The following describes the optical signal amplification apparatus in embodiments of this application with reference to FIG. 2 to FIG. 9.

FIG. 2 is a schematic block diagram of an optical signal amplification apparatus according to an embodiment of this application. As shown in FIG. 2, the optical signal amplification apparatus includes a power detection module 210, a pump control module 220, and a Raman amplification module 230. The optical signal amplification apparatus is applied to a space division multiplexing transmission system. A to-be-transmitted space division multiplexed signal in the space division multiplexing transmission system includes N spatial dimensions, and each spatial dimension includes G wavelength channels, where N is a positive integer, and G is a positive integer. For example, the spatial dimension may include a mode or a fiber core.

The power detection module 210 is configured to: detect power of each of the G wavelength channels in each of the N spatial dimensions to obtain power detection information; determine power configuration information based on the power detection information; and send the power configuration information to the pump control module.

The pump control module 220 is configured to output N channels of pump light, where each channel of pump light includes M pieces of split pump light of different wavelengths, a proportion of each piece of split pump light in pump light of a corresponding wavelength is determined based on the power configuration information, and M is an integer greater than 1.

The Raman amplification module 230 is configured to perform Raman amplification on the space division multiplexed signal in all of the N spatial dimensions by using the N channels of pump light.

In this embodiment of this application, the power detection module 210 detects the power of each wavelength channel in each spatial dimension, to obtain the power detection information (or power distribution information) of each wavelength channel in each spatial dimension, then performs calculation by using the power detection information, to obtain the power configuration information, and feeds back the power configuration information to the pump control module 220. The pump control module 220 is configured to output the N channels of pump light, where each channel of pump light includes M pieces of split pump light of different wavelengths, and a proportion of each piece of split pump light in pump light of a corresponding wavelength is determined based on the power configuration information. In other words, the pump control module 220 adjusts a splitting proportion of pump light of each wavelength based on the power configuration information, so that a pump configuration corresponding to each channel of output pump light is consistent with the power configuration information fed back by the power detection module. The Raman amplification module 230 is configured to perform Raman amplification on the space division multiplexed signal by using the N channels of pump light output by the pump control module. Further, the N channels of pump light correspond to the N spatial dimensions, to provide corresponding pump light for the space division multiplexed signal in each spatial dimension, to perform Raman amplification and power equalization on the space division multiplexed signal. The optical signal amplification apparatus in this embodiment of this application improves transmission performance of the space division multiplexing system, and greatly increases a transmission distance.

It should be understood that an arrow direction in FIG. 2 is merely an example for description, and does not constitute a limitation on this embodiment of this application.

Optionally, that the power detection module 210 is configured to determine power configuration information based on the power detection information includes: the power detection module determines the power configuration information based on the power detection information according to a power flatness criterion. The power flatness criterion may be understood as a criterion for ensuring power equalization of all wavelength channels in each spatial dimension.

The power detection module 210 detects the power of each wavelength channel in each spatial dimension in real time, determines the power configuration information according to the power flatness criterion, and feeds back the power configuration information to the pump control module 220, so that the pump control module 220 dynamically adjusts a splitting coefficient of each channel of pump light.

The power configuration information is used to implement power equalization between spatial wavelength channels. For example, the power configuration information may include one or more target power values. The target power value may be understood as a power compensation value for a wavelength channel in a spatial dimension.

A process in which the power detection module determines the power configuration information is described by using an example. It is assumed that the space division multiplexed signal transmitted in the space division multiplexing system has a plurality of spatial dimensions, and one of the spatial dimensions includes five wavelength channels. The power detection module may obtain a power value of each wavelength channel by performing detection on the five wavelength channels. To implement power equalization or power flattening, a power value of a wavelength channel whose power value is comparatively small in the five wavelength channels may be adjusted up, and a power value of a wavelength channel whose power value is comparatively large may be adjusted down, that is, a power value in the five wavelength channels is adjusted to the target power value. It can be understood that the example herein is merely for ease of understanding, and this application is not limited thereto. For example, a quantity of wavelength channels is not limited. It can be further understood that the example is given herein for a plurality of wavelength channels in only one spatial dimension, but during actual application, this may be extended to wavelength channels in a plurality of spatial dimensions. This is not specifically limited.

Before performing detection on each wavelength channel, the power detection module 210 may first separate each spatial dimension, and further separate each wavelength channel in each spatial dimension. Further, separation of the space division multiplexed signal in the N spatial dimensions may be implemented by using a spatial channel separation module (for example, a space division demultiplexer). Further, the G wavelength channels may be separated by using a wavelength channel power detection module (for example, a wavelength demultiplexer).

Optionally, the power detection module 210 may include the spatial channel separation module and the wavelength channel power detection module. The spatial channel separation module is configured to separate the space division multiplexed signal in the N spatial dimensions. The wavelength channel power detection module is configured to separate the G wavelength channels in each spatial dimension, and detect the power of each wavelength channel.

For example, the spatial channel separation module may be implemented by a space division demultiplexer. It can be understood that this application is not limited thereto, and spatial channel separation may be alternatively implemented by using another device or module having a spatial channel separation function.

For example, the wavelength channel power detection module may be implemented by a wavelength demultiplexer. It can be understood that this application is not limited thereto, and wavelength channel separation and/or detection may be alternatively implemented by using another device or module having a wavelength channel separation function and/or detection function.

Optionally, the power detection module 210 may further include a data collection and processing module. The data collection and processing module is configured to collect and process data output by the wavelength channel power detection module.

FIG. 3 is an example diagram of a power detection module. As shown in FIG. 3, the power detection module includes a spatial channel separation module, a plurality of wavelength channel power detection modules, and a data collection and processing module. The spatial channel separation module demultiplexes light in different spatial dimensions, to separate data in the spatial dimensions. The wavelength channel power detection module is configured to detect a power value of each wavelength channel in each spatial dimension. After an output of the plurality of wavelength channel power detection modules is processed by the data collection and processing module, power configuration information is output. The power detection module feeds back the power configuration information to a pump control module, to adjust splitting coefficients that are allocated by M pump light sources to the N spatial dimensions. For example, the splitting coefficients are represented as (a₁, a₂, . . . , a_M, . . . , k₁, k₂, . . . , k_M).

A source of the to-be-detected space division multiplexed signal is not specifically limited in this application. The space division multiplexed signal detected by the power detection module 210 (that is, the to-be-detected space division multiplexed signal) may be partial signal light separated from a fiber link by using an optical splitting apparatus (for example, an optical splitter).

Optionally, the optical signal amplification apparatus further includes a first optical splitter. The first optical splitter is configured to separate the to-be-detected space division multiplexed signal from a space division multiplexing fiber link. The first optical splitter is connected to the power detection module. The power detection module performs detection on the partial signal light separated by the first optical splitter, to obtain a power status of each wavelength channel in each spatial dimension.

In this embodiment of this application, the pump control module 220 is configured to adjust a pump light splitting coefficient by using the power configuration information obtained from the power detection module 210, to output the N channels of pump light. The following briefly describes the pump control module 220.

Optionally, the pump control module 220 includes M pump light sources of different wavelengths, M optical splitters, and N optical multiplexers. Each optical splitter has one input port and N output ports. Each pump light source is connected to an input port of one optical splitter. N output ports of each optical splitter are connected to one output port in the N optical multiplexers. The M pump light sources are configured to generate M pieces of pump light. Each optical splitter is configured to split pump light of a corresponding wavelength based on a first splitting coefficient, and output N pieces of split pump light through N output ports. The N pieces of split pump light output by each optical splitter arrive at the N optical multiplexers, respectively. The N optical multiplexers are configured to output the N channels of pump light. Each optical multiplexer is configured to perform, based on a second splitting coefficient, beam combining on M pieces of split pump light obtained from the M optical splitters, to obtain one channel of pump light. The first splitting coefficient and/or the second splitting coefficient are/is determined based on the power configuration information.

The pump light source is configured to generate pump light. For example, the pump light source may be implemented by a pump laser.

It can be understood that the pump laser is merely one possible implementation thereof, and this application is not limited thereto. A person skilled in the art may replace the pump laser with another apparatus that can generate pump light. For example, a 980 nanometer (nm) laser diode may be used as the pump light source.

The M pump light sources of the different wavelengths are configured to generate the M pieces of pump light of the different wavelengths. It is assumed that the wavelengths corresponding to the M pieces of pump light are represented as λ₁, λ₂, . . . , and λ_M, and output powers corresponding to the pump light of the wavelengths are represented as P_λ1, P_λ2, . . . , and P_λM. In this case, a power of pump light output by each optical multiplexer is a weighted sum of powers of M pieces of split pump light. For example, a pump power of an optical multiplexer 1 is a₁P_λ1+a₂P_λ2+ . . . a_MP_λM, where a_iP_λiis a pump power corresponding to a wavelength λ_iafter optical splitting, . . . , and a pump power of an optical multiplexer N is k₁P_λ1+k₂P_λ2+ . . . k_MP_λM. In other words, powers of the N channels of pump light output by the N optical multiplexers may be represented as (a₁P_λ1+a₂P_λ2+ . . . a_MP_λM, . . . , k₁P_λ1+k₂P_λ2+ . . . k_MP_λM). Splitting coefficients corresponding to the powers of the N channels of pump light may be represented as (a₁, a₂, . . . , a_M, . . . , k₁, k₂, . . . , k_M).

In this embodiment of this application, the splitting coefficient corresponding to the power of the N channels of pump light output by the pump control module 220 is determined based on the power configuration information. The splitting coefficient corresponding to the power of the N channels of pump light may be adjusted in the following two stages: a first stage in which the optical splitter splits pump light of each wavelength, and a second stage in which the optical multiplexer performs beam combining on a plurality of pieces of split pump light. The pump control module may obtain the N channels of pump light (or adjust the splitting coefficient in the foregoing two stages) by using different implementations. For ease of description, the first splitting coefficient (corresponding to the first stage) and the second splitting coefficient (corresponding to the second stage) are introduced for description.

Implementation 1:

The first splitting coefficient is determined based on the power configuration information. The pump control module 220 allocates a pump light power of a corresponding wavelength to N output ports of a tunable optical splitter based on the first splitting coefficient by using the tunable optical splitter. In other words, the pump control module determines the first splitting coefficient based on the power configuration information, and adjusts the tunable optical splitter based on the first splitting coefficient.

In the implementation 1, a function of the power configuration information is embodied in each tunable optical splitter, and only simple weighted summation needs to be performed on the M pieces of split pump light at the optical multiplexer. In this case, correspondingly, the second splitting coefficient is a weighting coefficient (or a weight value), and a value of each weighting coefficient is 1.

Further, the pump control module 220 includes the M pump light sources of the different wavelengths (λ₁, λ₂, . . . , λ_M), the M tunable optical splitters, and the N optical multiplexers. Each optical splitter has one input port and N optical-splitting output ports. The input port is connected to one pump light source of a specific wavelength. A splitting proportion of the N output ports (that is, the first splitting coefficient) may be adjusted based on the power configuration information. The N pieces of split pump light output by each optical splitter arrive at the N optical multiplexers, respectively. Each optical multiplexer obtains split pump light output by all of the M optical splitters, that is, M pieces of split pump light. Each optical multiplexer is configured to perform, based on the second splitting coefficient, beam combining on the M pieces of split pump light obtained from the M optical splitters, to obtain one channel of pump light. In other words, an output of each optical multiplexer is a weighted sum of powers of the M pieces of split pump light (where the weighting coefficient is 1).

The first splitting coefficient generally refers to a splitting coefficient (or splitting proportion) adjusted by using the optical splitter. In addition, values of first splitting coefficients respectively corresponding to different optical splitters may be the same or may be different. This is not specifically limited in this application. A first splitting coefficient corresponding to one optical splitter may include one or more values. This is not limited.

For example, a pump power of an optical multiplexer 1 is a a₁P_λ1+a₂P_λ2+ . . . a_MP_λM, where a_iP_λiis a pump power corresponding to a wavelength λ_iafter optical splitting, . . . , and a pump power of an optical multiplexer N is k₁P_λ1+k₂P_λ2+ . . . k_MP_λM. Correspondingly, a first splitting coefficient corresponding to an optical splitter 1 is (a₁, . . . , k₁), and a first splitting coefficient corresponding to an optical splitter M is (a_M, . . . , k_M).

For ease of understanding, the pump control module corresponding to the implementation 1 is described herein with reference to FIG. 4. For ease of description, an optical pump unit, an optical splitting unit, and an optical multiplexer unit are introduced herein. As shown in FIG. 4, the pump control module includes three parts: the optical pump unit, the optical splitting unit, and the optical multiplexer unit. The optical pump unit includes M pump lasers of different wavelengths (λ₁, λ₂, . . . , λ_M). The optical splitting unit includes M tunable optical splitters. Each optical splitter has one input port and N optical-splitting output ports. The input port is connected to one pump laser of a specific wavelength. A splitting proportion of the N output ports may be adjusted at will. The optical multiplexer unit includes N optical multiplexers. Each optical multiplexer performs beam combining on powers of pump light of the M wavelengths obtained through optical splitting, that is, an output of each optical multiplexer is a weighted sum of the powers of the pump light of the M wavelengths. For example, a pump light power output by an optical multiplexer 1 is a₁P_λ1+a₂P_λ2+ . . . a_MP_λM, . . . , and a pump light power output by an optical multiplexer N is k₁P_λ1+k₂P_λ2+ . . . k_MP_λM.

Implementation 2:

The second splitting coefficient is determined based on the power configuration information. The pump control module adjusts a proportion of split pump light of each wavelength at the optical multiplexer by using the second splitting coefficient, and finally outputs the N channels of pump light. In other words, the pump control module determines the second splitting coefficient based on the power configuration information, and performs beam combining on split pump light of different wavelengths based on the second splitting coefficient.

In the implementation 2, the pump light of the corresponding wavelength merely needs to be equally split at the uniform optical splitter, and a function of the power configuration information is embodied in the optical multiplexer.

Further, the pump control module includes the M pump light sources of the different wavelengths (λ₁, λ₂, . . . , λ_M), the M uniform optical splitters, and the N optical multiplexers. Each optical splitter has one input port and N optical-splitting output ports. The input port is connected to one pump light source of a specific wavelength. Each optical splitter splits a power of pump light of a corresponding wavelength into N equal parts, to obtain N pieces of split pump light whose powers are the same. The N pieces of split pump light output by each optical splitter arrive at the N optical multiplexers, respectively. Each optical multiplexer obtains split pump light output by all of the M uniform optical splitters, that is, M pieces of split pump light. Each optical multiplexer is configured to perform, based on the second splitting coefficient, beam combining on the M pieces of split pump light obtained from the M optical splitters, to obtain one channel of pump light. In other words, an output of each optical multiplexer is a weighted sum of powers of the M pieces of split pump light (where a weighting coefficient used for weighting is the second splitting coefficient, and is determined based on the power configuration information).

A difference from the implementation 1 lies in that, in the implementation 2, a first splitting coefficient corresponding to each uniform optical splitter is determined by equally splitting pump light of a corresponding wavelength, and the second splitting coefficient is determined based on the power configuration information.

For example, a pump power of an optical multiplexer 1 is a₁P_λ1+a₂P_λ2+ . . . a_MP_λM, where a_iP_λiis a pump power corresponding to a wavelength λ_iafter optical splitting, . . . , and a pump power of an optical multiplexer N is k₁P_λ1+k₂P_λ2+ . . . k_MP_λM. Correspondingly, a second splitting coefficient corresponding to the optical multiplexer 1 is (a₁, a₂, . . . , a_M), . . . , and a second splitting coefficient corresponding to the optical multiplexer N is (k₁, k₂, . . . , k_M).

In the implementation 2, optionally, the N optical multiplexers implement the second splitting coefficient by using a wavelength selective switch or an optical cross-connect device.

For ease of understanding, the pump control module corresponding to the implementation 2 is described herein with reference to FIG. 5. For ease of description, an optical pump unit, an optical splitting unit, and an optical cross-connect unit are introduced herein. As shown in FIG. 5, the pump control module includes three parts: the optical pump unit, the optical splitting unit, and the optical cross-connect unit. The optical pump unit includes M pump lasers of the different wavelengths (λ₁, λ₂, . . . , λ_M). The optical splitting unit includes M uniform optical splitters, where each optical splitter splits a power of one piece of pump light of a specific wavelength into n equal parts (P_λ1/n, P_λ2/n, . . . , P_λM/n). In other words, the first splitting coefficient is 1/n. The optical cross-connect unit has N output ports. The optical cross-connect unit cross-connects split optical signals by using the wavelength selective switch or the optical cross-connect device, flexibly adjusts a proportion of each wavelength component, performs optical multiplexing, and finally outputs the weighted N channels of light as pump light in different modes. Pump light of an output port 1 of the optical cross-connect unit is a₁P_λ1+a₂P_λ2+ . . . a_MP_λM, . . . , and pump light of an output port N of the optical cross-connect unit is k₁P_λ1+k₂P_λ2+ . . . k_MP_λM, where a₁, a₂, . . . , a_M, . . . , k₁, k₂, . . . , and k_Mare different splitting coefficients. In other words, the optical cross-connect unit may be considered as N optical multiplexers, where each optical multiplexer corresponds to one output port of the optical cross-connect unit.

Implementation 3:

The implementation 3 is an implementation combining the foregoing two implementations. Both the first splitting coefficient and the second splitting coefficient are determined based on the power configuration information. In other words, in the implementation 3, a function of the power configuration information is embodied in both the optical splitter and the optical multiplexer.

The pump control module allocates, by using a tunable optical splitter, a pump light power of a corresponding wavelength to N output ports of the tunable optical splitter based on the first splitting coefficient (where the first splitting coefficient is not obtained through equal splitting), and performs beam combining at the optical multiplexer based on the second splitting coefficient (where a value of the second splitting coefficient is not 1), to finally output the N channels of pump light. Certainly, the N channels of pump light herein may also be represented as a₁P_λ1+a₂P_λ2+ . . . a_MP_λM, . . . , and k₁P_λ1+k₂P_λ2+ . . . k_MP_λM.

Through the foregoing three implementations, the pump control module can dynamically adjust gains of different channels in different spatial dimensions, to compensate for a DMG generated after signal light passes through an EDFA, thereby implementing gain equalization of different channels in different spatial dimensions.

The Raman amplification module 230 is configured to perform, by using the N channels of pump light obtained from the pump control module 220, Raman amplification on signal light transmitted in an optical fiber. The following describes the Raman amplification module 230.

Optionally, the Raman amplification module 230 includes a space division multiplexer and a space division multiplexing fiber. The N channels of pump light are coupled to the space division multiplexing fiber through the space division multiplexer, and the space division multiplexed signal transmitted in the space division multiplexing fiber undergoes stimulated Raman amplification under the action of the N channels of pump light. FIG. 6 is an example diagram of a Raman amplification module according to an embodiment of this application. As shown in FIG. 6, the N channels of pump light output by the pump control module are coupled into the space division multiplexing fiber through the space division multiplexer, and the space division multiplexed signal transmitted in the optical fiber is subjected to the pump light, thereby generating stimulated Raman amplification. The splitting coefficients (a₁, a₂, . . . , a_M, . . . , k₁, k₂, . . . , k_M) corresponding to the N channels of pump light are adjustable (that is, the pump control module performs adjustment based on the power configuration information), to implement a power equalization between spatial wavelength channels.

The space division multiplexer in this embodiment of this application may be a mode multiplexer, a fiber core multiplexer, or a multiplexer in another dimension. This is not specifically limited.

The optical signal amplification apparatus in embodiments of this application may be applied to a plurality of types of optical communications systems, for example, a single-mode fiber transmission system, a few-mode fiber transmission system, and a multimode fiber transmission system, and is applicable to a comparatively wide range of scenarios.

In a possible implementation, the optical signal amplification apparatus in this application may be cascaded with and used in combination with a space division multiplexing EDFA. FIG. 7 is a schematic diagram of a structure of a hybrid Raman/EDFA space division multiplexing fiber amplifier according to an embodiment of this application. As shown in FIG. 7, the structure includes a power detection module, a pump control module, a Raman amplification module (which includes a space division multiplexing fiber and a space division multiplexer, and optionally, may further include a dichroic mirror), a space division multiplexing EDFA, and an optical splitting apparatus. In FIG. 7, pump light is coupled to the space division multiplexing EDFA through one dichroic mirror. A space division multiplexed optical signal amplified by the space division multiplexing EDFA is split by one optical splitting apparatus (for example, a first optical splitter), and partial light obtained through the splitting is transmitted to the power detection module. After obtaining a partial space division multiplexed optical signal from the optical splitting apparatus, the power detection module detects power (power detection information) of each wavelength channel in each spatial dimension, performs calculation on the power detection information to obtain power configuration information, and then feeds back the power configuration information to the pump control module. The pump control module adjusts splitting coefficients of pump light of different wavelengths based on the power configuration information transferred by the power detection module, and outputs N channels of pump light. The Raman amplification module performs beam combining on the N channels of pump light by using the space division multiplexer, and inputs, to the space division multiplexing fiber, pump light obtained through beam combining, to compensate for power unflatness of wavelength channels in each spatial dimension.

In a possible implementation, the optical signal amplification apparatus in this embodiment of this application may be applied to a few-mode fiber transmission system (for example, a few-mode fiber C+L-band transmission system). The optical signal amplification apparatus further includes N phase plates. The N phase plates are disposed between the pump control module and the Raman amplification module. The N phase plates are configured to load, to corresponding modes, the N channels of pump light output by the pump control module, where the N spatial dimensions include N modes. Different modes may be understood as different distributions of light energy.

With reference to FIG. 8, the following describes an optical signal amplification apparatus applied to a few-mode fiber C+L-band transmission system. FIG. 8 is a schematic diagram of a structure of a hybrid Raman/EDFA-based C+L-band few-mode fiber amplifier. As shown in FIG. 8, the fiber amplifier includes a few-mode fiber FMF, two dichroic mirrors, a C-band and L-band few-mode fiber amplifier EDFA structure (which specifically includes a C-band few-mode erbium-doped fiber (C-FM-EDF) and an L-band few-mode erbium-doped fiber (L-FM-EDF), an optical demultiplexing apparatus, and an optical multiplexing apparatus), an optical splitting apparatus (for example, a first optical splitter), a power detection module, a pump control module, and N phase plates. The N phase plates, the few-mode fiber FMF, and the dichroic mirror may constitute a Raman amplification module. In FIG. 8, a pump light source (which may be specifically a pump laser, for example, a 980 nm pump laser) pumps a few-mode EDFA. Pump light generated by the pump light source is coupled to C-band and L-band few-mode EDFAs through the dichroic mirror. Because structures of the C-band and L-band few-mode EDFAs are different, to implement C+L-band broadband gain amplification, optical demultiplexing may be performed on signal light, and then signal light obtained through the optical demultiplexing is respectively amplified by the few-mode EDFAs of corresponding bands (namely, the C-FM-EDF and the L-FM-EDF). Through the optical multiplexing apparatus, optical multiplexing is performed on signal light amplified by the C-band and L-band few-mode EDFAs. Signal light obtained through optical multiplexing is split by the optical splitting apparatus, and partial signal light obtained through the splitting is transmitted to the power detection module. The power detection module detects a power status (or a gain status) of each wavelength channel in each mode, determines power configuration information (or gain information), and finally feeds back the configuration information to the pump control module. The pump control module performs power adjustment, that is, adjusts ratios (or splitting coefficients) of pump light at different wavelengths, based on the power configuration information sent by the power detection module. The pump control module outputs N channels of pump light. The N channels of pump light are loaded to corresponding N modes by using the N phase plates. Different phase plates correspond to different modes. It can be learned from FIG. 8 that different modes correspond to different light energy distributions (or cross-sections). Beam combining is performed on pump light in each mode, and then pump light obtained through the beam combining is injected into the few-mode fiber FMF through the dichroic mirrors, thereby pumping the FMF, to implement Raman amplification. The hybrid Raman/EDFA-based C+L-band few-mode fiber amplifier in FIG. 8 can implement Raman amplification for the C and L bands at the same time, and can compensate for gains at different channels in different FM-EDFA modes, thereby implementing mode channel equalization for the C and L bands.

It can be understood that the structure in FIG. 8 is merely an example for description, and this application is not limited thereto. For example, some components in FIG. 8 may be properly replaced with other components.

In a possible implementation, the optical signal amplification apparatus in this embodiment of this application may be applied to a multi-core fiber transmission system. The optical signal amplification apparatus further includes a multi-core fan-in module. The multi-core fan-in module is disposed between the pump control module and the Raman amplification module. The multi-core fan-in module is configured to inject, into corresponding fiber cores, the N channels of pump light output by the pump control module, where the N spatial dimensions include N fiber cores.

With reference to FIG. 9, the following describes an optical signal amplification apparatus applied to a multi-core fiber transmission system. FIG. 9 is a schematic diagram of a structure of an optical fiber amplifier based on a multi-core fiber transmission system. As shown in FIG. 9, the optical fiber amplifier includes a multi-core fiber, two dichroic mirrors, a pump (which may be specifically a pump laser, for example, a 980 nm pump laser), a multi-core erbium-doped fiber amplifier EDFA (which includes a multi-core erbium-doped fiber), an optical splitting apparatus, a power detection module, a pump control module, and a multi-core fan-in module. The multi-core fan-in module, the multi-core fiber, and the dichroic mirror may constitute a Raman amplification module. Pump light generated by the pump laser is used as an example. The pump light is coupled to the multi-core EDFA through one dichroic mirror. The multi-core EDFA amplifies signal light. Signal light obtained through gain amplification by the multi-core EDFA is split by one optical splitting apparatus, and partial signal light obtained through the splitting is transmitted to the power detection module. After receiving the partial signal light transmitted by the optical splitting apparatus, the power detection module detects power of each wavelength channel of each fiber core to obtain power detection information, determines power configuration information based on the power detection information, and finally feeds back the power configuration information to the pump control module. The pump control module adjusts a pump light configuration based on the power configuration information fed back by the power detection module, and outputs N channels of pump light. The Raman amplification module injects the N channels of pump light into corresponding fiber cores through the multi-core fan-in module and a dichroic mirror apparatus, to perform Raman amplification on signal light transmitted in the corresponding fiber cores. The optical fiber amplifier in FIG. 9 can implement multi-core channel equalization by compensating for gains at different channels of different fiber cores in the multi-core EDFA.

It can be understood that the structure in FIG. 9 is merely an example for description, and this application is not limited thereto. For example, some components in FIG. 9 may be properly replaced with other components.

It can be further understood that the examples in FIG. 7 to FIG. 9 in embodiments of this application are merely intended to help a person skilled in the art understand embodiments of this application, but are not intended to limit embodiments of this application to specific scenarios in the examples. A person skilled in the art may make various equivalent modifications or changes based on the examples in FIG. 7 to FIG. 9, and such modifications or changes also fall within the scope of embodiments of this application.

Based on the foregoing optical signal amplification apparatus, this application further provides an optical signal amplification method. FIG. 10 is a schematic flowchart of an optical signal amplification method 1000 according to an embodiment of this application. The optical signal amplification method