application provides an optical amplifier, an optical amplification method and an optical fiber communication system, which can improve the utilization rate of pump light.
  • this application provides an optical amplifier, which includes a first pump module, a first wavelength division multiplexing (WDM) and a doped optical fiber; the first pump module is used for , output Raman pump light; the first wavelength division multiplexer is used to couple the Raman pump light to the doped optical fiber; the doped optical fiber is used to absorb the Raman pump light, and input the The signal light of the optical amplifier is amplified and output, and the remaining pump light in the Raman pump light is output to the link fiber connected to the optical amplifier, and the remaining pump light is used as the pump light in the link fiber.
  • WDM wavelength division multiplexing
  • the pump light used by the optical amplifier is Raman pump light.
  • the first wavelength division multiplexer couples the Raman pump light to the doped fiber of the optical amplifier.
  • the doped fiber absorbs The Raman pump light amplifies and outputs the signal light input to the optical amplifier, and outputs the remaining pump light in the Raman pump light to the link fiber connected to the optical amplifier.
  • the link fiber uses the remaining pump light to perform Raman amplification of the signal light input to the link fiber.
  • the doped fiber and the link fiber share the Raman pump light.
  • the link fiber is relatively long and can absorb the remaining pump light, thereby improving the Utilization of pump light.
  • the Raman pump light is first input into the doped fiber, and part of it is absorbed.
  • the power of the remaining pump light is reduced compared to the power of the Raman pump light.
  • the power of the remaining pump light entering the link fiber is reduced to The acceptable range can solve the problem of Raman amplification of signal light by the link fiber and the problem of entering the link light.
  • the problem of excessive fiber pump light power eliminates the need for pump protection measures.
  • the transmission direction of the signal light is opposite to the transmission direction of the Raman pump light transmitted in the doped optical fiber; the transmission direction of the signal light is opposite to the transmission direction of the remaining pump light in the link fiber.
  • the direction of transmission is opposite.
  • the transmission direction of the signal light is opposite to the transmission direction of the pump light, which can realize reverse pumping of the link fiber and the optical amplifier, making the nonlinear cost of the link fiber relatively small.
  • the transmission direction of the signal light is the same as the transmission direction of the Raman pump light transmitted in the doped fiber; the transmission direction of the signal light is the same as the transmission direction of the remaining pump light in the link fiber.
  • the direction of transmission is the same.
  • the transmission direction of the signal light is the same as the transmission direction of the pump light, which enables co-directional pumping of the link fiber and the optical amplifier.
  • the doped optical fiber is fused to the link optical fiber, or connected through an optical fiber connector. In this way, a variety of connection methods for the doped optical fiber and the link optical fiber are provided.
  • the first pump module includes a plurality of pump units and a beam combining unit; the multiple pump units are used to output a plurality of pump lights of different wavelengths; the beam combining unit is used to combine the Multiple pump lights of different wavelengths are combined into one Raman pump light.
  • Raman pump light can be obtained by combining multiple pump lights with different wavelengths.
  • the wavelength range of the Raman pump light is 1400 nm to 1520 nm.
  • the optical amplifier further includes N doped optical fiber amplification modules, where N is an integer greater than or equal to 1; the 1st to Nth doped optical fiber amplification modules among the N doped optical fiber amplification modules are along the are arranged in sequence along the transmission direction of the signal light; the first wavelength division multiplexer is located between the N doped optical fiber amplification modules and the doped optical fiber.
  • the optical amplifier can be a multi-stage amplifier, which can make the gain of the signal light after passing through the optical amplifier meet the requirements.
  • the optical amplifier further includes a second pump module and a second wavelength division multiplexer; the second pump module is configured to output the first pump light; and the second wavelength division multiplexer is configured to , coupling the first pump light to the doped fiber; the doped fiber is used to absorb the Raman pump light and the first pump light, amplify and output the signal light, and the first pump The propagation direction of the pump light is opposite to that of the Raman pump light.
  • the optical amplifier adopts a bidirectional pumping method, which can make the gain of the signal light after passing through the optical amplifier meet the requirements.
  • the optical amplifier further includes an isolation module; the isolation module is used to prevent light transmitted in a reverse direction of the signal light transmission direction from passing through.
  • the isolation module prevents the light transmitted in the reverse direction of the signal light transmission direction from passing through, so that the light transmitted in the reverse direction of the signal light does not affect the optical amplifier.
  • this application provides a method of optical amplification, which method is applied to the optical amplifier described in the first aspect or any one of the first aspects.
  • the optical amplifier includes a first pump module, a first wavelength division complex
  • the method includes: the first pump module outputs Raman pump light to the first wavelength division multiplexer; and the first wavelength division multiplexer couples the Raman pump light to The doped optical fiber; the doped optical fiber absorbs the Raman pump light, amplifies and outputs the signal light input to the optical amplifier, and outputs the remaining pump light in the Raman pump light to the link optical fiber connected to the optical amplifier. pump light, and the remaining pump light serves as the pump light in the link fiber.
  • the doped fiber and the link fiber share the Raman pump light.
  • the link fiber is relatively long and can absorb the remaining pump light, thus It can improve the utilization rate of pump light.
  • the Raman pump light is first input into the doped fiber and is partially absorbed. The remaining pump light power is compared with the power of the Raman pump light. Reduce the power of the remaining pump light entering the link fiber to an acceptable range, which can solve the problem that the power of the pump light entering the link fiber is too high when the link fiber amplifies the signal light Raman, thus There is also no need for pump protection measures.
  • the transmission direction of the signal light is opposite to the transmission direction of the Raman pump light transmitted in the doped optical fiber; the transmission direction of the signal light is opposite to the transmission direction of the remaining pump light in the link fiber.
  • the direction of transmission is opposite.
  • the transmission direction of the signal light is opposite to the transmission direction of the pump light, which can realize reverse pumping of the link fiber and the optical amplifier, making the nonlinear cost of the link fiber relatively small.
  • this application provides an optical fiber communication system.
  • the optical fiber communication system includes a first network element, a second network element and at least one optical amplifier described in the first aspect or any one of the first aspects; the optical amplifier is located at between the first network element and the second network element.
  • Figure 1 is a schematic diagram of a traditional optical amplifier
  • Figure 2 is a schematic diagram of another traditional optical amplifier
  • Figure 3 is a schematic structural diagram of an optical fiber communication system provided by an exemplary embodiment of the present application.
  • Figure 4 is a schematic structural diagram of an optical amplifier provided by an exemplary embodiment of the present application.
  • Figure 5 is a schematic structural diagram of an optical amplifier provided by an exemplary embodiment of the present application.
  • Figure 6 is a schematic structural diagram of an optical amplifier provided by an exemplary embodiment of the present application.
  • Figure 7 is a schematic structural diagram of an optical amplifier provided by an exemplary embodiment of the present application.
  • Figure 8 is a schematic structural diagram of an optical amplifier provided by an exemplary embodiment of the present application.
  • Figure 9 is a schematic structural diagram of an optical amplifier provided by an exemplary embodiment of the present application.
  • Figure 10 is a schematic structural diagram of an optical amplifier provided by an exemplary embodiment of the present application.
  • Figure 11 is a schematic structural diagram of an optical amplifier provided by an exemplary embodiment of the present application.
  • Figure 12 is a schematic structural diagram of an optical amplifier provided by an exemplary embodiment of the present application.
  • Figure 13 is a schematic structural diagram of an optical amplifier provided by an exemplary embodiment of the present application.
  • Figure 14 is a schematic structural diagram of an optical amplifier provided by an exemplary embodiment of the present application.
  • Figure 15 is a schematic structural diagram of an optical amplifier provided by an exemplary embodiment of the present application.
  • Figure 16 is a schematic structural diagram of an optical amplifier provided by an exemplary embodiment of the present application.
  • Figure 17 is a schematic structural diagram of an optical amplifier provided by an exemplary embodiment of the present application.
  • Figure 18 is a schematic diagram of performance simulation and actual measurement results of an optical amplifier provided by an exemplary embodiment of the present application.
  • the first pump module 2. The first wavelength division multiplexer; 3. Doped fiber; 01. Link fiber;
  • Doped fiber amplification module 4.
  • VOA Variable optical attenuator
  • Raman effect refers to the scattering of frequency changes caused by the interaction between incident light and molecular motion when light passes through optical fiber media.
  • the Raman effect is also called Raman scattering.
  • DRA Disturbed Raman amplifier
  • the link fiber can also be called the transmission fiber.
  • Er-doped fiber amplifier a fiber amplifier in which erbium ions are doped into the core of the fiber through which the signal light passes.
  • Optical fiber communication systems have the advantages of large bandwidth, high capacity and low delay, and are widely used in the transmission of massive data. As the transmission rate continues to increase, the OSNR of the optical fiber communication system will decrease. In the optical fiber communication system, optical amplifiers are usually used to compensate for fiber losses. When the optical amplifier amplifies the signal, it will bring a certain amount of noise, which will directly Degrades the OSNR of the signal. Therefore, optical amplifiers need to develop towards wide bandwidth, low noise and ease of use.
  • doped optical fiber amplifiers are commonly used as optical amplifiers in optical fiber communication systems.
  • the optical amplifier is an EDFA
  • two cascaded EDFAs are shown, namely EDFA1 and EDFA2.
  • a high inversion rate requires high-power pump light.
  • high-power pump light is input into a doped fiber amplifier, there will be residual pump light, and the remaining pump light will be dissipated in the form of heat, resulting in a relatively low utilization rate of the pump light of the optical amplifier.
  • DRA and EDFA are used together as the line-side optical amplifier.
  • the name of the optical amplifier is Raman amplifier unit (RAU).
  • RAU Raman amplifier unit
  • the structure is shown in Figure 2.
  • DRA is cascaded with EDFA, and the Raman pump light is input into the link fiber through a wavelength division multiplexer to amplify the signal light.
  • the Raman pump light The power is relatively high, so DRA has safety risks such as fiber burning and human eye safety in application. Therefore, a series of safety measures need to be taken. For example, an interlock switch at the physical level realizes the safety protection of optical fiber shutting down the Raman pump source.
  • An optical time-domain reflectometer is integrated inside the optical amplifier to detect broken fibers or dirty fiber end faces to quickly shut down the Raman pump source.
  • connection between the optical amplifier and the link fiber is usually dirty, especially some organic matter is adsorbed on the connection, causing the high-power Raman pump light to burn out at the connection. Heat is generated everywhere, causing the optical fiber to burn out.
  • this application provides an optical amplifier.
  • the Raman pump light is first input into the doped fiber. After being partially absorbed by the doped fiber, the remaining pump light is input into the link fiber as the link fiber. Pump light.
  • the doped fiber and the link fiber share the Raman pump light, and the link fiber is relatively long and can fully absorb the remaining pump light, making the utilization rate of the pump light relatively high.
  • the power of the pump light entering the link fiber will be reduced, eliminating the need for pump safety protection related to Raman amplification.
  • the optical amplifier in the embodiment of the present application can be applied to an optical fiber communication system.
  • the optical fiber communication system includes a first network element 101, a second network element 102 and at least one optical amplifier.
  • the first network element 101 may be a sending device in the optical fiber communication system
  • the second network element 102 may be a receiving device in the optical fiber communication system.
  • the first network element 101 may be any two devices between the sending device and the receiving device in the optical fiber communication system.
  • the optical amplifier can be used as a relay amplifier of the optical fiber communication system, and the relay amplifier is located between the first network element 101 and the second network element 102 .
  • the optical amplifier can be used as a preamplifier of the optical fiber communication system.
  • the preamplifier is located before the second network element 102 and amplifies the signal light entering the second network element 102 .
  • the optical amplifier can be used as a post-amplifier of the optical fiber communication system.
  • the post-amplifier is located after the first network element 101 and amplifies the signal light output by the first network element 101.
  • optical amplifier in the embodiment of the present application is described below.
  • the optical amplifier includes a first pump module 1, a first wavelength division multiplexer 2 and a doped optical fiber 3.
  • the first pump module 1 is a light source that provides Raman pump light.
  • the first pump module 1 is connected to the first wavelength division multiplexer 2, the first wavelength division multiplexer 2 is connected to the doped optical fiber 3, and the doped optical fiber 3 is connected to the link fiber 01.
  • Link fiber 01 is the line side fiber.
  • the first pump module 1 outputs Raman pump light.
  • the first wavelength division multiplexer 2 couples the Raman pump light to the doped optical fiber 3 .
  • the doped optical fiber 3 absorbs the Raman pump light, amplifies the signal light input to the optical amplifier, and outputs it. After the Raman pump light passes through the doped fiber 3, there will be residual pump light.
  • the doped fiber 3 also outputs the remaining pump light in the Raman pump light to the link fiber 01.
  • Link fiber 01 absorbs the remaining pump light and Raman amplifies the signal light.
  • the doped fiber 3 and the link fiber 01 share the Raman pump light, which can make the utilization rate of the pump light relatively high.
  • link fiber 01 is much longer than the length of the doped fiber 3 and can fully absorb the remaining pump light.
  • the optical amplifier adopts reverse pumping mode, and the link fiber 01 also adopts reverse pumping mode.
  • the reverse pumping method refers to the pumping method in which the transmission directions of signal light and pump light are opposite.
  • Figure 4 exemplarily provides a schematic structural diagram of an optical amplifier.
  • the optical amplifier includes a first pump module 1, a first wavelength division multiplexer 2 and a doped optical fiber 3.
  • the first pump module 1 is a light source that provides Raman pump light.
  • the first wavelength division multiplexer 2 is a three-port device, the first pump module 1 is connected to the first port of the first wavelength division multiplexer 2, and the second port of the first wavelength division multiplexer 2 is connected to The doped optical fiber 3 is connected, and the third port of the first wavelength division multiplexer 2 can be used as the output port of the optical amplifier.
  • the doped optical fiber 3 is connected to the link optical fiber 01 , and the link optical fiber 01 is connected to the signal light input end of the doped optical fiber 3 .
  • the signal light passes through the link fiber 01, the doped fiber 3 and the first wavelength division multiplexer 2 in sequence.
  • the Raman pump light is output from the first pump module 1, it passes through the first wavelength division multiplexer 2, the doped fiber 3 and the link fiber 01 in sequence.
  • the first pump module 1 outputs Raman pump light.
  • the first wavelength division multiplexer 2 couples the Raman pump light to the doped optical fiber 3 .
  • the doped optical fiber 3 absorbs the Raman pump light, amplifies the signal light input to the doped optical fiber 3 and outputs it.
  • the signal light input to the doped fiber 3 is the signal light output from the link fiber 01.
  • the doped fiber 3 also outputs the remaining pump light in the Raman pump light to the link fiber 01.
  • Link fiber 01 is relatively long and can fully absorb the remaining pump light.
  • Raman amplifies the signal light input to link fiber 01.
  • the Raman amplified signal light is output to doped fiber 3, continues to be amplified, and finally passes through The first wavelength division multiplexer 2 performs output.
  • the optical amplifier uses a co-directional pumping method
  • the link fiber 01 also uses a co-directional pumping method.
  • the codirectional pumping method refers to the pumping method in which the signal light and the pump light transmit in the same direction.
  • Figure 5 exemplarily provides a schematic structural diagram of an optical amplifier. Referring to Figure 5, the optical amplifier includes a first pump module 1, a first wavelength division multiplexer 2 and a doped optical fiber 3.
  • the first wavelength division multiplexer 2 is a three-port device, the first pump module 1 is connected to the first port of the first wavelength division multiplexer 2, and the second port of the first wavelength division multiplexer 2 is connected to The doped optical fiber 3 is connected, and the third port of the first wavelength division multiplexer 2 can be used as the input port of the optical amplifier.
  • the doped optical fiber 3 is connected to the link optical fiber 01 , and the link optical fiber 01 is connected to the signal light output end of the doped optical fiber 3 .
  • the signal light passes through the first wavelength division multiplexer 2, the doped optical fiber 3 and the link optical fiber 01 in sequence.
  • the Raman pump light is output from the first pump module 1, it passes through the first wavelength division multiplexer 2, the doped fiber 3 and the link fiber 01 in sequence.
  • the first pump module 1 outputs Raman pump light.
  • the first wavelength division multiplexer 2 couples the Raman pump light to The optical fiber 3 is doped, and the received signal light is output to the doped optical fiber 3 .
  • the doped fiber 3 absorbs the Raman pump light, amplifies the signal light input to the doped fiber 3, and outputs the amplified signal light to the link fiber 01.
  • the doped fiber 3 also outputs the remaining pump light in the Raman pump light to the link fiber 01.
  • the link fiber 01 is relatively long and can fully absorb the remaining pump light, Raman amplifies the signal light input to the link fiber 01, and outputs the Raman amplified signal light.
  • the signal light transmitted in the optical amplifier is wavelength division multiplexing signal light.
  • Wavelength division multiplexing signal light includes signal light in multiple bands.
  • the wavelength range of the wavelength division multiplexing signal light may be 1520nm ⁇ 1630nm.
  • the optical amplifier may be an EDFA
  • the doped optical fiber 3 is at least doped with erbium ions.
  • the signal light may be conventional (C) band light, long (L) band light or C+L band light
  • the doped fiber 3 may be a single-mode erbium-doped fiber, a large Mode field erbium-doped fiber or double-clad erbium-doped fiber, etc.
  • the doped optical fiber 3 and the link optical fiber 01 are directly connected, the doped optical fiber 3 and the link optical fiber 01 are connected through fusion splicing, or the doped optical fiber 3 and the link optical fiber 01 are connected through an optical fiber connector.
  • the optical fiber connector can be any connector used to connect optical fibers, which is not limited in the embodiments of this application. Connecting through fusion splicing can reduce loss compared to connecting through fiber optic connectors.
  • the Raman pump light provided by the first pump module 1 includes pump light of different wavelengths.
  • the first pump module 1 includes a plurality of pump units 11 and a beam combining unit 12.
  • the plurality of pump units 11 are respectively connected to the beam combining unit 12, and the beam combining unit 12 is connected to the first beam combining unit 12.
  • Multiple pump units 11 can output multiple pump lights of different wavelengths. Each pump unit 11 outputs pump light of one wavelength. The power of the pump lights output by multiple pump units 11 may be the same or different. same.
  • the beam combining unit 12 combines a plurality of pump lights of different wavelengths into one beam of Raman pump light. The beam combining unit 12 outputs the Raman pump light to the first wavelength division multiplexer 2 .
  • Figure 6 takes the reverse pumping method as an example for description. The co-directional pumping method is similar and will not be described again here.
  • the polarization states of the two pump lights output by the two pump units 11 may be orthogonal, and the beam combining unit 12 may be Polarization combiner.
  • the pump unit 11 may be a semiconductor laser, a fiber laser, a solid laser, or the like.
  • the power of the Raman pump light can be set according to actual needs.
  • the power of the Raman pump light can be set so that the power of the remaining pump light does not burn the fiber.
  • the wavelength range of the Raman pump light is 1400nm ⁇ 1520nm.
  • the signal light is C-band light
  • the C-band Raman pump light is obtained by combining two pump lights in the range of 1400 nm to 1499 nm through the beam combining unit 12 .
  • the two pump light wavelengths are 1427nm and 1465nm.
  • the optical amplifier adopts a bidirectional pumping method, and the Raman pump light and the signal light transmit in opposite directions.
  • the optical fiber amplifier includes a first pump module 1, a first wavelength division multiplexer 2, a doped optical fiber 3, a second pump module 5 and a second wavelength division multiplexer 6.
  • the second pump module 5 can output the first pump light, and the first pump light may be a single-wavelength pump light.
  • the second pump module 5 is connected to the second wavelength division multiplexer 6 .
  • the second wavelength division multiplexer 6 is connected to the doped optical fiber 3, see the optical amplifier shown in Figure 7.
  • the second wavelength division multiplexer 6 receives the signal light input into the optical amplifier and outputs the signal light to the doped optical fiber 3 .
  • the second wavelength division multiplexer 6 also couples the first pump light into the doped optical fiber 3.
  • the transmission direction of the first pump light in the doped optical fiber 3 is the same as the transmission direction of the signal light in the doped optical fiber 3. .
  • the first wavelength division multiplexer 2 couples the Raman pump light into the doped optical fiber 3 , and the transmission direction of the Raman pump light in the doped optical fiber 3 is opposite to the transmission direction of the signal light in the doped optical fiber 3 .
  • the doped optical fiber 3 absorbs the Raman pump light and the first pump light, amplifies the signal light input into the doped optical fiber 3 , and outputs the amplified signal light to the first wavelength division multiplexer 2 .
  • Doped fiber 3 also outputs Raman pump to link fiber 01 The remaining pump light in the light.
  • Link fiber 01 is relatively long and can fully absorb the remaining pump light.
  • Raman amplifies the signal light input to link fiber 01 and outputs the Raman amplified signal light.
  • the Raman amplified signal light undergoes the second wavelength division
  • the multiplexer 6 outputs to the doped optical fiber 3, which continues to amplify the Raman amplified signal light, and outputs the amplified signal light to the first wavelength division multiplexer 2.
  • the first wavelength division multiplexer 2 transmits the amplified signal light.
  • the optical amplifier also adopts a bidirectional pumping method, and the transmission direction of the Raman pump light and the signal light is the same.
  • the optical fiber amplifier includes a first pump module 1, a first wavelength division multiplexer 2, a doped optical fiber 3, a second pump module 5 and a second wavelength division multiplexer 6.
  • the second pump module 5 can output the first pump light, and the first pump light may be a single-wavelength pump light.
  • the second pump module 5 is connected to the second wavelength division multiplexer 6 .
  • the second wavelength division multiplexer 6 is connected to the doped optical fiber 3, see the optical amplifier shown in Figure 8.
  • the first wavelength division multiplexer 2 receives the signal light input to the optical amplifier and outputs the signal light to the doped optical fiber 3 .
  • the first wavelength division multiplexer 2 also couples the Raman pump light into the doped fiber 3.
  • the transmission direction of the Raman pump light in the doped fiber 3 is the same as the transmission direction of the signal light in the doped fiber 3. .
  • the second wavelength division multiplexer 6 couples the first pump light into the doped optical fiber 3 , and the transmission direction of the first pump light in the doped optical fiber 3 is opposite to the transmission direction of the signal light in the doped optical fiber 3 .
  • the doped optical fiber 3 absorbs the Raman pump light and the first pump light, amplifies the signal light input into the doped optical fiber 3 , and outputs the amplified signal light to the second wavelength division multiplexer 6 .
  • the doped optical fiber 3 also outputs the remaining pump light in the Raman pump light to the second wavelength division multiplexer 6 .
  • the second wavelength division multiplexer 6 transmits the amplified signal light and the remaining pump light to the link optical fiber 01 .
  • the link fiber 01 is relatively long and can fully absorb the remaining pump light, Raman amplifies the signal light input to the link fiber 01, and outputs the Raman amplified signal light.
  • the optical amplifier further includes an isolation module 7 .
  • the isolation module 7 is located on the transmission path of the signal light output by the first wavelength division multiplexer 2, see the optical amplifier shown in Figure 9.
  • the isolation module 7 is located on the transmission path of the signal light output by the doped optical fiber 3, see the optical amplifier shown in Figure 10.
  • the isolation module 7 can prevent the light transmitted in the reverse direction of the signal light transmission direction from passing through.
  • the isolation module 7 may be an isolator (ISO).
  • the optical amplifier in order to flatten the gain spectrum of the signal light output by the optical amplifier, the optical amplifier further includes a gain flattening filter module 8 .
  • the gain flattening filter module 8 is located on the transmission path of the signal light output by the first wavelength division multiplexer 2, see the optical amplifier shown in Figure 11.
  • the gain flattening filter module 8 is located on the transmission path of the signal light output by the doped optical fiber 3, see the optical amplifier shown in Figure 12.
  • the gain flattening filter module 8 can be used to flatten filter the signal light output by the doped optical fiber 3 .
  • the gain flattening filter module 8 may be gain flattening filters (GFF).
  • the optical amplifier further includes an adjustable optical attenuator 9 .
  • the adjustable optical attenuator 9 is located on the transmission path of the signal light output by the first wavelength division multiplexer 2 .
  • the adjustable optical attenuator 9 is located on the transmission path of the signal light output by the doped optical fiber 3 .
  • the adjustable optical attenuator 9 can be used to attenuate the signal light output by the doped optical fiber 3 .
  • the optical amplifier when the optical amplifier includes an isolation module 7, a gain flat filter module 8 and an adjustable optical attenuator 9, the signal light output by the erbium-doped fiber 3 passes through the isolation module 7, the gain flat filter module 8 and the adjustable optical attenuator in sequence. Dimmable attenuator 9, see the optical amplifier shown in Figure 13.
  • the optical amplifier shown in Figure 13 uses Raman pump light and signal light in opposite transmission directions. For example, the Raman pump light in the optical amplifier can also transmit in the same direction as the signal light.
  • the optical amplifier may also include any two of the isolation module 7 , the gain flattening filter module 8 and the adjustable optical attenuator 9 .
  • the optical amplifier is a multi-stage optical amplifier.
  • the optical amplifier also includes N doped fiber amplification modules 4, where N is an integer greater than or equal to 1.
  • the gain medium of each doped fiber amplification module 4 can be combined with a doped fiber amplification module 4.
  • the materials of the doped optical fibers 3 are the same, and each doped optical fiber amplification module 4 can amplify the transmitted signal light.
  • the first wavelength division multiplexer 2 is located between the N doped optical fiber amplification modules 4 and the doped optical fiber 3 .
  • N doped fiber amplification modules 4 are located on the transmission path of the signal light output by the first wavelength division multiplexer 2, and the 1st to Nth
  • the doped optical fiber amplification modules 4 are arranged in sequence along the transmission direction of the signal light, see the optical amplifier shown in Figure 14.
  • the value of N in the embodiment of this application can be set according to actual needs.
  • the optical amplifier is a multi-stage optical amplifier, and the optical amplifier further includes N doped fiber amplification modules 4, where N is an integer greater than or equal to 1, and the gain medium of each doped fiber amplification module 4 can be
  • the doped optical fibers 3 are made of the same material, and each doped optical fiber amplification module 4 can amplify the transmitted signal light.
  • the first wavelength division multiplexer 2 is located between the N doped optical fiber amplification modules 4 and the doped optical fiber 3 .
  • N doped fiber amplification modules 4 are located on the transmission path of the input signal light of the first wavelength division multiplexer 2, and the 1st to Nth
  • the doped optical fiber amplification modules 4 are arranged in sequence along the transmission direction of the signal light, see the optical amplifier shown in Figure 15.
  • the value of N in the embodiment of this application can be set according to actual needs.
  • multi-stage amplification is used to make the power of the signal light reach the standard.
  • the optical amplifier also includes N doped fiber amplification modules 4, the optical amplifier also includes N isolation modules 7, and one isolation module 7 is provided between adjacent doped fiber amplification modules 4, and An isolation module 7 is also provided on the transmission path of the signal light output by the Nth doped optical fiber amplification module 4.
  • the value of N is 2.
  • the isolation module 7 can prevent the light transmitted in the opposite direction of the transmission direction of the signal light from passing through.
  • the doped optical fiber amplification module 4 can adopt a co-directional pumping method, a reverse pumping method or a bidirectional pumping method.
  • the wavelength of the pump light of the doped fiber amplification module 4 may be 980 nm.
  • the structures of the N doped optical fiber amplification modules 4 may be exactly the same or not.
  • the N doped optical fiber amplification modules 4 all adopt co-directional pumping.
  • the i-th doped optical fiber amplification module 4 adopts a co-directional pumping method
  • the j-th optical fiber amplifying module 4 adopts a reverse pumping mode.
  • the values of i and j range from 1 to N, and i is not equal to j.
  • link fiber 01 may be a G652, G653, G654, G655, G656, or G657 type fiber.
  • the embodiments of this application only illustrate several possible optical fibers, and the specific model of the link optical fiber 01 is not limited.
  • the doped fiber 3 and the link fiber 01 share the Raman pump light.
  • the link fiber is relatively long and can absorb the remaining pump light. This can improve the utilization rate of pump light.
  • the Raman pump light is first input into the doped fiber 3 and is partially absorbed. The power of the remaining pump light is reduced compared to the power of the Raman pump light. The power of the remaining pump light entering the link fiber 01 is reduced to To an acceptable range, it can solve the problem of too high power entering link fiber 01 during Raman amplification, and there is no need for pump protection measures such as OTDR or interlock switches.
  • link fiber 01 performs Raman amplification, which is equivalent to a DRA and an optical amplifier cascaded, and the DRA serves as the first stage amplifier and the optical amplifier serves as the third stage.
  • the second-level amplifier because the noise figure (NF) of DRA is relatively low, it can effectively reduce the noise figure.
  • the optical amplifier with low noise coefficient is a key component for the entire optical fiber transmission system.
  • the optical amplifier of this application and the link fiber 01 together serve as a safe, easy-to-use, low-noise optical amplifier in the future. sound amplifier.
  • an optical amplifier using two-stage amplification is taken as an example.
  • the doped optical fiber 3 of the optical amplifier is an erbium-doped optical fiber.
  • G opt the gain produced by link fiber 01
  • G EDF the gain produced by doped fiber 3
  • the performance of the optical amplifier includes gain and noise coefficient.
  • the optical amplifier can achieve a gain of 19 to 25dB. At the 24dB gain point (that is, the gain slope is 4dB), the maximum noise coefficient is around 2.5dB. Simulation and measured results are aligned.
  • the power of the remaining pump light entering the link fiber 01 is less than 24.5dBm.
  • the reason why 24.5dBm is selected as the optimal fiber input power is: the output power of the C-band high-power EDFA It is 24.5dBm, so 24.5dBm is an acceptable fiber input power value for link fiber 01.
  • the current EDFA external fiber optic connector that is, the fiber optic connector, can be used, and no safety protection measures are required.
  • the overall noise coefficient is expressed as NF1+(L*NF2-1)/G1 (linear unit).
  • NF1 is the noise coefficient of the first stage of the optical amplifier
  • NF2 is the second stage of the optical amplifier.
  • the noise figure of the stage G1 is the gain of the first stage of the optical amplifier
  • L is the insertion loss between the two stages of the optical amplifier. It can be seen from this formula that NF1 and G1 are two key parameters. When NF1 is small enough and G1 is large enough, it can ensure that the overall noise figure of the optical amplifier remains at a low level.
  • One of the benefits of this solution is to reduce the input power of the pump light on the line side. Since the gain of Raman amplification is proportional to the power of the pump light within a certain range, it is obvious that G opt ⁇ G Raman , G Raman is the gain obtained when the Raman pump light directly enters the link fiber 01 in the embodiment of the present application.
  • the optical amplifier includes a first pump module 1 , a first wavelength division multiplexer 2 and a doped optical fiber 3 .
  • the first pump module 1 outputs Raman pump light to the first wavelength division multiplexer 2
  • the first wavelength division multiplexer 2 couples the Raman pump light to the doped optical fiber 3 .
  • the doped optical fiber 3 absorbs the Raman pump light, amplifies and outputs the signal light input to the optical amplifier, and outputs the remaining pump light in the Raman pump light to the link fiber 01 connected to the optical amplifier.
  • the remaining pump light serves as the pump light in the link fiber.
  • the doped fiber 3 and the link fiber 01 can share the Raman pump light, so that the utilization rate of the pump light is relatively high.
  • the optical amplifier is the optical amplifier shown in FIG. 4 , and the signal light passes through the link fiber 01 , the doped fiber 3 and the first wavelength division multiplexer 2 in sequence.
  • the pump light passes through the first pump module 1, the first wavelength division multiplexer 2, the doped fiber 3 and the link fiber 01 in sequence.
  • the first pump module 1 outputs Raman pump light.
  • the first wavelength division multiplexer 2 couples the Raman pump light to the doped optical fiber 3 .
  • the doped optical fiber 3 absorbs the Raman pump light, amplifies the signal light input to the doped optical fiber 3 and outputs it.
  • the signal light input to the doped fiber 3 is the signal light output from the link fiber 01.
  • the doped fiber 3 also outputs the remaining pump light in the Raman pump light to the link fiber 01.
  • Link fiber 01 absorbs the remaining pump light, Raman amplifies the signal light input to link fiber 01, and the Raman amplified signal light is output to doped fiber 3, continues to be amplified, and finally undergoes the first wave division and multiplexing process.
  • first and second are used to distinguish identical or similar items with substantially the same functions and functions. It should be understood that there is no logical or logical connection between “first” and “second”. Timing dependencies do not limit the number and execution order. It should also be understood that, although the following description uses the terms first, second, etc. to describe various elements, these elements should not be limited by the terms. These terms are only used to distinguish one element from another.
  • a first pump module may be referred to as a second pump module, and similarly, a second pump module may be referred to as a first pump module, without departing from the scope of various examples. Both the first pump module and the second pump module may be pump modules, and in some cases, may be separate and distinct pump modules.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Plasma & Fusion (AREA)
  • Optics & Photonics (AREA)
  • Lasers (AREA)
  • Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)

Abstract

一种光放大器、光放大的方法和光纤通信系统，属于光纤通信技术领域。光放大器包括第一泵浦模块（1）、第一波分复用器（2）和掺杂光纤（3）。第一泵浦模块（1）用于输出拉曼泵浦光，第一波分复用器（2）用于将拉曼泵浦光耦合至掺杂光纤（3），掺杂光纤（3）用于吸收拉曼泵浦光，对输入光放大器的信号光进行放大并输出，向光放大器连接的链路光纤（01）输出拉曼泵浦光中剩余的泵浦光，剩余的泵浦光作为链路光纤（01）中的泵浦光。掺杂光纤（3）和链路光纤（01）共用拉曼泵浦光，能够提升泵浦光的利用率。

Description

光放大器、光放大的方法以及光纤通信系统
本申请要求于2022年5月10日提交中国国家知识产权局、申请号为202210507453.8、申请名称为“光放大器、光放大的方法以及光纤通信系统”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及光纤通信技术领域，特别涉及一种光放大器、光放大的方法以及光纤通信系统。
背景技术
光纤通信系统具有宽带宽、高容量和低延时等优点，被广泛用于大量数据的传输。随着传输速率的不断增大，光纤通信系统的光信噪比(optical signal to noise ratio，OSNR)会降低，而且在光纤通信系统中还通常使用光放大器补偿光纤损耗，光放大器放大信号的同时会带来一定的噪声，该噪声也会直接劣化信号的光信噪比。因此，光放大器需要向着宽带宽、低噪声和易用性强的方向发展。
目前，通常使用掺杂光纤放大器，作为光纤通信系统中的光放大器。例如，光放大器为掺铒光纤放大器(Er-doped fiber amplifier，EDFA)。掺杂光纤放大器为了使得噪声比较小，通常需要通过高反转率来实现，高反转率需要高功率的泵浦光。然而高功率的泵浦光输入掺杂光纤放大器中会存在剩余的泵浦光，剩余的泵浦光会以热量的形式耗散掉，导致光放大器的泵浦光的利用率比较低。
发明内容
本申请提供了一种光放大器、光放大的方法以及光纤通信系统，能够提升泵浦光的利用率。
第一方面，本申请提供了一种光放大器，该光放大器包括第一泵浦模块、第一波分复用器(wavelength division multiplexing，WDM)和掺杂光纤；该第一泵浦模块用于，输出拉曼泵浦光；该第一波分复用器用于，将该拉曼泵浦光耦合至该掺杂光纤；该掺杂光纤用于，吸收该拉曼泵浦光，对输入该光放大器的信号光进行放大并输出，向该光放大器连接的链路光纤输出该拉曼泵浦光中剩余的泵浦光，该剩余的泵浦光作为该链路光纤中的泵浦光。
本申请所示的方案中，光放大器使用的泵浦光为拉曼泵浦光，第一波分复用器将该拉曼泵浦光耦合至光放大器的掺杂光纤中，掺杂光纤吸收拉曼泵浦光，对输入该光放大器的信号光进行放大并输出，向该光放大器连接的链路光纤输出该拉曼泵浦光中剩余的泵浦光。链路光纤使用该剩余的泵浦光，对输入链路光纤的信号光进行拉曼放大。采用本申请的方案，掺杂光纤与链路光纤共用拉曼泵浦光，在保证掺杂光纤高反转率的前提下，链路光纤比较长，能够吸收剩余的泵浦光，从而能够提升泵浦光的利用率。而且拉曼泵浦光先输入至掺杂光纤中，被吸收一部分，剩余的泵浦光功率相比拉曼泵浦光的功率降低，进入链路光纤的剩余的泵浦光的功率降低到至可接受的范围，能够解决链路光纤对信号光拉曼放大时，进入链路光 纤的泵浦光的功率过高的问题，从而也无需泵浦保护措施。
在一种示例中，该信号光的传输方向与该掺杂光纤中传输的该拉曼泵浦光的传输方向相反；该信号光的传输方向与该链路光纤中该剩余的泵浦光的传输方向相反。
本申请所示的方案中，信号光的传输方向与泵浦光的传输方向相反，能够实现链路光纤和光放大器的反向泵浦，使得链路光纤的非线性代价比较小。
在一种示例中，该信号光的传输方向与该掺杂光纤中传输的该拉曼泵浦光的传输方向相同；该信号光的传输方向与该链路光纤中该剩余的泵浦光的传输方向相同。
本申请所示的方案中，信号光的传输方向与泵浦光的传输方向相同，能够实现链路光纤和光放大器的同向泵浦。
在一种示例中，该掺杂光纤与该链路光纤熔接，或者，通过光纤连接器连接。这样，提供了掺杂光纤与链路光纤的多种连接方式。
在一种示例中，该第一泵浦模块包括多个泵浦单元和合束单元；该多个泵浦单元用于，输出多个不同波长的泵浦光；该合束单元用于，将该多个不同波长的泵浦光合并为一束该拉曼泵浦光。
本申请所示的方案中，拉曼泵浦光可以由多个不同波长的泵浦光合束获得。
在一种示例中，该拉曼泵浦光的波长范围为1400nm～1520nm。
在一种示例中，该光放大器还包括N个掺杂光纤放大模块，N为大于或等于1的整数；该N个掺杂光纤放大模块中第1个至第N个掺杂光纤放大模块沿着该信号光的传输方向依次排列；该第一波分复用器位于该N个掺杂光纤放大模块与该掺杂光纤之间。
本申请所示的方案中，光放大器可以是多级放大器，能够使得信号光经过光放大器后的增益满足要求。
在一种示例中，该光放大器还包括第二泵浦模块和第二波分复用器；该第二泵浦模块用于，输出第一泵浦光；该第二波分复用器用于，将该第一泵浦光耦合至该掺杂光纤；该掺杂光纤用于，吸收该拉曼泵浦光和该第一泵浦光，对该信号光进行放大并输出，该第一泵浦光与该拉曼泵浦光的传输方向相反。
本申请所示的方案中，光放大器采用双向泵浦方式，能够使得信号光经过光放大器后的增益满足要求。
在一种示例中，该光放大器还包括隔离模块；该隔离模块用于，阻止该信号光传输方向的逆方向上传输的光通过。
这样，通过隔离模块阻止信号光传输方向的逆方向上传输的光通过，能够使得信号光的逆方向传输的光不会影响光放大器。
第二方面，本申请提供了一种光放大的方法，该方法应用于第一方面或第一方面任一方面所述的光放大器，该光放大器包括第一泵浦模块、第一波分复用器和掺杂光纤，该方法包括：该第一泵浦模块向该第一波分复用器输出拉曼泵浦光；该第一波分复用器将该拉曼泵浦光耦合至该掺杂光纤；该掺杂光纤吸收该拉曼泵浦光，对输入该光放大器的信号光进行放大并输出，向该光放大器连接的链路光纤输出该拉曼泵浦光中剩余的泵浦光，该剩余的泵浦光作为该链路光纤中的泵浦光。
本申请所示的方案中，掺杂光纤与链路光纤共用拉曼泵浦光，在保证掺杂光纤高反转率的前提下，链路光纤比较长，能够吸收剩余的泵浦光，从而能够提升泵浦光的利用率。而且拉曼泵浦光先输入至掺杂光纤中，被吸收一部分，剩余的泵浦光功率相比拉曼泵浦光的功率 降低，进入链路光纤的剩余泵浦光的功率降低到至可接受的范围，能够解决链路光纤对信号光拉曼放大时，进入链路光纤的泵浦光的功率过高的问题，从而也无需泵浦保护措施。
在一种示例中，该信号光的传输方向与该掺杂光纤中传输的该拉曼泵浦光的传输方向相反；该信号光的传输方向与该链路光纤中该剩余的泵浦光的传输方向相反。
本申请所示的方案中，信号光的传输方向与泵浦光的传输方向相反，能够实现链路光纤和光放大器的反向泵浦，使得链路光纤的非线性代价比较小。
第三方面，本申请提供了一种光纤通信系统，光纤通信系统包括第一网元、第二网元和至少一个第一方面或第一方面任一方面所述的光放大器；该光放大器位于该第一网元与该第二网元之间。
附图说明
图1是传统的光放大器的示意图；
图2是另一种传统的光放大器的示意图；
图3是本申请一个示例性的实施例提供的光纤通信系统的结构示意图；
图4是本申请一个示例性的实施例提供的光放大器的结构示意图；
图5是本申请一个示例性的实施例提供的光放大器的结构示意图；
图6是本申请一个示例性的实施例提供的光放大器的结构示意图；
图7是本申请一个示例性的实施例提供的光放大器的结构示意图；
图8是本申请一个示例性的实施例提供的光放大器的结构示意图；
图9是本申请一个示例性的实施例提供的光放大器的结构示意图；
图10是本申请一个示例性的实施例提供的光放大器的结构示意图；
图11是本申请一个示例性的实施例提供的光放大器的结构示意图；
图12是本申请一个示例性的实施例提供的光放大器的结构示意图；
图13是本申请一个示例性的实施例提供的光放大器的结构示意图；
图14是本申请一个示例性的实施例提供的光放大器的结构示意图；
图15是本申请一个示例性的实施例提供的光放大器的结构示意图；
图16是本申请一个示例性的实施例提供的光放大器的结构示意图；
图17是本申请一个示例性的实施例提供的光放大器的结构示意图；
图18是本申请一个示例性的实施例提供的光放大器的性能仿真和实测结果示意图。
图示说明
1、第一泵浦模块；2、第一波分复用器；3、掺杂光纤；01、链路光纤；
4、掺杂光纤放大模块；5、第二泵浦模块；6、第二波分复用器；
7、隔离模块；8、增益平坦滤波模块；9、可调光衰减器(variable optical attenuator，VOA)；
11、泵浦单元；12、合束单元。
具体实施方式
为使本申请的目的、技术方案和优点更加清楚，下面将结合附图对本申请实施方式作进一步地详细描述。
下面对本申请实施例涉及的一些术语概念做解释说明。
1、拉曼效应，指光通过光纤介质时由于入射光与分子运动相互作用而引起的频率发生变化的散射。拉曼效应也称为拉曼散射。
2、分布式拉曼光放大器(disturbed Raman amplifier，DRA)，是长距离传输中，将链路光纤作为拉曼增益介质的光放大器，链路光纤也可以称为传输光纤。在DRA的泵浦光由不同波长的光合束得到时，可以实现宽谱信号光的放大。
3、掺铒光纤放大器(Er-doped fiber amplifier，EDFA)，在信号光通过的纤芯中掺入铒离子的光纤放大器。
下面描述本申请的背景。
光纤通信系统具有带宽大、容量高和延时低等优点，被广泛应用于海量数据的传输中。随着传输速率的不断增大，光纤通信系统的OSNR会降低，而且在光纤通信系统中还会通常使用光放大器补偿光纤损耗，光放大器放大信号的同时会带来一定的噪声，该噪声会直接劣化信号的OSNR。因此，光放大器需要向着宽带宽、低噪声和易用性强的方向发展。
目前，通常使用掺杂光纤放大器，作为光纤通信系统中的光放大器。例如，参见图1，光放大器为EDFA，且示出了两个级联的EDFA，即EDFA1和EDFA2。掺杂光纤放大器为了使得噪声比较小，通常需要通过高反转率来实现，高反转率需要高功率的泵浦光。然而高功率的泵浦光输入掺杂光纤放大器中会存在剩余的泵浦光，剩余的泵浦光会以热量的形式耗散掉，导致光放大器的泵浦光的利用率比较低。
在另一种光放大器中，将DRA与EDFA相互配合，作为线路侧的光放大器，该光放大器的名称为拉曼放大单元(Raman amplifier unit，RAU)，结构参见图2。在图2中，DRA级联EDFA，拉曼泵浦光通过波分复用器输入到链路光纤中，实现对信号光的放大，在图2所示的光放大器中，拉曼泵浦光的功率相对较高，所以DRA在应用上有烧纤和人眼安全等安全风险，因此，需要在安全方面采取一系列措施。例如，在物理层面的互锁开关实现光纤关闭拉曼泵浦源的安全保护。在光放大器内部集成光时域反射仪(optical time-domain reflectometer，OTDR)来检测断纤或者光纤端面脏污以实现快速关闭拉曼泵浦源，这些安全措施，虽然能起到泵浦安全保护的作用，但是没有从根本上降低泵浦光进入线路光纤中的功率，依然会使得链路光纤断开等风险。
此处拉曼泵浦光功率高会烧纤的原因为：光放大器与链路光纤连接处通常会出现脏污，特别是一些有机物吸附在连接处，导致高功率的拉曼泵浦光在连接处产生热量，使得光纤烧坏。
基于此，本申请提供了一种光放大器，拉曼泵浦光先输入掺杂光纤中，被掺杂光纤吸收一部分后，剩余的泵浦光输入至链路光纤中，作为链路光纤中的泵浦光。这样，实现掺杂光纤和链路光纤共用拉曼泵浦光，且链路光纤比较长，能够充分吸收剩余的泵浦光，使得泵浦光的利用率比较高。而且由于拉曼泵浦光先被掺杂光纤吸收一部分，使得进入链路光纤的泵浦光的功率会被降低，省去拉曼放大时相关的泵浦安全保护。
下面描述本申请实施例中光放大器的应用场景。
本申请实施例中的光放大器可以应用于光纤通信系统。参见图3，光纤通信系统包括第一网元101、第二网元102和至少一个光放大器。第一网元101可以是光纤通信系统中的发送设备，第二网元102可以是光纤通信系统中的接收设备。或者，第一网元101可以是光纤通信系统中发送设备和接收设备之间的任意两个设备。
在一种示例中，光放大器可以作为光纤通信系统的中继放大器，中继放大器位于第一网元101与第二网元102的中间。
在另一种示例中，光放大器可以作为光纤通信系统的前置放大器，前置放大器位于第二网元102之前，对进入第二网元102的信号光进行放大。
在另一种示例中，光放大器可以作为光纤通信系统的后置放大器，后置放大器位于第一网元101之后，对第一网元101输出的信号光进行放大。
下面描述本申请实施例中光放大器的结构。
光放大器包括第一泵浦模块1、第一波分复用器2和掺杂光纤3。第一泵浦模块1是提供拉曼泵浦光的光源。第一泵浦模块1与第一波分复用器2连接，第一波分复用器2与掺杂光纤3连接，掺杂光纤3与链路光纤01连接。链路光纤01是线路侧的光纤。
第一泵浦模块1输出拉曼泵浦光。第一波分复用器2将拉曼泵浦光耦合至掺杂光纤3。掺杂光纤3吸收拉曼泵浦光，对输入光放大器的信号光进行放大并输出。拉曼泵浦光经过掺杂光纤3后会存在剩余的泵浦光。掺杂光纤3还向链路光纤01输出拉曼泵浦光中剩余的泵浦光。链路光纤01吸收该剩余的泵浦光，拉曼放大信号光。
这样，掺杂光纤3和链路光纤01共用拉曼泵浦光，能够使得泵浦光的利用率比较高。
需要说明的是，链路光纤01远比掺杂光纤3的长度长，能够充分吸收剩余的泵浦光。
在一种示例中，光放大器采用反向泵浦方式，并且链路光纤01也采用反向泵浦方式。反向泵浦方式指信号光与泵浦光的传输方向相反的泵浦方式。图4示例性的提供了光放大器的结构示意图。参见图4，光放大器包括第一泵浦模块1、第一波分复用器2和掺杂光纤3。第一泵浦模块1是提供拉曼泵浦光的光源。第一波分复用器2是一个三端口器件，第一泵浦模块1与第一波分复用器2的第一个端口连接，第一波分复用器2的第二个端口与掺杂光纤3连接，第一波分复用器2的第三个端口可以作为光放大器的输出端口。掺杂光纤3与链路光纤01连接，且链路光纤01连接在掺杂光纤3的信号光输入端。
在图4所示的光放大器中，信号光依次通过链路光纤01、掺杂光纤3和第一波分复用器2。拉曼泵浦光从第一泵浦模块1输出后，依次通过第一波分复用器2、掺杂光纤3和链路光纤01。具体的，第一泵浦模块1输出拉曼泵浦光。第一波分复用器2将拉曼泵浦光耦合至掺杂光纤3。掺杂光纤3吸收拉曼泵浦光，对输入掺杂光纤3的信号光进行放大并输出。输入掺杂光纤3的信号光为从链路光纤01输出的信号光。掺杂光纤3还向链路光纤01输出拉曼泵浦光中剩余的泵浦光。链路光纤01比较长，能够充分吸收该剩余的泵浦光，拉曼放大输入链路光纤01的信号光，拉曼放大后的信号光输出至掺杂光纤3中，继续被放大，最后经过第一波分复用器2进行输出。
采用图4所示的光放大器，由于拉曼放大时，采用了反向泵浦方式，所以可以降低链路光纤01中的非线性代价。
在另一种示例中，光放大器采用同向泵浦方式，并且链路光纤01也采用同向泵浦方式。同向泵浦方式指信号光与泵浦光的传输方向相同的泵浦方式。图5示例性的提供了光放大器的结构示意图。参见图5，光放大器包括第一泵浦模块1、第一波分复用器2和掺杂光纤3。第一波分复用器2是一个三端口器件，第一泵浦模块1与第一波分复用器2的第一个端口连接，第一波分复用器2的第二个端口与掺杂光纤3连接，第一波分复用器2的第三个端口可以作为光放大器的输入端口。掺杂光纤3与链路光纤01连接，且链路光纤01连接在掺杂光纤3的信号光输出端。
在图5所示的光放大器中，信号光依次通过第一波分复用器2、掺杂光纤3和链路光纤01。拉曼泵浦光从第一泵浦模块1输出后，依次通过第一波分复用器2、掺杂光纤3和链路光纤01。具体的，第一泵浦模块1输出拉曼泵浦光。第一波分复用器2将拉曼泵浦光耦合至 掺杂光纤3，并且将接收到的信号光，输出至掺杂光纤3。掺杂光纤3吸收拉曼泵浦光，对输入掺杂光纤3的信号光进行放大，向链路光纤01输出放大处理后的信号光。掺杂光纤3还向链路光纤01输出拉曼泵浦光中剩余的泵浦光。链路光纤01比较长，能够充分吸收该剩余的泵浦光，拉曼放大输入链路光纤01的信号光，输出拉曼放大后的信号光。
在一种示例中，光放大器中传输的信号光为波分复用信号光。波分复用信号光包括多个波段的信号光。例如，波分复用信号光的波长范围可以是1520nm～1630nm。
在一种示例中，光放大器可以是EDFA，掺杂光纤3中至少掺杂有铒离子。
在一种示例中，信号光可以是常规(conventional，C)波段的光、长(long，L)波段的光或者C+L波段的光，掺杂光纤3可以是单模掺铒光纤、大模场掺铒光纤或者双包层掺铒光纤等。
在一种示例中，掺杂光纤3与链路光纤01直接连接，掺杂光纤3与链路光纤01通过熔接的方式连接，或者，掺杂光纤3与链路光纤01通过光纤连接器连接。
其中，光纤连接器可以是任意一种用于连接光纤的连接器，本申请实施例不进行限定。通过熔接的方式连接，相比通过光纤连接器连接能够降低损耗。
在一种示例中，第一泵浦模块1提供的拉曼泵浦光包括不同波长的泵浦光。具体的，参见图6所示的光放大器，第一泵浦模块1包括多个泵浦单元11和合束单元12，多个泵浦单元11分别与合束单元12连接，合束单元12与第一波分复用器2连接。
多个泵浦单元11能够输出多个不同波长的泵浦光，每个泵浦单元11输出一个波长的泵浦光，多个泵浦单元11输出的泵浦光的功率可以相同，也可以不相同。合束单元12将多个不同波长的泵浦光合并为一束拉曼泵浦光。合束单元12将拉曼泵浦光输出至第一波分复用器2。图6是以反向泵浦方式为例进行描述，同向泵浦方式与之类似，此处不再赘述。
可选的，在多个泵浦单元11为两个泵浦单元11的情况下，两个泵浦单元11输出的两束泵浦光的偏振态可以是正交的，合束单元12可以是偏振合束器。
可选的，泵浦单元11可以是半导体激光器、光纤激光器或者固体激光器等。
可选的，拉曼泵浦光的功率可以根据实际需要设置。例如，拉曼泵浦光的功率可以设置为使得剩余的泵浦光的功率不会烧纤。
在一种示例中，拉曼泵浦光的波长范围为1400nm～1520nm。例如，信号光为C波段的光，C波段的拉曼泵浦光由两个1400nm～1499nm范围的泵浦光通过合束单元12合束获得。
可选的，两个泵浦光的波长为1427nm和1465nm。
在一种示例中，光放大器采用的是双向泵浦方式，且拉曼泵浦光与信号光的传输方向相反。具体的，光纤放大器包括第一泵浦模块1、第一波分复用器2、掺杂光纤3、第二泵浦模块5和第二波分复用器6。第二泵浦模块5能够输出第一泵浦光，第一泵浦光可以是单波长的泵浦光。第二泵浦模块5与第二波分复用器6连接。第二波分复用器6与掺杂光纤3连接，参见图7所示的光放大器。
在图7所示的光放大器中，第二波分复用器6接收输入光放大器中的信号光，将信号光输出至掺杂光纤3中。第二波分复用器6还将第一泵浦光耦合至掺杂光纤3中，第一泵浦光在掺杂光纤3中的传输方向与信号光在掺杂光纤3中的传输方向相同。
第一波分复用器2将拉曼泵浦光耦合至掺杂光纤3中，拉曼泵浦光在掺杂光纤3中的传输方向与信号光在掺杂光纤3中的传输方向相反。
掺杂光纤3吸收拉曼泵浦光和第一泵浦光，对输入掺杂光纤3中的信号光进行放大，并将放大处理后的信号光输出至第一波分复用器2。掺杂光纤3还向链路光纤01输出拉曼泵浦 光中剩余的泵浦光。链路光纤01比较长，能够充分吸收该剩余的泵浦光，拉曼放大输入链路光纤01的信号光，输出拉曼放大后的信号光，拉曼放大后的信号光经过第二波分复用器6输出至掺杂光纤3，掺杂光纤3继续对该拉曼放大后的信号光进行放大，将放大处理后的信号光输出至第一波分复用器2。第一波分复用器2将该放大处理后的信号光透传输出。
在另一种示例中，光放大器也采用的是双向泵浦方式，且拉曼泵浦光与信号光的传输方向相同。具体的，光纤放大器包括第一泵浦模块1、第一波分复用器2、掺杂光纤3、第二泵浦模块5和第二波分复用器6。第二泵浦模块5能够输出第一泵浦光，第一泵浦光可以是单波长的泵浦光。第二泵浦模块5与第二波分复用器6连接。第二波分复用器6与掺杂光纤3连接，参见图8所示的光放大器。
在图8所示的光放大器中，第一波分复用器2接收输入光放大器的信号光，将信号光输出至掺杂光纤3中。第一波分复用器2还将拉曼泵浦光耦合至掺杂光纤3中，拉曼泵浦光在掺杂光纤3中的传输方向与信号光在掺杂光纤3中的传输方向相同。
第二波分复用器6将第一泵浦光耦合至掺杂光纤3中，第一泵浦光在掺杂光纤3中的传输方向与信号光在掺杂光纤3中的传输方向相反。
掺杂光纤3吸收拉曼泵浦光和第一泵浦光，对输入掺杂光纤3中的信号光进行放大，并将放大处理后的信号光输出至第二波分复用器6。掺杂光纤3还向第二波分复用器6输出拉曼泵浦光中剩余的泵浦光。第二波分复用器6将该放大处理后的信号光和剩余的泵浦光透传输出至链路光纤01。链路光纤01比较长，能够充分吸收该剩余的泵浦光，拉曼放大输入链路光纤01的信号光，输出拉曼放大后的信号光。
在一种示例中，为了使得光放大器输出的光不会返回光放大器，光放大器中还包括隔离模块7。在拉曼泵浦光与信号光的传输方向相反的情况下，隔离模块7位于第一波分复用器2输出信号光的传输路径上，参见图9所示的光放大器。在拉曼泵浦光与信号光的传输方向相同的情况下，隔离模块7位于掺杂光纤3输出信号光的传输路径上，参见图10所示的光放大器。
其中，隔离模块7可以阻止信号光传输方向的逆方向传输的光通过。例如，隔离模块7可以是隔离器(isolator，ISO)。
在一种示例中，为了使得光放大器输出的信号光的增益谱平坦，光放大器还包括增益平坦滤波模块8。在拉曼泵浦光与信号光的传输方向相反的情况下，增益平坦滤波模块8位于第一波分复用器2输出信号光的传输路径上，参见图11所示的光放大器。在拉曼泵浦光与信号光的传输方向相同的情况下，增益平坦滤波模块8位于掺杂光纤3输出信号光的传输路径上，参见图12所示的光放大器。
其中，增益平坦滤波模块8可以用于对掺杂光纤3输出的信号光进行平坦滤波。例如，增益平坦滤波模块8可以是增益平坦滤波器(gain flattening filters，GFF)。
在一种示例中，为了使得光放大器输出的信号光的功率可调，光放大器还包括可调光衰减器9。在拉曼泵浦光与信号光的传输方向相反的情况下，可调光衰减器9位于第一波分复用器2输出信号光的传输路径上。在拉曼泵浦光与信号光的传输方向相同的情况下，可调光衰减器9位于掺杂光纤3输出信号光的传输路径上。
其中，可调光衰减器9可以用于对掺杂光纤3输出的信号光进行衰减。
在一种示例中，光放大器包括隔离模块7、增益平坦滤波模块8和可调光衰减器9的情况下，掺铒光纤3输出的信号光依次通过隔离模块7、增益平坦滤波模块8和可调光衰减器9，参见图13所示的光放大器。图13所示的光放大器是以拉曼泵浦光与信号光的传输方向相反 为例，光放大器中拉曼泵浦光还可以与信号光的传输方向相同。
需要说明的是，光放大器也可以包括隔离模块7、增益平坦滤波模块8和可调光衰减器9中的任意两个。
在一种示例中，光放大器是多级光放大器，光放大器还包括N个掺杂光纤放大模块4，N为大于或等于1的整数，每个掺杂光纤放大模块4的增益介质可以与掺杂光纤3的材料相同，每个掺杂光纤放大模块4均能对传输的信号光进行放大处理。第一波分复用器2位于N个掺杂光纤放大模块4与掺杂光纤3之间。在拉曼泵浦光与信号光的传输方向相反的情况下，N个掺杂光纤放大模块4位于第一波分复用器2输出信号光的传输路径上，且第1个至第N个掺杂光纤放大模块4沿着信号光的传输方向依次排列，参见图14所示的光放大器。本申请实施例中N的取值可以根据实际需要设置。
在另一种示例中，光放大器是多级光放大器，光放大器还包括N个掺杂光纤放大模块4，N为大于或等于1的整数，每个掺杂光纤放大模块4的增益介质可以与掺杂光纤3的材料相同，每个掺杂光纤放大模块4均能对传输的信号光进行放大处理。第一波分复用器2位于该N个掺杂光纤放大模块4与该掺杂光纤3之间。在拉曼泵浦光与信号光的传输方向相同的情况下，N个掺杂光纤放大模块4位于第一波分复用器2输入信号光的传输路径上，且第1个至第N个掺杂光纤放大模块4沿着信号光的传输方向依次排列，参见图15所示的光放大器。本申请实施例中N的取值可以根据实际需要设置。
在图14和图15所示的光放大器中，采用多级放大，能够使得信号光的功率达标。
可选的，在光放大器还包括N个掺杂光纤放大模块4的情况下，光放大器还包括N个隔离模块7，相邻的掺杂光纤放大模块4之间设置有一个隔离模块7，且第N个掺杂光纤放大模块4输出信号光的传输路径上还设置有一个隔离模块7，参见图16所示的光放大器，图16所示的光放大器中，N的取值为2。隔离模块7可以阻止信号光的传输方向的逆方向传输的光通过。
可选的，掺杂光纤放大模块4可以采用同向泵浦方式、反向泵浦方式或者双向泵浦方式。
可选的，在信号光包括C波段的光时，掺杂光纤放大模块4的泵浦光的波长可以为980nm。
可选的，N个掺杂光纤放大模块4的结构可以完全相同，或者不完全相同。例如，N个掺杂光纤放大模块4均采用同向泵浦方式。再例如，第i个掺杂光纤放大模块4采用同向泵浦方式，第j个光纤放大模块4采用反向泵浦方式，i和j取值属于1至N，且i不等于j。
在一种示例中，链路光纤01可以是G652、G653、G654、G655、G656或G657型号的光纤。本申请实施例仅是示例性的给出几种可能的光纤，对链路光纤01的具体型号不进行限定。
本申请实施例中，掺杂光纤3与链路光纤01共用拉曼泵浦光，在保证掺杂光纤3高反转率的前提下，链路光纤比较长，能够吸收剩余的泵浦光，进而能够提升泵浦光的利用率。而且拉曼泵浦光先输入至掺杂光纤3中，被吸收一部分，剩余的泵浦光功率相比拉曼泵浦光的功率降低，进入链路光纤01的剩余泵浦光的功率降低到至可接受的范围，能够解决拉曼放大时，进入链路光纤01的功率过高的问题，也无需OTDR或互锁开关等泵浦保护措施。
而且在拉曼泵浦光与信号光的传输方向相反的情况下，链路光纤01进行拉曼放大，相当于一个DRA和一个光放大器级联，且DRA作为第一级放大器，光放大器作为第二级放大器，由于DRA的噪声系数(noise figure，NF)比较低，所以能够有效较低噪声系数。
而且在未来大容量光纤传输系统中，由于OSNR受限，低噪声系数的光放大器对于整个光纤传输系统是关键器件，本申请的光放大器和链路光纤01共同作为未来安全易用，且低噪 声的放大器。
本申请实施例中，为了便于说明和实验验证，以采用两级放大的光放大器为例，参见图17所示的光放大器，光放大器为的掺杂光纤3采用掺铒光纤。将链路光纤01产生的增益记为Gopt，将掺杂光纤3产生的增益记为GEDF。参见图18所示的光放大器的性能仿真和实测结果。在图18中，光放大器的性能包括增益和噪声系数，光放大器可以实现19～25dB增益可达，在24dB增益点位置处(即增益倾斜度为4dB)，最大的噪声系数在2.5dB左右，仿真和实测结果对齐。并且从实测结果和仿真结果可以得到，剩余的泵浦光进入链路光纤01的功率小于24.5dBm，其中，选择24.5dBm为最佳入纤功率的原因是：C波段的高功率EDFA的输出功率是24.5dBm，所以24.5dBm对于链路光纤01来说是一个可接受的入纤功率值，可以沿用目前EDFA的外部光纤接头，即光纤连接器，同样地不需要安全保护措施。
对于图17所示的两级光放大器，整体的噪声系数表示为NF1+(L*NF2-1)/G1(线性单位)NF1是光放大器的第一级的噪声系数，NF2是光放大器的第二级的噪声系数，G1是光放大器的第一级的增益，L为光放大器两级之间的插损。从该式子可以看出，NF1和G1是两个关键的参数，当NF1足够小且G1足够大时，可以保证光放大器整体的噪声系数保持在一个低水平。
由于Gopt和GEDF是由同一个泵浦源(即第一泵浦模块1)产生的增益，所以可以把这两块看做整体，作为两级光放的第一级，即G1＝Gopt+GEDF。该方案的收益之一是降低了线路侧的泵浦光的入纤功率，由于拉曼放大的增益一定范围内是正比于泵浦光的功率，那么显然Gopt<G拉曼，G拉曼为本申请实施例中拉曼泵浦光直接进入链路光纤01时获得的增益，若没有掺铒光纤的增益GEDF，那么对于整个两级光放大器的增益和噪声系数肯定是会劣化的，所以加入掺铒光纤刚好可以提高第一级的增益G1。而且从仿真和实测结果看G1＝Gopt+GEDF>G拉曼，参考两级光放的噪声系数式子，加入掺铒光纤提高了G1，仍然可以使整体的噪声系数保持在低水平。
本申请实施例还提供了一种光放大的方法，该方法应用于前文中描述的光放大器。如前文描述可知，光放大器包括第一泵浦模块1、第一波分复用器2和掺杂光纤3。第一泵浦模块1向第一波分复用器2输出拉曼泵浦光，第一波分复用器2将拉曼泵浦光耦合至掺杂光纤3。掺杂光纤3吸收该拉曼泵浦光，对输入该光放大器的信号光进行放大并输出，向该光放大器连接的链路光纤01输出该拉曼泵浦光中剩余的泵浦光，该剩余的泵浦光作为该链路光纤中的泵浦光。这样，可以使得掺杂光纤3和链路光纤01共用拉曼泵浦光，使得泵浦光的利用率比较高。
在一种示例中，光放大器为图4所示的光放大器，信号光依次通过链路光纤01、掺杂光纤3和第一波分复用器2。泵浦光依次通过第一泵浦模块1、第一波分复用器2、掺杂光纤3和链路光纤01。具体的，第一泵浦模块1输出拉曼泵浦光。第一波分复用器2将拉曼泵浦光耦合至掺杂光纤3。掺杂光纤3吸收拉曼泵浦光，对输入掺杂光纤3的信号光进行放大并输出。输入掺杂光纤3的信号光为从链路光纤01输出的信号光。掺杂光纤3还向链路光纤01输出拉曼泵浦光中剩余的泵浦光。链路光纤01吸收该剩余的泵浦光，拉曼放大输入链路光纤01的信号光，拉曼放大后的信号光输出至掺杂光纤3中，继续被放大，最后经过第一波分复用器2进行输出。
这样，由于拉曼放大时，采用了反向泵浦方式，所以可以降低链路光纤01中的非线性代价。
光放大的方法的具体描述参见前文中的描述，此处不再赘述。
本申请中术语“第一”和“第二”等字样用于对作用和功能基本相同的相同项或相似项进行区分，应理解，“第一”和“第二”之间不具有逻辑或时序上的依赖关系，也不对数量和执行顺序进行限定。还应理解，尽管以下描述使用术语第一、第二等来描述各种元素，但这些元素不应受术语的限制。这些术语只是用于将一元素与另一元素区别分开。例如，在不脱离各种示例的范围的情况下，第一泵浦模块可以被称为第二泵浦模块，并且类似地，第二泵浦模块可以被称为第一泵浦模块。第一泵浦模块和第二泵浦模块都可以是泵浦模块，并且在某些情况下，可以是单独且不同的泵浦模块。
本申请中术语“至少一个”的含义是指一个或多个，本申请中术语“多个”的含义是指两个或两个以上。
以上描述，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到各种等效的修改或替换，这些修改或替换都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以权利要求的保护范围为准。

Claims (12)

  1. 一种光放大器，其特征在于，所述光放大器包括第一泵浦模块(1)、第一波分复用器(2)和掺杂光纤(3)；
    所述第一泵浦模块(1)用于，输出拉曼泵浦光；
    所述第一波分复用器(2)用于，将所述拉曼泵浦光耦合至所述掺杂光纤(3)；
    所述掺杂光纤(3)用于，吸收所述拉曼泵浦光，对输入所述光放大器的信号光进行放大并输出，向所述光放大器连接的链路光纤(01)输出所述拉曼泵浦光中剩余的泵浦光，所述剩余的泵浦光作为所述链路光纤(01)中的泵浦光。
  2. 根据权利要求1所述的光放大器，其特征在于，所述信号光的传输方向与所述掺杂光纤(3)中传输的所述拉曼泵浦光的传输方向相反；
    所述信号光的传输方向与所述链路光纤(01)中所述剩余的泵浦光的传输方向相反。
  3. 根据权利要求1所述的光放大器，其特征在于，所述信号光的传输方向与所述掺杂光纤(3)中传输的所述拉曼泵浦光的传输方向相同；
    所述信号光的传输方向与所述链路光纤(01)中所述剩余的泵浦光的传输方向相同。
  4. 根据权利要求1至3任一项所述的光放大器，其特征在于，所述掺杂光纤(3)与所述链路光纤(01)熔接，或者，通过光纤连接器连接。
  5. 根据权利要求1至4任一项所述的光放大器，其特征在于，所述第一泵浦模块(1)包括多个泵浦单元(11)和合束单元(12)；
    所述多个泵浦单元(11)用于，输出多个不同波长的泵浦光；
    所述合束单元(12)用于，将所述多个不同波长的泵浦光合并为一束所述拉曼泵浦光。
  6. 根据权利要求1至5任一项所述的光放大器，其特征在于，所述拉曼泵浦光的波长范围为1400nm～1520nm。
  7. 根据权利要求1至6任一项所述的光放大器，其特征在于，所述光放大器还包括N个掺杂光纤放大模块(4)，N为大于或等于1的整数；
    所述N个掺杂光纤放大模块(4)中第1个至第N个掺杂光纤放大模块(4)沿着所述信号光的传输方向依次排列；
    所述第一波分复用器(2)位于所述N个掺杂光纤放大模块(4)与所述掺杂光纤(3)之间。
  8. 根据权利要求1至3任一项所述的光放大器，其特征在于，所述光放大器还包括第二泵浦模块(5)和第二波分复用器(6)；
    所述第二泵浦模块(5)用于，输出第一泵浦光；
    所述第二波分复用器(6)用于，将所述第一泵浦光耦合至所述掺杂光纤(3)；
    所述掺杂光纤(3)用于，吸收所述拉曼泵浦光和所述第一泵浦光，对所述信号光进行放大并输出，所述第一泵浦光与所述拉曼泵浦光的传输方向相反。
  9. 根据权利要求1至8任一项所述的光放大器，其特征在于，所述光放大器(1)还包括隔离模块(7)；
    所述隔离模块(7)用于，阻止所述信号光传输方向的逆方向上传输的光通过。
  10. 一种光放大的方法，其特征在于，所述方法应用于如权利要求1至9任一项所述的光 放大器，所述光放大器包括第一泵浦模块(1)、第一波分复用器(2)和掺杂光纤(3)，所述方法包括：
    所述第一泵浦模块(1)向所述第一波分复用器(2)输出拉曼泵浦光；
    所述第一波分复用器(2)将所述拉曼泵浦光耦合至所述掺杂光纤(3)；
    所述掺杂光纤(3)吸收所述拉曼泵浦光，对输入所述光放大器的信号光进行放大并输出，向所述光放大器连接的链路光纤(01)输出所述拉曼泵浦光中剩余的泵浦光，所述剩余的泵浦光作为所述链路光纤中的泵浦光。
  11. 根据权利要求10所述的方法，其特征在于，所述信号光的传输方向与所述掺杂光纤(3)中传输的所述拉曼泵浦光的传输方向相反；
    所述信号光的传输方向与所述链路光纤(01)中所述剩余的泵浦光的传输方向相反。
  12. 一种光纤通信系统，其特征在于，所述光纤通信系统包括第一网元、第二网元和至少一个如权利要求1至9任一项所述的光放大器；
    所述光放大器位于所述第一网元与所述第二网元之间。
PCT/CN2023/092966 2022-05-10 2023-05-09 光放大器、光放大的方法以及光纤通信系统 WO2023217131A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202210507453.8 2022-05-10
CN202210507453.8A CN117080847A (zh) 2022-05-10 2022-05-10 光放大器、光放大的方法以及光纤通信系统

Publications (1)

Publication Number Publication Date
WO2023217131A1 true WO2023217131A1 (zh) 2023-11-16

Family

ID=88706678

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2023/092966 WO2023217131A1 (zh) 2022-05-10 2023-05-09 光放大器、光放大的方法以及光纤通信系统

Country Status (2)

Country Link
CN (1) CN117080847A (zh)
WO (1) WO2023217131A1 (zh)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001065646A2 (en) * 2000-02-29 2001-09-07 Jds Uniphase Corporation Multiple stage optical fiber amplifier
US20020008901A1 (en) * 1995-03-20 2002-01-24 Susumu Kinoshita Optical fiber amplifier and dispersion compensating fiber module for optical fiber amplifier
US20020149839A1 (en) * 2001-02-14 2002-10-17 Alcatel Optical fiber amplifier
CN1925372A (zh) * 2006-07-11 2007-03-07 无锡市中兴光电子技术有限公司 一种远程传感系统
KR100757074B1 (ko) * 2006-04-06 2007-09-10 한국과학기술연구원 잉여 라만 펌핑광을 재활용하여 펌핑된 가입자용 ａｓｅ광원을 사용하는 라만 증폭 기반의 양방향 파장분할다중수동광네트워크
CN103022866A (zh) * 2012-12-17 2013-04-03 北京化工大学 Mopa型随机光纤激光器
CN107171169A (zh) * 2017-07-03 2017-09-15 无锡市德科立光电子技术有限公司 组合拉曼泵浦源及拉曼放大器
CN209844966U (zh) * 2019-07-12 2019-12-24 无锡瀚诺光电科技有限公司 混合放大器
CN113824502A (zh) * 2021-11-19 2021-12-21 北京邮电大学 一种混合光纤放大器的参数调节方法及混合光纤放大器

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020008901A1 (en) * 1995-03-20 2002-01-24 Susumu Kinoshita Optical fiber amplifier and dispersion compensating fiber module for optical fiber amplifier
WO2001065646A2 (en) * 2000-02-29 2001-09-07 Jds Uniphase Corporation Multiple stage optical fiber amplifier
US20020149839A1 (en) * 2001-02-14 2002-10-17 Alcatel Optical fiber amplifier
KR100757074B1 (ko) * 2006-04-06 2007-09-10 한국과학기술연구원 잉여 라만 펌핑광을 재활용하여 펌핑된 가입자용 ａｓｅ광원을 사용하는 라만 증폭 기반의 양방향 파장분할다중수동광네트워크
CN1925372A (zh) * 2006-07-11 2007-03-07 无锡市中兴光电子技术有限公司 一种远程传感系统
CN103022866A (zh) * 2012-12-17 2013-04-03 北京化工大学 Mopa型随机光纤激光器
CN107171169A (zh) * 2017-07-03 2017-09-15 无锡市德科立光电子技术有限公司 组合拉曼泵浦源及拉曼放大器
CN209844966U (zh) * 2019-07-12 2019-12-24 无锡瀚诺光电科技有限公司 混合放大器
CN113824502A (zh) * 2021-11-19 2021-12-21 北京邮电大学 一种混合光纤放大器的参数调节方法及混合光纤放大器

Also Published As

Publication number Publication date
CN117080847A (zh) 2023-11-17

Similar Documents

Publication Publication Date Title
US6542290B1 (en) Optical amplifier
Jain et al. 32-core inline multicore fiber amplifier for dense space division multiplexed transmissionsystems
EP3917036A2 (en) Gain equalization in c+l erbium-doped fiber amplifiers
WO2021204006A1 (zh) 一种光纤、光放大器及光通信系统
Tsuchida et al. Amplification characteristics of a multi-core erbium-doped fiber amplifier
WO2003065625A2 (en) Fiber ring amplifiers and lasers
CN116232530A (zh) 光放大系统
EP1788731B1 (en) Optical transmission system and optical filter assembly for submarine applications
US6011644A (en) Hybrid fiber amplifier
CN101908707B (zh) 光放大器和光放大方法
WO2020019661A1 (zh) 一种用于edfa中的双980泵浦激光器对泵结构
CN106170933A (zh) 一种光中继器，及光纤通信系统
JPH04250681A (ja) 多段光学増幅器
JP4411696B2 (ja) 光カプラ、光増幅装置および光通信システム
CN112953640A (zh) 级联遥泵放大系统、远程增益单元及信号光放大方法
WO2023217131A1 (zh) 光放大器、光放大的方法以及光纤通信系统
KR19990005155A (ko) 흡수체를 갖는 광증폭기
US6862132B1 (en) Suppression of double rayleigh backscattering and pump reuse in a raman amplifier
WO2022134109A1 (zh) 一种光纤放大器、波分复用系统及光通信设备
JPH10326930A (ja) 利得平坦化光繊維増幅器
US6504647B1 (en) Optical fiber amplifier, a method of amplifying optical signals, optical communications system
Maeda et al. Propagation direction interleaved cladding pumped 19-core EDFA in L-band
CN201757826U (zh) 一种光放大器
KR100219711B1 (ko) 평탄한 이득특성을 갖는 광섬유증폭기
CN116960714B (zh) 一种光纤放大器

Legal Events

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

Ref document number: 23802900

Country of ref document: EP

Kind code of ref document: A1