Optical multiplexing segment, optical communication system, and optical amplifier

Abstract

The invention provides an optical multiplexing section, an optical communication system and an optical amplifier, and belongs to the technical field of optical communication. The optical multiplexing section comprises a first wave combining and dividing module, an optical amplifier and a second wave combining and dividing module, wherein the optical amplifier is located between the first wave combining and dividing module and the second wave combining and dividing module. A target light beam with the wavelength different from that of each path of service signal light exists in the optical amplifier, the target light beam has gain in the optical amplifier, and the gain is lower than that of at least one path of service signal light transmitted by the optical multiplexing section in the optical amplifier, so that the target light beam and the service signal light jointly participate in gain calculation of the optical amplifier. The gain of the at least one path of service signal light is higher than that of the at least one path of service signal light when the target light beam is transmitted in the optical amplifier, so that the power fluctuation of the at least one path of service signal light after wave addition is reduced, the wavelength of the addition wave does not need to be detected, and the transient response of the addition wave has no delay.

Description

Technical Field

[0001] This application relates to the field of optical communication technology, and in particular to an optical multiplexer, an optical communication system, and an optical amplifier. Background Technology

[0002] With the continuous development of applications such as cloud computing and the Internet of Things, data traffic is growing rapidly. To cope with this surge in data traffic, optical transport networks are generally used. An optical transport network consists of multiple optical multiplex sections (OMS), each including a first multiplexing / demultiplexing module, an optical amplifier (OA), and a second multiplexing / demultiplexing module, with the OA located between the first and second modules. In these multiplexing / demultiplexing sections, due to faults, service wavelengths are frequently rescheduled. For example, an upstream link failure may reduce the number of service wavelengths in the downstream link, or some service wavelengths may have their paths changed, resulting in a reduction in the original path's service wavelengths—a phenomenon known as wavelength drop. After a wavelength drop occurs, the performance of other service wavelengths deteriorates, primarily manifested as power fluctuations. Summary of the Invention

[0003] This application provides an optical multiplexing section, an optical communication system, and an optical amplifier, which can reduce the performance degradation of service signal light after wavelength reduction. The technical solution adopted is as follows:

[0004] In a first aspect, this application provides an optical multiplexing section, which includes a first multiplexing / demultiplexing module, an optical amplifier, and a second multiplexing / demultiplexing module, with the optical amplifier located between the first and second multiplexing / demultiplexing modules. The first multiplexing / demultiplexing module is used to receive and output target service signal light, the optical amplifier is used to amplify and output the target service signal light and the target beam, the target beam has a different wavelength than each service signal light transmitted by the optical multiplexing section, the target beam has gain in the optical amplifier, and the gain is lower than the gain of at least one service signal light in the optical amplifier, and the second multiplexing / demultiplexing module is used to output the amplified target service signal light.

[0005] In the scheme shown in this application, in the optical multiplexing section, there is a target beam with a wavelength different from that of each service signal light in the optical amplifier. The target beam has a gain in the optical amplifier, so that the target beam and the service signal light jointly participate in the gain calculation of the optical amplifier. Since the gain of the target beam is lower than the gain of at least one service signal light in the optical amplifier, and the gain of the optical amplifier is constant, the gain of the at least one service signal light is higher when the target beam is transmitted in the optical amplifier than when there is no target beam, thereby reducing the power fluctuation of the at least one service signal light after the ripple effect is added. Moreover, since the wavelength of the target beam is independent of the ripple effect, there is no need to detect the wavelength of the service signal light after the ripple effect is added, so that the optical amplifier does not need to perform the ripple effect detection operation after the ripple effect is added, thereby making the transient response of the ripple effect without delay.

[0006] In one alternative approach, the target beam has a gain in the optical amplifier, and this gain is lower than the gain of each service signal beam in the optical amplifier. Thus, the gain of each service signal beam is higher when the target beam is transmitted in the optical amplifier than when there is no target beam, thereby reducing power fluctuations in each service signal beam after wavelet addition.

[0007] In one alternative approach, the target beam is provided by a separate module; that is, the optical multiplexing section includes an optical supply module that outputs the target beam to the optical amplifier. This facilitates control over the power of the target beam.

[0008] In one alternative approach, the target beam is coupled to the optical amplifier by a first multiplexing / splitting module. Specifically, the first multiplexing / splitting module receives the target beam from the optical supply module, combines the target beam and the target service signal light into a single optical signal, and outputs it to the first optical amplifier. This eliminates the need for an additional multiplexing module in the optical multiplexing section, simplifying its structure.

[0009] In one alternative approach, the target beam is coupled to an optical amplifier by a multiplexing module. The optical multiplexing section includes M multiplexing modules, where M is less than or equal to the number of optical amplifiers. Each multiplexing module is connected to the input of an optical amplifier. Each multiplexing module receives the target beam from the optical supply module, combines the target beam and the target service signal light into a single optical signal, and outputs it to the connected optical amplifier. This allows for flexible introduction of the target beam into the optical multiplexing section.

[0010] In one alternative approach, a multiplexing module is included in the optical multiplexing section. This multiplexing module guides the target beam into the first optical amplifier until it reaches the end of the optical multiplexing section. In this way, the optical amplifiers throughout the optical multiplexing section share the target beam, simplifying the structure of the optical multiplexing section.

[0011] In one alternative approach, the target beam is transmitted only within an optical multiplexing segment, which further includes P first wavelength division multiplexing (WDM) modules, where P is less than or equal to M. Each WDM module is located between two adjacent optical amplifiers, with the input of the latter amplifier connected to a multiplexing module, or the first WDM module is connected to the output of the last optical amplifier. The first WDM module blocks the received target beam, preventing it from being transmitted along with the service signal light.

[0012] In one alternative approach, the target beam is transmitted only within one optical multiplexing section. The second multiplexing / demultiplexing module is responsible for blocking the received target beam, preventing it from continuing to be transmitted along with the service signal light. This eliminates the need for additional wavelength division multiplexing modules, thus simplifying the structure of the optical multiplexing section.

[0013] In one alternative approach, the target beam comprises amplified spontaneous emission (ASE) light generated by an optical amplifier, thus eliminating the need for an additional light source.

[0014] In one alternative approach, in the optical multiplexing section, there are multiple optical amplifiers, and the target beam includes ASE light generated by the first optical amplifier, which is transmitted throughout the optical multiplexing section.

[0015] In one alternative embodiment, when the target beam includes ASE light generated by a first optical amplifier, the optical multiplexing section further includes a multiplexing module and a second wavelength division multiplexing module. The multiplexing module is connected to the second wavelength division multiplexing module, and the multiplexing module is connected to the input of the first optical amplifier. The second wavelength division multiplexing module is connected to the output of the first optical amplifier. The multiplexing module receives the target service signal light from the first multiplexing / demultiplexing module and outputs the target service signal light to the first optical amplifier. During the amplification of the target service signal light, the first optical amplifier generates ASE light and outputs amplified target service signal light and ASE light to the second wavelength division multiplexing module. The second wavelength division multiplexing module receives the ASE light output from the first optical amplifier and the amplified target service signal light. It outputs a portion of the received ASE light to the multiplexing module for further amplification, and another portion of the ASE light and the amplified target service signal light to the second multiplexing / demultiplexing module, allowing subsequent optical amplifiers to use this other portion of ASE light. The multiplexing module outputs the received ASE light to the first optical amplifier. In this way, the entire optical multiplexing band uses the ASE light generated by the first optical amplifier.

[0016] In one alternative approach, the ASE light is transmitted only within its respective optical multiplexing section. The second multiplexing / demultiplexing module blocks the received ASE light. Alternatively, a third demultiplexing module exists in the optical multiplexing section. The third demultiplexing module is connected to the output of the last optical amplifier. The third demultiplexing module blocks the received ASE light and outputs the received target service signal light, allowing the target service signal light to continue transmitting while the ASE light stops transmitting.

[0017] In one alternative approach, when there are multiple optical amplifiers, the target beam also includes the ASE light generated by the optical amplifier in the previous optical multiplexing segment. This allows the ASE light from the previous optical multiplexing segment to be reused.

[0018] In one alternative approach, the optical multiplexing section uses the ASE light generated by the preceding optical multiplexing section. The optical multiplexing section also includes a multiplexing module and a second wavelength division multiplexing module. The multiplexing module is connected to the input of the i-th optical amplifier, and the second wavelength division multiplexing module is connected to the output of the i-th optical amplifier, where i is greater than 1. The first multiplexing / demultiplexing module receives the ASE light from the preceding optical multiplexing section and also receives the target service signal light. It outputs the target service signal light and the ASE light to the first optical amplifier. The target beam used in the first to (i-1)-th optical amplifiers is the ASE light received from the preceding optical multiplexing section. For the i-th to the last optical amplifier, the target beam used is the ASE light generated by the i-th optical amplifier. That is, the multiplexing module receives the amplified target service signal light and outputs the received target service signal light to the i-th optical amplifier. The i-th optical amplifier amplifies the received target service signal light, generating ASE light during the amplification process. It then outputs the ASE light and the amplified target service signal light to the second wavelength division multiplexing module. The second wavelength division module returns a portion of the ASE light to the multiplexing module, where it re-enters the i-th optical amplifier for amplification. It then transmits the remaining ASE light and the amplified target service signal light through the optical multiplexing section. After reaching the second multiplexing / demultiplexing module, this module outputs the received ASE light and amplified target service signal light to the next optical multiplexing section, allowing some optical amplifiers in that section to use the ASE light. Thus, the multiplexing module, the first wavelength division module, and the optical amplifiers form an oscillation unit that outputs ASE light to improve the gain of the service signal light.

[0019] In one alternative approach, the power of the ASE light returning to the optical amplifier may be relatively high, so an attenuator is placed between the multiplexing module and the second splitting module to control the power of the ASE light returning to the optical amplifier.

[0020] In one alternative approach, the multiplexing module and the second demultiplexing module can be combined in several ways. Several feasible combinations are provided below: the multiplexing module includes a coupler and a filter, and the second demultiplexing module is a coupler; or, the multiplexing module is a coupler, and the second demultiplexing module includes a coupler and a filter; or, the multiplexing module is a coupler, and the second demultiplexing module is a wavelength division multiplexer; or, the multiplexing module is a wavelength division multiplexer, and the second demultiplexing module is a coupler.

[0021] In one alternative approach, to facilitate control of the target beam's power, the target beam is transmitted in at most two adjacent optical multiplexing segments.

[0022] In one alternative approach, the wavelength range of each service signal light is from a first value to a second value. In order to better improve the power fluctuation of the service signal light, the wavelength of the target beam is from the first value minus 10 nm to the first value, and / or from the second value to the second value plus 10 nm.

[0023] In one alternative approach, to better improve the power fluctuation of the service signal light, the nominal input power of each optical amplifier is a third value, and the power of the target beam input to each optical amplifier is the third value plus 20 dBm.

[0024] In one alternative approach, to detect the performance of the transmission fiber in the optical multiplexing section, fiber interface units (FIUs) are set on both sides of the transmission fiber. The performance of the transmission fiber, including but not limited to transmission loss, is detected through the fiber interface units.

[0025] Secondly, this application provides an optical communication system comprising multiple optical multiplexing segments as described in the first aspect or any optional method of the first aspect, wherein the multiple optical multiplexing segments are connected in series for providing transmission services for services.

[0026] Thirdly, this application provides an optical amplifier applied to an optical multiplexing section. The optical amplifier is used to receive a target service signal light and a target beam, amplify the target service signal light and the target beam and output them. The target beam has a different wavelength from each service signal light transmitted by the optical multiplexing section. The target beam has a gain in the optical amplifier, and the gain is lower than the gain of at least one service signal light transmitted by the optical multiplexing section in the optical amplifier.

[0027] In the scheme shown in this application, a target beam with a wavelength different from that of each service signal light exists in the optical amplifier. The target beam has a gain in the optical amplifier, so that the target beam and the service signal light jointly participate in the gain calculation of the optical amplifier. Since the gain of the target beam is lower than the gain of at least one service signal light in the optical amplifier, and the gain of the optical amplifier is constant, the gain of the at least one service signal light is higher when the target beam is transmitted in the optical amplifier than when there is no target beam, thereby reducing the power fluctuation of the at least one service signal light after the addition and subtraction of the waveform. Moreover, since the wavelength of the target beam is independent of the wavelength of the added and subtraction of the waveform, there is no need to detect the wavelength of the service signal light after the addition and subtraction of the waveform. Therefore, the optical amplifier does not need to perform the addition and subtraction detection operation after the addition and subtraction of the waveform, thus making the transient response of the addition and subtraction of the waveform without delay. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of an optical transport network provided in an exemplary embodiment of this application;

[0029] Figure 2 This is a schematic diagram of a fault in an optical transport network provided in an exemplary embodiment of this application;

[0030] Figure 3 This is a schematic diagram of an optical multiplexing segment provided in an exemplary embodiment of this application;

[0031] Figure 4 This is a schematic diagram of an optical multiplexer segment employing an optical providing module, provided in an exemplary embodiment of this application;

[0032] Figure 5 This is another schematic diagram of an optical multiplexer segment employing an optical providing module, provided in an exemplary embodiment of this application;

[0033] Figure 6 This is yet another schematic diagram of an optical multiplexer segment employing an optical providing module, provided in an exemplary embodiment of this application;

[0034] Figure 7 This is another schematic diagram of an optical multiplexer segment employing an optical providing module provided in an exemplary embodiment of this application;

[0035] Figure 8 This is another schematic diagram of an optical multiplexer segment employing an optical providing module provided in an exemplary embodiment of this application;

[0036] Figure 9 This is a schematic diagram of an optical multiplexer segment using ASE light provided in an exemplary embodiment of this application;

[0037] Figure 10 This is another schematic diagram of an optical multiplexer segment using ASE light provided in an exemplary embodiment of this application;

[0038] Figure 11 This is yet another schematic diagram of an optical multiplexer segment employing ASE light provided in an exemplary embodiment of this application;

[0039] Figure 12 This is a schematic diagram of an oscillation unit composed of an optical amplifier provided in an exemplary embodiment of this application;

[0040] Figure 13 This is a schematic diagram illustrating the attenuation of ASE light provided in an exemplary embodiment of this application;

[0041] Figure 14 This is a schematic diagram of detecting a transmission optical fiber according to an exemplary embodiment of this application.

[0042] Illustration

[0043] 1. First multiplexing / demultiplexing module; 2. Optical amplifier; 3. Second multiplexing / demultiplexing module; 4. Optical supply module; 5. Multiplexing module; 6. First demultiplexing module; 7. Second demultiplexing module; 8. Third demultiplexing module; 9. Attenuator; 10. Fiber optic interface unit. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0045] The following explains some terms and concepts involved in the embodiments of this application.

[0046] 1. The optical multiplexing section is a transmission structure that enables the complete network transmission of multi-wavelength signals. It is responsible for selecting routes and allocating wavelengths for customer service signals, completing end-to-end optical channel networking. The optical multiplexing section includes two wavelength-selective switches (WSS) or wavelength division multiplexers (WDMs). The optical amplifiers are either doped fiber amplifiers or semiconductor laser amplifiers. The optical amplifiers and transmission fibers are located between the two WSS modules. There may be one or more optical amplifiers, and their functions may differ depending on their location. For example, an optical amplifier at the beginning of the transmission fiber may compensate for insertion loss, while an optical amplifier at the end of the transmission fiber may compensate for fiber loss.

[0047] For example, an optical transport network includes multiple optical multiplexing sections, such as... Figure 1As shown, the optical transport network includes multiple reconfigurable optical add-drop multiplexers (ROADMs), which are connected by transmission optical fibers. Assuming that the first ROADM and the second ROADM are adjacent, the optical multiplexing section includes a multiplexing / demultiplexing module in the first ROADM, a multiplexing / demultiplexing module in the second ROADM, a transmission optical fiber between the first ROADM and the second ROADM, and an optical amplifier.

[0048] 2. An optical amplifier is an optical module that amplifies the power of a weak input signal, compensating for the decrease in optical power caused by transmission loss or insertion loss, and maintaining the transmission of the optical signal in the optical transport network. Its main components are: passive optical devices (couplers, wavelength division multiplexers, isolators, and gain flattening filters, etc.) and doped optical fibers, which can include erbium-doped fiber or ytterbium-doped fiber, etc.

[0049] With the continuous emergence of applications such as 5G, cloud computing, artificial intelligence (AI), the Internet of Things (IoT), and augmented reality (AR) or virtual reality (VR), the demand for data traffic transmission is accelerating. To meet these transmission demands, communication networks need to be expanded. Wavelength division multiplexing (WDM) systems are one of the key measures to achieve this expansion. In optical transport networks using WDM systems, due to expansion needs or fault occurrences, there are often active or passive scheduling phenomena for service wavelengths. For example, a) when expanding service wavelengths, several channels are actively added to the current network, i.e., active wavelength addition, where each channel corresponds to a specific wavelength; b) upstream link failures lead to a reduction in the number of channels in the downstream link, i.e., passive wavelength drop; c) some channels change paths, reducing the number of channels in the original path, i.e., active wavelength drop, which actively reduces the wavelength of the service signal light. Whether it is active switching or passive addition or removal of wavelengths (i.e., adding or removing wavelengths), it will cause changes in the performance of signal light of other wavelengths, mainly reflected in the reduction of power, which will lead to the degradation of optical signal-noise ratio (OSNR), and thus affect the bit error rate of the signal at the receiving end.

[0050] Furthermore, with the expansion of the spectrum, the degree of mutual influence between channels in a WDM system increases significantly. For example, compared to a conventional (C) band WDM system, in a C+ long (L) band system, the remaining channels are more severely affected by the changing channels during active or passive addition or removal of wavelengths. The channels that are added or removed are called changing channels, and the channels that do not change are called remaining channels. The main reasons include the following three points.

[0051] 1) Gain competition: Before and after adding or removing waves, the optical amplifier in the WDM system automatically identifies the input optical power and adjusts the pump light based on the optical power, which in turn causes the population inversion rate to change. The gain spectrum of the doped fiber in the optical amplifier will change significantly with the change in the population inversion rate, which will cause the power and OSNR of the signal light in the remaining channels to change.

[0052] 2) Spectral hole burning (SHB): Optical amplifiers are generally doped fiber amplifiers. The gain spectrum of doped fibers exhibits non-uniform broadening characteristics, which causes a hole burning effect of varying amplitude at different wavelengths. The degree of hole burning is related to the power proportion of the channel in the holed region; therefore, the intensity of the hole burning effect is strongly correlated with the channel combination.

[0053] 3) Stimulated Raman scattering (SRS): In optical multiplexing sections, which include long-distance transmission fibers, there is an energy transfer process between short-wavelength and long-wavelength signals. The amplitude of the energy transfer is related to the wavelength and power of the short-wavelength and long-wavelength signals. Thus, the intensity of SRS changes after adding or removing waves.

[0054] For example, such as Figure 2As shown, in an optical transport network, when one of the optical multiplexing sections fails, such as due to fiber breakage, optical module failure, or incorrect fiber removal, the original transmission of service signal light within that section is completely blocked. In downstream optical multiplexing sections, the wavelengths of the original service signal light include λ1 to λ10 and λ21 to λ30. When an upstream fiber break occurs, the service signal light from λ1 to λ10 cannot continue transmission, and the wavelength of the service signal light in the downstream optical multiplexing section changes from λ1 to λ10 and λ21 to λ30 to λ21 to λ30, i.e., wavelength drop. For the downstream optical multiplexing section, the attenuation spectrum configuration of the multiplexing / demultiplexing module remains unchanged before and after the change in service signal light. However, the particle inversion rate of the doped fiber in the optical amplifier is related to the signal wavelength, i.e., gain competition in the doped fiber. Combined with the hole-burning effect of the doped fiber, the gain spectrum of the optical amplifier changes before and after the channel change. Furthermore, the SRS effect exists in the transmission fiber, which transfers energy from short-wavelength signals to long-wavelength signals. Different channel combinations affect the intensity of SRS, i.e., the coupling process of short-wavelength and long-wavelength energy. Gain competition in optical amplifiers, aperture burning effects, and SRS effects in transmission fibers collectively cause deviations in the remaining wavelengths (λ21–30) compared to their pre-drop values. When the optical power of the service signal at each wavelength deviates before and after the drop, this deviation leads to a degradation in the OSNR of the service signal, which in turn affects the bit error rate at the receiver. Therefore, an optical multiplexing section is needed to address the performance degradation of the service signal caused by the drop.

[0055] In one approach, after a wavelength drop is detected in the optical multiplexing section, the reduced service wavelength is identified, and signal light of that wavelength (i.e., dummy light) is added to the optical multiplexing section to ensure that the wavelength of the signal light transmitted in the optical multiplexing section is the same as the wavelength of the signal light before the wavelength drop, thereby reducing the power impact caused by the wavelength drop. If a new service signal light of the dummy light wavelength is detected during the presence of dummy light, the dummy light is removed.

[0056] In this solution, because it is necessary to detect the changing service wavelength and then supplement or remove the signal light of that service wavelength, the required time is relatively long, and there will still be performance degradation during this period.

[0057] Based on this, this application provides an optical multiplexing section in which a target beam with a wavelength different from that of each service signal light is transmitted, so that the target beam and the service signal light jointly participate in the gain calculation of the optical amplifier. Since the gain of the target beam is lower than the gain of at least one service signal light, the gain of the at least one service signal light is higher than when there is no target beam, which reduces the power variation amplitude of the remaining channels. Moreover, it is not necessary to detect the wavelength of the service signal light with added or removed wavelengths. Therefore, the optical amplifier does not need to perform any additional operations after adding or removing wavelengths, so that the power variation amplitude of the remaining channels can be reduced when adding or removing wavelengths, and the response is delayed.

[0058] Figure 3 A schematic diagram of an optical multiplexing section is provided. For example... Figure 3 As shown, the optical multiplexing section includes a first multiplexing / demultiplexing module 1, an optical amplifier 2, and a second multiplexing / demultiplexing module 3. The optical amplifier 2 is located between the first multiplexing / demultiplexing module 1 and the second multiplexing / demultiplexing module 3. Both the first multiplexing / demultiplexing module 1 and the second multiplexing / demultiplexing module 3 are WDM devices or WSS. The optical amplifier 2 can be a doped fiber amplifier or a semiconductor laser amplifier, such as an erbium-doped fiber amplifier or a ytterbium-doped fiber amplifier. There can be one or more optical amplifiers 2. If there are multiple optical amplifiers 2, the types of the multiple optical amplifiers 2 can be the same or different.

[0059] The first multiplexing / demultiplexing module 1 receives the service signal light, referred to as the target service signal light. This target service signal light is input from one or more input ports of the first multiplexing / demultiplexing module 1, and after being combined into a single beam by the module, it is output to the optical amplifier 2. The optical amplifier 2 also receives the target service signal light and transmits the target beam. The wavelength of the target beam is different from that of each service signal light transmitted in the optical multiplexing section. Each service signal light has a wavelength, and multiple service signal lights can be transmitted in a single optical fiber. Each service signal light belongs to the service signal lights that the optical multiplexing section may transmit. If the optical multiplexing section is currently in a full-wavelength state, then each service signal light belongs to the service signal lights transmitted in the full-wavelength state. Assuming that the optical multiplexing section can transmit service signal lights with wavelengths from λ1 to λ10 at most, a full-wavelength state is the state of service signal lights transmitting wavelengths from λ1 to λ10. Because the target beam has a different wavelength from all the service signal lights, it can be considered out-of-band light. Optical amplifier 2 amplifies the target beam and the target service signal light, and the amplified target service signal light is output to the second multiplexing / demultiplexing module 3. The second multiplexing / demultiplexing module 3 outputs the amplified target service signal light. It should be noted that in an optical multiplexing section, the wavelengths of the out-of-band light transmitted by different optical amplifiers 2 may be the same or different, but they are collectively referred to as the target beam.

[0060] In each optical amplifier 2, the target beam has a gain. The target beam and each service signal light participate in the gain calculation of the optical amplifier 2. The gain calculation principle is shown in formula (1) and formula (2).

[0061]

[0062] In formula (1), G is the gain set by the optical amplifier, and P j The power of optical amplifier 2 is input to the service signal light j. There are a total of k service signal lights, P l G is the power of the input optical amplifier 2 for the target beam. jG represents the gain of the service signal light j in optical amplifier 2. l P represents the gain of the target beam in optical amplifier 2. Here, when the target beam has f wavelengths, P... l G l for

[0063] In each optical amplifier 2, when there is no target beam, the gain of the optical amplifier 2 is expressed as Equation (2).

[0064]

[0065] As can be seen from formulas (1) and (2), for each optical amplifier 2, the gain of the optical amplifier 2 is constant. In the presence of a target beam, in order to keep the gain of the optical amplifier 2 constant, if the target beam has a gain and the gain of the target beam is lower than the gain of at least one service signal light, then the gain of the at least one signal light is higher than when there is no target beam. In the case that the gain of the target beam is lower than the gain of each service signal light, the gain of each service signal light will be higher than when there is no target beam, thereby achieving power compensation of the service signal light and reducing the drop in power of the service signal light.

[0066] The target beam can be provided by the light providing module 4 in the optical multiplexing section. The light providing module 4 can be any type of laser, etc., or the target beam can include the ASE light generated by the optical amplifier 2, as explained below.

[0067] 1. When the target beam is provided by the light providing module 4, the optical multiplexing section has several possible structures. Three possible structures are provided below.

[0068] (1) The first structure is that the target beam is coupled to the optical amplifier 2 by the first combining and splitting module 1.

[0069] like Figure 4 As shown, the first multiplexing / splitting module 1 is connected to the optical supply module 4. The first multiplexing / splitting module 1 includes a first input port and a second input port. The first input port is used to input the target service signal light, and the second input port is used to input the target beam. The first multiplexing / splitting module 1 combines the target service signal light and the target beam into a single optical signal and outputs the single optical signal to the first optical amplifier 2. The single optical signal passes through all the optical amplifiers 2 in the optical multiplexing section and is amplified in all the optical amplifiers 2. It is output after passing through the last optical amplifier 2. The amplified target service signal light is output from the second multiplexing / splitting module 3.

[0070] Optionally, in each optical multiplexing segment, the target beam output by the optical supply module 4 is used by its own optical multiplexing segment and not by other optical multiplexing segments. The second multiplexing / splitting module 3 also has an output port for the target beam. The second multiplexing / splitting module 3 blocks the received target beam, and the target beam will not be transmitted to the next optical multiplexing segment.

[0071] Alternatively, the optical multiplexing section may also include a first wavelength division multiplexing (WDM) module 6, located between the last optical amplifier 2 and the second multiplexing / demultiplexing (DM) module 3. The last optical amplifier 2 outputs amplified target service signal light and amplified target beam light to the first WDM module 6. The first WDM module 6 separates the amplified target service signal light and the amplified target beam light according to wavelength, outputting the amplified target service signal light to the second multiplexing / demultiplexing (DM) module 3, thus blocking the amplified target beam light from further transmission in the optical multiplexing section. Alternatively, the first WDM module 6 may be located between the second multiplexing / demultiplexing (DM) module 3 and the next optical multiplexing section. In this case, the first WDM module 6 also blocks the target beam light and sends the target service signal light to the next optical multiplexing section.

[0072] In this way, by using the two methods described above, the target beam will not enter the next optical multiplexing segment.

[0073] It should be noted that in both of the above schemes, the target beam will also be transmitted in the transmission optical fiber, which will reduce the impact of the added / dropped wave on the service signal light in the transmission optical fiber, thereby improving the intensity of SRS.

[0074] (2) The second structure involves coupling the target beam to the optical amplifier 2 via the multiplexing module 5. The multiplexing module 5 can be a wavelength division multiplexer or a coupler, etc.

[0075] The optical multiplexing section includes M multiplexing modules 5, where M is less than or equal to the number of optical amplifiers 2. Each multiplexing module 5 is connected to an optical supply module 4, and each multiplexing module 5 is connected to the input of an optical amplifier 2. Different multiplexing modules 5 are connected to different optical amplifiers 2. Each multiplexing module 5 receives the target beam output from the optical supply module 4, combines the received target service signal light and the target beam into a single optical signal, and outputs this single optical signal to the connected optical amplifier 2. The optical amplifier 2 receives the single optical signal, amplifies it, and obtains the amplified target service signal light and the amplified target beam. The optical amplifier 2 then outputs the amplified target service signal light and the amplified target beam.

[0076] Optionally, such as Figure 5 and Figure 6As shown, when the optical multiplexing section includes a multiplexing module 5, the multiplexing module 5 is connected to the input terminal of the first optical amplifier 2. For example, the multiplexing module 5 is located between the first multiplexing / demultiplexing module 1 and the previous optical multiplexing section, and the first multiplexing / demultiplexing module 1 is connected to the first optical amplifier 2, indicating that the multiplexing module 5 and the first optical amplifier 2 are connected through the first multiplexing / demultiplexing module 1. As another example, the multiplexing module 5 is located between the first multiplexing / demultiplexing module 1 and the first optical amplifier 2, indicating that the multiplexing module 5 and the first optical amplifier 2 are directly connected.

[0077] Optionally, when the optical multiplexing section includes a multiplexing module 5, the target beam output from the optical supply module 4 is used by its own optical multiplexing section, and not by other optical multiplexing sections. For example... Figure 5 As shown, the second multiplexing / splitting module 3 also has an output port for the target beam. The second multiplexing / splitting module 3 will block the received target beam, and the target beam will not be transmitted to the next optical multiplexing segment.

[0078] Optionally, in each optical multiplexing segment, the target beam output by the optical supply module 4 is used by its own optical multiplexing segment and not by other optical multiplexing segments. If the optical multiplexing segment includes M multiplexing modules 5, it also includes P first wavelength division modules 6, where P is less than or equal to M. The function of the first wavelength division module 6 is to block the target beam transmitted in the optical amplifier 2. Each first wavelength division module 6 is connected to the output of a first optical amplifier. The first optical amplifier is either the optical amplifier 2 with the multiplexing module 5 connected to the input of the next optical amplifier 2, or the last optical amplifier 2. That is, the first wavelength division module 6 is located between two adjacent optical amplifiers 2, and the input of the next optical amplifier 2 is connected to the multiplexing module 5, or the first wavelength division module 6 is connected to the output of the last optical amplifier 2.

[0079] Each first wavelength division module 6 separates the received target service signal light and target beam according to wavelength, so that the target service signal light continues to transmit in the optical multiplexing section, while blocking the target beam so that the target beam no longer continues to transmit in the optical multiplexing section.

[0080] Optionally, when the first wavelength division module 6 is connected to the output of the last optical amplifier 2, the first wavelength division module 6 can be located between the last optical amplifier 2 and the second wavelength division and multiplexing module 3, or it can be located on the output path of the second wavelength division and multiplexing module 3, that is, it is located between the second wavelength division and multiplexing module 3 and the next optical multiplexing segment.

[0081] Based on the above description, the second structure can also be understood as follows: Assuming the optical multiplexing section includes N optical amplifiers 2, these N optical amplifiers 2 are divided into M groups. In each group, the input of the first optical amplifier 2 is connected to a multiplexing module 5, and the output of the last optical amplifier 2 is connected to a first wavelength division module 6. Alternatively, in the last group, the output of the last optical amplifier 2 is not connected to the first wavelength division module 6; instead, the target beam is blocked by a second multiplexing / wave division module 3. For example, as... Figure 7 As shown, N equals 4, M equals 2, and every two optical amplifiers 2 share the target beam provided by one optical supply module 4. Figure 8 As shown, N and M are equal to 3, which means that the input of each optical amplifier 2 is connected to a multiplexing module 5, and the output of each optical amplifier 2 is connected to a first demultiplexing module 6.

[0082] (3) The third structure is that the target beam is coupled to the optical amplifier 2 by the first wave combining and splitting module 1 and the wave combining module 5.

[0083] The third structure is similar to the second structure, except that in the third structure, both the first multiplexing / demultiplexing module 1 and the multiplexing module 5 are connected to the optical supply module 4. The target beam in the first group of optical amplifiers is introduced by the first multiplexing / demultiplexing module 1, while the target beams in the other groups of optical amplifiers are introduced by the multiplexing module 5. The configuration of the first demultiplexing module 6 in this structure is described in the second structure and will not be repeated here.

[0084] It should be noted that when the optical providing module 4 provides target beams to multiple modules, the optical providing module 4 can output a single beam, which is then split into multiple target beams by a power beam splitter and output to multiple modules respectively; or there can be multiple optical providing modules 4, each connected to one module, and each optical providing module 4 sends a target beam to one module. Each optical providing module 4 can be a laser. The target beams output by multiple optical providing modules 4 can be different or the same. If they are different, they can be due to different powers and / or different wavelengths.

[0085] Optionally, when the target beam is provided by the light providing module 4, the wavelength multiplexing module 5 can be a coupler or a wavelength division multiplexer, and the first wavelength division module 6 can be a wavelength division multiplexer.

[0086] 2. In the case where the target beam includes the ASE light generated by the optical amplifier 2, the ASE light includes the ASE light generated by the first optical amplifier 2, or the ASE light includes the ASE light generated by the optical amplifier 2 in the optical multiplexing section and the ASE light generated by the optical amplifier 2 in the previous optical multiplexing section. These will be explained separately below.

[0087] (1) As Figure 9 and Figure 10 As shown, the ASE light includes the ASE light generated by the first optical amplifier 2, which is transmitted throughout the optical multiplexing section.

[0088] The optical multiplexing section also includes a multiplexing module 5 and a second wavelength division multiplexing module 7. The multiplexing module 5 is connected to the second wavelength division multiplexing module 7, and the multiplexing module 5 is connected to the input terminal of the first optical amplifier 2. The second wavelength division multiplexing module 7 is connected to the output terminal of the first optical amplifier 2. The first multiplexing / demultiplexing module 1 receives the target service signal light and outputs the target service signal light to the multiplexing module 5. The multiplexing module 5 outputs the target service signal light to the first optical amplifier 2. The first optical amplifier 2 amplifies the target service signal light and outputs it to the second wavelength division multiplexing module 7. During the amplification of the target service signal light, the first optical amplifier 2 generates ASE light, which is simultaneously sent to the second wavelength division multiplexing module 7 when the amplified target service signal light is sent to the second wavelength division multiplexing module 7. The second wavelength division module 7 receives the amplified target service signal light and the ASE light. It outputs a portion of the ASE light to the multiplexing module 5. If a subsequent optical amplifier 2 is present, it outputs another portion of the ASE light and the amplified target service signal light to that amplifier. If the subsequent optical amplifier 2 is absent, it outputs the other portion of the ASE light and the amplified target service signal light to the second multiplexing / demultiplexing module 3. When the second wavelength division module 7 splits the ASE light into two parts, the splitting ratio can be set based on empirical values ​​or simulation results. For example, the two portions of the ASE light may have equal power, or, if the wavelengths of the two portions are different, their bandwidths may be the same.

[0089] Optionally, in each optical multiplexing segment, the ASE light generated by the first optical amplifier is used by its own optical multiplexing segment and will not be transmitted to the next optical multiplexing segment. In the optical multiplexing segment, the second multiplexing / demultiplexing module 3 blocks the received ASE light from the optical multiplexing segment, preventing its transmission to the next optical multiplexing segment. Alternatively, the optical multiplexing segment may also include a third multiplexing / demultiplexing module 8, which is connected to the output of the last optical amplifier 2, such as being located between the last optical amplifier 2 and the second multiplexing / demultiplexing module 3, or on the output path of the second multiplexing / demultiplexing module 3. After receiving the amplified target service signal light and ASE light, the third multiplexing / demultiplexing module 8 separates the target service signal light and ASE light, outputting the target service signal light to the second multiplexing / demultiplexing module 3 and blocking the ASE light; or, the second multiplexing / demultiplexing module 3 sends the target service signal light and ASE light to the third multiplexing / demultiplexing module 8, which blocks the ASE light and outputs the target service signal light to the next optical multiplexing segment.

[0090] (2) Figure 11As shown, in each optical multiplexing segment, when there are multiple optical amplifiers 2, the ASE light includes the ASE light generated by the optical amplifier 2 in the previous optical multiplexing segment.

[0091] The optical multiplexing section also includes a wavelength multiplexing module 5 and a wavelength splitting module 7. The wavelength multiplexing module 5 is connected to the input terminal of the i-th optical amplifier 2, and the wavelength splitting module 7 is connected to the output terminal of the i-th optical amplifier 2. i is greater than 1 and less than or equal to the number of optical amplifiers 2.

[0092] The first multiplexing / demultiplexing module 1 receives the ASE light output from the previous optical multiplexing section junction and the target service signal light (the target service signal light may not entirely come from the previous optical multiplexing section, and may also include the service signal light from the previous wave). It then outputs the target service signal light and the ASE light to the first optical amplifier 2. The first optical amplifier 2 amplifies the target service signal light and the ASE light and outputs it to the next optical amplifier 2. If the next optical amplifier 2 is the i-th optical amplifier, a second demultiplexing module 7 is provided between the multiplexing module 5 and the first optical amplifier 2. The second demultiplexing module 7 receives the target service signal light and the ASE light, outputs the target service signal light to the multiplexing module 5, and blocks the ASE light. Alternatively, the multiplexing module 5 is a wavelength division multiplexer. The multiplexing module 5 receives the target service signal light and the ASE light, but only allows the target service signal light to pass through, so that the target service signal light is output to the i-th optical amplifier 2. The i-th optical amplifier 2 amplifies the target service signal light. During this amplification process, spontaneous emission occurs, generating ASE light. The i-th optical amplifier 2 outputs both the target service signal light and the ASE light. The second wavelength division multiplexing module 7 receives the target service signal light and the ASE light, outputs a portion of the ASE light to the multiplexing module 5, and outputs the remaining portion of the ASE light and the target service signal light to the second multiplexing / demultiplexing module 3. This ensures that the optical amplifier 2 between the i-th optical amplifier 2 and the second multiplexing / demultiplexing module 3 receives both the target service signal light and the ASE light. After receiving the target service signal light and the ASE light, the second multiplexing / demultiplexing module 3 outputs them to the next optical multiplexing section. The multiplexing module 5 then re-inputs the received ASE light into the i-th optical amplifier 2 for amplification.

[0093] Figure 11 The optical multiplexing section shown in the figure includes 3 optical amplifiers 2, and the i-th optical amplifier 2 is the third optical amplifier 2 (i.e. the last optical amplifier 2).

[0094] This means that the ASE light in the optical multiplexer can be transmitted in at most two optical multiplexers.

[0095] Optionally, such as Figure 12 As shown in (a), both the multiplexing module 5 and the second demultiplexing module 7 are wavelength division multiplexers, or, as... Figure 12As shown in (b), the multiplexing module 5 includes a coupler and a filter, the second splitting module 7 is a coupler, and the filter is located between the two couplers to return the ASE light of a specified wavelength to the i-th optical amplifier 2. Alternatively, as... Figure 12 As shown in (c), the multiplexing module 5 is a coupler, and the second demultiplexing module 7 is a wavelength division multiplexer, or, as... Figure 12 As shown in (d), the multiplexing module 5 is a wavelength division multiplexer used to return the ASE light of a specified wavelength to the i-th optical amplifier. The second wavelength division module 7 is a coupler, and a portion of the ASE light output by the second wavelength division module 7 to the multiplexing module 5 has the same wavelength as another portion of the ASE light output by the second wavelength division module 7. In the above four cases, if the second wavelength division module 7 is a wavelength division multiplexer, then the wavelength of the portion of the ASE light output by the second wavelength division module 7 to the multiplexing module 5 is different from that of the other portion of the ASE light output by the second wavelength division module 7. If the second wavelength division module 7 is a coupler, then the wavelength of the portion of the ASE light output by the second wavelength division module 7 to the multiplexing module 5 is the same as that of the other portion of the ASE light output by the second wavelength division module 7. The power can be the same or different (e.g., the power ratio of the portion of the ASE light to the other portion of the ASE light is 2:3). Furthermore, when outputting this portion of the ASE light, a portion of the target service signal light is also output, which is filtered by a filter.

[0096] Optionally, ASE light of all wavelengths can be used, or ASE light of a specified wavelength can be used. The specific wavelength selected is determined based on the compensation of the service signal light. When using ASE light of a specified wavelength, a filter can be used for filtering.

[0097] It should be noted that the wave combiner module 5, the optical amplifier 2, and the second wave splitter module 7 constitute a ring resonant cavity structure, which allows ASE light of a specific wavelength to oscillate cyclically within it as the target beam.

[0098] Optionally, the filter can be a reflective filter or a transmissive filter.

[0099] Optionally, in order to control the power of the ASE light returning to the i-th optical amplifier 2, an attenuator 9 is provided between the multiplexing module 5 and the second splitting module 7, see [link to documentation]. Figure 13 Attenuator 9 attenuates the ASE light from the second wavelength division module 7 and sends the attenuated ASE light to the multiplexing module 5.

[0100] Optionally, attenuator 9 can be a fixed attenuation attenuator that attenuates the intensity of ASE light in a fixed manner, or it can be a variable optical attenuator (VOA) that attenuates the intensity of ASE light within a certain range.

[0101] In one alternative approach, the transmission optical fiber within the optical multiplexing section can also be inspected. For example, such as... Figure 14 As shown, the optical multiplexing section includes at least one set of fiber optic interface units 10. The number of sets of fiber optic interface units 10 is less than or equal to the number of transmission fibers in the optical multiplexing section. Each set of fiber optic interface units 10 includes two fiber optic interface units 10 located on both sides of a transmission fiber. The fiber optic interface unit 10 connected at the entrance of the transmission fiber inputs detection light into the transmission fiber. The detection light has a different wavelength from the target service signal light and the target beam, and receives the target service signal light. Both the target service signal light and the detection light are transmitted in the transmission fiber. When passing through the fiber optic interface unit 10 connected at the exit of the transmission fiber, the fiber optic interface unit 10 separates the target service signal light and the detection light, continuing the transmission of the target service signal light and exporting the detection light. The power of the detection light is determined, and based on the power of the detection light at the entrance and exit, information such as the transmission loss of the detection light in the transmission fiber is calculated. For example, the power difference between the detection light at the exit and the detection light at the entrance is calculated, and this power difference is determined as the transmission loss of the transmission fiber.

[0102] In this embodiment, in each optical amplifier 2 of the optical multiplexing section, the power and wavelength of the target beam are set based on empirical values ​​or obtained through simulation calculations. For example, for each optical amplifier 2, the initial power and initial wavelength of the target beam are preset. Then, the wavelength of the service signal light to be transmitted by the optical amplifier 2 is obtained. Under full-wave and various dropout conditions, the power compensation for the service signal light when transmitting the target beam with the initial power and initial wavelength is determined. Then, the initial wavelength is updated to obtain the updated wavelength. Under full-wave and various dropout conditions, the power compensation for the service signal light when transmitting the target beam with the initial power and updated wavelength is determined until the target wavelength with the best compensation is obtained. Then, the target wavelength is fixed, the initial power is updated to obtain the updated power, and under full-wave and various dropout conditions, the power compensation for the service signal light when transmitting the target beam with the updated power and target wavelength is determined until the power with the best compensation is obtained. In this way, the power of the target beam wavelength is obtained. This is only one possible method; empirical values ​​or methods that synchronously adjust the power and wavelength can also be used to obtain the power and wavelength of the target beam.

[0103] Optionally, for an optical multiplexing segment, the wavelength range of the service signal light transmitted by the optical multiplexing segment is from a first value to a second value, and the wavelength range of the target beam is from the first value - 10 nm to the first value, and / or from the second value to the second value + 10 nm. In this way, the target beam is close to the service signal light, which is more suitable for power compensation of the service signal light.

[0104] Optionally, the bandwidth of the target beam is less than or equal to 10 nm.

[0105] Optionally, the target beam can be a single-wavelength laser, belonging to a first value minus -10nm to the first value, or belonging to a second value to the second value +10nm.

[0106] Optionally, the nominal input power of each optical amplifier 2 is a third value, and the power of the target beam input into each optical amplifier 2 is the third value + 20 dBm. For example, if the nominal input power of the 50 GHz bandwidth service signal light of optical amplifier 2 is C dBm, then the power of the target beam entering the optical amplifier is C to C+20 dBm.

[0107] In this embodiment, the target beam is always transmitted in the optical multiplexing section. When no service signal light is transmitted in the optical multiplexing section, the target beam is transmitted in the optical multiplexing section. After the optical amplifier 2 recognizes the target beam input, it remains in the on state, and the doped fiber in the optical amplifier 2 maintains the upper energy level particle count. When the service signal light is transmitted in the optical multiplexing section, the upper energy level particle count is quickly utilized to achieve power amplification of the service signal light. This shortens the response time of the optical amplifier 2 when switching from no service signal light to service signal light. Moreover, it reduces the change in power ratio after adding or removing wavelengths, thereby weakening the aperture burning effect. In addition, when the target beam is present in the transmission fiber, the wavelength of the target beam is close to that of the service signal light, which also reduces the impact of adding or removing wavelengths on the service signal light in the transmission fiber, thereby improving the SRS intensity.

[0108] This application offers numerous combinations of solutions, too many to list individually. Without violating the correct logic of the solutions, the above solutions can be combined arbitrarily. For example, in an optical multiplexing section, part of the target beam transmitted by the optical amplifiers originates from the optical supply module 4, while the target beam transmitted by the other part of the optical amplifiers is ASE light.

[0109] It should be noted that the amplified target service signal light sent to the next optical multiplexer segment in the whole text may not all be sent to one optical multiplexer segment. In the case of a downwave, the target service signal light may be sent to multiple optical multiplexers.

[0110] In this embodiment of the application, an optical communication system is also provided, which includes multiple optical multiplexing segments as described above. The multiple optical multiplexing segments are connected in series and located between the transmitting end and the receiving end, providing data transmission services for the transmitting end and the receiving end.

[0111] This application embodiment also provides an optical amplifier 2 located in an optical multiplexing section. The optical amplifier 2 receives a target service signal light and a target beam, amplifies the target service signal light and the target beam, and outputs the amplified signal light and the target beam. The target beam has a different wavelength than each service signal light transmitted in the optical multiplexing section. The target beam has a gain in the optical amplifier 2, and the gain is lower than the gain of at least one service signal light transmitted in the optical multiplexing section in the optical amplifier 2, so that the at least one service signal light is not affected by the addition or subtraction of wavelengths when it is transmitted in the optical amplifier 2.

[0112] The description of the target beam and other optical amplifier 2 is provided above and will not be repeated here.

[0113] In this application, the terms "first" and "second," etc., are used to distinguish identical or similar items that have substantially the same function and purpose. It should be understood that there is no logical or temporal dependency between "first" and "second," nor does it limit the quantity or execution order. It should also be understood that although the following description uses the terms "first" and "second," etc., to describe various elements, these elements should not be limited by the terms. These terms are merely used to distinguish one element from another. For example, without departing from the scope of various examples, a first wave-splitting module can be referred to as a second wave-splitting module, and similarly, a second wave-splitting module can be referred to as a first wave-splitting module. Both the first and second wave-splitting modules can be wave-splitting modules, and in some cases, they can be separate and different wave-splitting modules.

[0114] In this application, the term "at least one" means one or more, and the term "multiple" means two or more.

[0115] The above description is merely an exemplary embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and such modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An optical multiplexer segment, characterized in that, It includes a first multiplexing / splitting module (1), an optical amplifier (2), and a second multiplexing / splitting module (3); The first multiplexing / splitting module (1) is used to output the target service signal light; The optical amplifier (2) is used to amplify and output the target service signal light and the target beam, wherein the wavelength of the target beam is different from that of each service signal light transmitted by the optical multiplexing section, the target beam has a gain in the optical amplifier (2), and the gain is lower than the gain of at least one service signal light transmitted by the optical multiplexing section in the optical amplifier (2). The second combining and splitting module (3) is used to output the amplified target service signal light.

2. The optical multiplexing section according to claim 1, characterized in that, The optical multiplexing section also includes an optical supply module (4); The light-providing module (4) is used to output the target beam into the light amplifier (2).

3. The optical multiplexing section according to claim 2, characterized in that, The first wave combining and splitting module (1) is connected to the optical providing module (4); The first combining and splitting module (1) is also used to receive the target beam from the optical providing module (4), and combine the target service signal light and the target beam into a single optical signal for output.

4. The optical multiplexing section according to claim 2, characterized in that, The optical multiplexing section also includes M multiplexing modules (5), where M is less than or equal to the number of optical amplifiers (2); The M multiplexing modules (5) are connected to the optical providing module (4), and each multiplexing module (5) is connected to the input terminal of an optical amplifier (2); Each beam combiner module (5) is used to receive the target beam from the optical providing module (4), combine the received target service signal light and the target beam into a single optical signal, and output the single optical signal to the connected optical amplifier (2).

5. The optical multiplexing section according to claim 4, characterized in that, M equals 1, and the wave combiner module (5) is connected to the input terminal of the first optical amplifier (2).

6. The optical multiplexing section according to claim 4 or 5, characterized in that, The optical multiplexing section also includes P first wavelength division modules (6), where P is less than or equal to M; Each first wavelength division module (6) is connected to the output of the first optical amplifier. The first optical amplifier is the optical amplifier (2) whose input is connected to the wavelength division module (5) or the last optical amplifier (2). Each first wavelength division module (6) is used to block the received target beam and output the received amplified target service signal light.

7. The optical multiplexing section according to any one of claims 3 to 5, characterized in that, The second beam combining and splitting module (3) is also used to block the received target beam.

8. The optical multiplexing section according to claim 1, characterized in that, The target beam includes amplified spontaneous emission (ASE) light generated by the optical amplifier (2).

9. The optical multiplexing section according to claim 8, characterized in that, There are multiple optical amplifiers (2), and the ASE light includes the ASE light generated by the first optical amplifier (2) among the multiple optical amplifiers (2).

10. The optical multiplexing section according to claim 9, characterized in that, The optical multiplexing section also includes a wavelength multiplexing module (5) and a wavelength splitting module (7). The wavelength multiplexing module (5) is connected to the wavelength splitting module (7) and is connected to the input terminal of the first optical amplifier (2). The wavelength splitting module (7) is connected to the output terminal of the first optical amplifier (2). The multiplexing module (5) is used to receive the target service signal light from the first multiplexing and demultiplexing module (1) and output the target service signal light to the first optical amplifier (2); The second wavelength division module (7) is used to receive the ASE light and the amplified target service signal light output by the first optical amplifier (2), and output a portion of the received ASE light to the multiplexing module (5), and output another portion of the ASE light and the amplified target service signal light to the second multiplexing and wavelength division module (3). The beam combiner module (5) is also used to output the received ASE light to the first optical amplifier (2).

11. The optical multiplexing section according to claim 10, characterized in that, The optical multiplexer also includes a third wavelength division module (8), which is connected to the output of the last optical amplifier (2); The third wavelength division module (8) is used to block the received ASE light and output the received target service signal light; or; The second combining and splitting module (3) is also used to block the received ASE light.

12. The optical multiplexing section according to claim 8, characterized in that, The optical amplifier (2) is multiple, and the target beam also includes the ASE light generated by the optical amplifier in the previous optical multiplexing section of the optical multiplexing section.

13. The optical multiplexing section according to claim 12, characterized in that, The optical multiplexing section also includes a wavelength combination module (5) and a second wavelength division module (7). The wavelength combination module (5) is connected to the input terminal of the i-th optical amplifier (2) in the optical multiplexing section, and the second wavelength division module (7) is connected to the output terminal of the i-th optical amplifier (2). i is greater than 1 and less than or equal to the number of optical amplifiers (2). The first multiplexing / demultiplexing module (1) is also used to receive and output the ASE light output by the previous optical multiplexing segment; The beam combiner module (5) is used to receive the amplified target service signal light and output the received target service signal light to the i-th optical amplifier (2); The second wavelength division module (7) is used to receive the ASE light and the amplified target service signal light output by the i-th optical amplifier (2), output a portion of the received ASE light to the multiplexing module (5), and output another portion of the received ASE light and the amplified target service signal light to the second multiplexing and wavelength division module (3). The beam combiner module (5) is also used to output the received ASE light to the i-th optical amplifier (2); The second multiplexing / demultiplexing module (3) is also used to output the received ASE light and the amplified target service signal light to the next optical multiplexing section.

14. The optical multiplexing section according to claim 10 or 13, characterized in that, The optical multiplexing section also includes an attenuator (9), which is located between the multiplexing module (5) and the second wavelength division module (7); The attenuator (9) is used to attenuate the received ASE light.

15. The optical multiplexing section according to any one of claims 10, 13, and 14, characterized in that, Both the multiplexing module (5) and the second demultiplexing module (7) are wavelength division multiplexers; or, The multiplexing module (5) includes a coupler and a filter, and the second demultiplexing module (7) is a coupler; or, The multiplexing module (5) is a coupler, and the second demultiplexing module (7) includes a coupler and a filter; or, The wavelength multiplexing module (5) is a coupler, and the second wavelength demultiplexing module (7) is a wavelength division multiplexer; or, The wavelength division multiplexing module (5) is a wavelength division multiplexer, and the second wavelength division multiplexing module (7) is a coupler.

16. The optical multiplexing section according to any one of claims 1 to 15, characterized in that, The wavelength range of each service signal light is from a first value to a second value, and the wavelength of the target beam is from the first value minus 10nm to the first value, and / or from the second value to the second value plus 10nm.

17. The optical multiplexing section according to any one of claims 1 to 16, characterized in that, The nominal input power of each optical amplifier (2) is the third value, and the power of the target beam input to each optical amplifier (2) is the third value plus 20 dBm.

18. The optical multiplexing section according to any one of claims 1 to 17, characterized in that, The optical multiplexing structure further includes at least one set of optical fiber interface units (10), each set of optical fiber interface units (10) being located on both sides of the transmission optical fiber in the optical multiplexing segment; Each fiber optic interface unit (10) is used to detect the performance of the connected transmission fiber.

19. An optical communication system, characterized in that, Includes multiple optical multiplexing segments as described in any one of claims 1 to 18; Multiple optical multiplex segments are connected in series.

20. An optical amplifier (2), characterized in that, The optical amplifier (2) is applied to the optical multiplexing section; The optical amplifier (2) is used for: Receive the target service signal light and the target beam; The target service signal light and the target beam are amplified and output, wherein the wavelength of the target beam is different from that of each service signal light transmitted by the optical multiplexing section, the target beam has a gain in the optical amplifier (2), and the gain is lower than the gain of at least one service signal light transmitted by the optical multiplexing section in the optical amplifier (2).

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