Optical fiber dispersion compensation adaptive amplification method and optical fiber dispersion compensation adaptive amplification apparatus

Abstract

This disclosure relates to the optical communication technology, and more particularly to an optical fiber dispersion compensation adaptive amplification method and apparatus thereof, the method comprising: obtaining a dispersion compensation value of a dispersion compensation module; redistributing the total gain of the dispersion compensation module to a plurality of optical fiber amplifiers based on the dispersion compensation value; calculating a first expected attenuation value for each variable optical attenuator installed in each optical fiber amplifier based on the redistributed gain of each optical fiber amplifier, simultaneously calculating the attenuation compensation amount for each variable optical attenuator based on the dispersion compensation value; calculating a second expected attenuation value based on the first expected attenuation value and the attenuation compensation amount; calculating an actual attenuation value based on the detected power of the first input terminal and the detected power of the first output terminal of the variable optical attenuator; and comparing the actual attenuation value with the second expected attenuation value, stopping the adjustment of the variable optical attenuator if they match, and continuing the adjustment if they do not match.

Description

Cross-reference to related applications

[0001] This application claims priority to a patent application filed with the China Patent Office on February 20, 2024, with application number 202410189515.4 and invention title "A Method and Device for Fiber Dispersion Compensation Adaptive Amplification".

Technical Field

[0002] This disclosure relates to the field of optical communication technologies, and particularly to a method for fiber dispersion compensation adaptive amplification and a device for fiber dispersion compensation adaptive amplification.

Background Art

[0003] Currently, dispersion compensation modules are mainly divided into fixed dispersion compensation modules and variable dispersion compensation modules. Both are used to solve the problem that, in a high-speed, high-bandwidth, long-distance communication system, due to the difference in refractive index, different propagation speeds occur in different transmission wavelength bands, the dispersion value of the optical fiber accumulates, the pulse width of the signal spreads, and a serious inter-symbol interference problem is caused. When adopting a fixed dispersion compensation module, only fixed dispersion can be solved. When adopting a variable dispersion module, different dispersion values can be solved, but the change in dispersion compensation of the transmission system cannot be reflected in real time, there is a delay in dispersion compensation, and in serious cases, a dispersion compensation error occurs. Also, when introducing a dispersion compensation module, the signal-to-noise ratio of the original transmission system deteriorates, and the noise figure also deteriorates.

[0004] Currently, the problems when adopting a variable dispersion module are that the variable dispersion compensation module cannot reflect the dispersion change of the transmission system in real time, and when introducing the variable dispersion compensation module, the gain flatness and noise figure of the optical transmission system deteriorate.

[0005] In view of this, overcoming the defects existing in this prior art is an issue that urgently needs to be solved in this technical field.

Summary of the Invention

[0006] The technical problems that this disclosure aims to solve are the inability of variable dispersion compensation modules to reflect changes in the dispersion of a transmission system in real time, and the deterioration of the gain flatness and noise figure of an optical transmission system when a variable dispersion compensation module is introduced.

[0007] This disclosure employs the following technical solutions.

[0008] In a first embodiment, the Disclosure provides an optical fiber dispersion compensation adaptive amplification method. The method is Obtaining the variance compensation value of the variance compensation module, Based on the aforementioned dispersion compensation value, the total gain of the dispersion compensation module is redistributed to a plurality of optical fiber amplifiers. Based on the redistribution gain of each optical fiber amplifier, a first expected attenuation value is calculated for each variable optical attenuator installed within each optical fiber amplifier. Simultaneously, the attenuation compensation amount for each variable optical attenuator is calculated based on the dispersion compensation value. A second expected attenuation value is then calculated based on the first expected attenuation value and the attenuation compensation amount. The actual attenuation value is calculated based on the detected power at the first input terminal and the detected power at the first output terminal of the variable optical attenuator. This includes comparing the actual attenuation value with the second expected attenuation value, stopping the adjustment of the variable optical attenuator if they match, and continuing the adjustment of the actual attenuation value of the variable optical attenuator if they do not match.

[0009] Preferably, when the number of optical fiber amplifiers is two, the optical fiber amplifiers include a first optical fiber amplifier and a second optical fiber amplifier. Here, the redistribution gain of the first optical fiber amplifier is the first gain, and the redistribution gain of the second optical fiber amplifier is the second gain. Redistributing the total gain of the dispersion compensation module to multiple optical fiber amplifiers based on the aforementioned dispersion compensation value means, specifically, Based on the variance compensation threshold DCM_Thr, the interval to which the variance compensation value belongs is determined. If the variance compensation value is less than or equal to DCM_Thr, the variance compensation value is located in the first interval. If the variance compensation value is greater than DCM_Thr, the variance compensation value is located in the second interval. When the gain slope of the dispersion compensation module is set to 0 and the dispersion compensation value is in the first interval, the first gain of the first optical fiber amplifier is the first threshold gain, and the second gain of the second optical fiber amplifier is the second threshold gain. If the variance compensation value is in the second interval, the first threshold gain and the second threshold gain are updated.

[0010] Preferably, if the gain slope of the dispersion compensation module is not set to 0, the distribution value of the first gain and the second gain is, specifically, When the dispersion compensation value is located in the first interval, the first gain of the first optical fiber amplifier is the third threshold gain, and the second gain of the second optical fiber amplifier is the fourth threshold gain. The third threshold gain and the fourth threshold gain are updated if the variance compensation value falls within the second interval.

[0011] Preferably, feedback closed-loop control is performed on the detected power at the second input terminal and the detected power at the second output terminal of the first optical fiber amplifier. A feedback closed-loop control is performed on the detected power at the third input terminal and the detected power at the third output terminal of the second optical fiber amplifier.

[0012] Preferably, the first expected attenuation value of the variable optical attenuator within each optical fiber amplifier is calculated based on the redistribution gain of each optical fiber amplifier, specifically, The aforementioned variance compensation value is a variable value, and based on the variance compensation threshold DCM_Thr, the variance compensation value is divided into a first interval and a second interval. If the variance compensation value is less than or equal to DCM_Thr, the variance compensation value is located in the first interval, and if the variance compensation value is greater than DCM_Thr, the variance compensation value is located in the second interval. When the aforementioned variance compensation value lies within the first interval, the first expected attenuation value is the first set attenuation value. When the aforementioned variance compensation value lies within the second interval, the first expected attenuation value is the second set attenuation value.

[0013] Preferably, the first expected attenuation value is a variable value, and the first expected attenuation value is divided into a first interval and a second interval based on the attenuation threshold Voa_att_thr, and if the first expected attenuation value is less than or equal to Voa_att_thr, the first expected attenuation value is located in the first interval, and if the first expected attenuation value is greater than Voa_att_thr, the first expected attenuation value is located in the second interval. If the number of optical attenuators is two, the optical attenuators include a first optical attenuator and a second optical attenuator. The first optical attenuator is located in the first optical fiber amplifier, and the second optical attenuator is located in the second optical fiber amplifier. If the first expected attenuation value is located within the first interval, the first set attenuation value of the first optical attenuator is updated, and the second set attenuation value of the second optical attenuator is updated. If the first expected attenuation value falls within the second interval, the first set attenuation value of the first optical attenuator is updated, and the second set attenuation value of the second optical attenuator is updated.

[0014] Preferably, the first expected attenuation values ​​of the first and second optical attenuators are adjusted based on the difference Δ between the first expected attenuation values ​​of the first and second optical attenuators. Specifically, If △ is between [0dB:0.3dB], the first set attenuation value is updated to the first actual attenuation value, and the second set attenuation value is updated to the second actual attenuation value. If △ is between [0.4dB:0.6dB], the first set attenuation value is updated to the third actual attenuation value, and the second set attenuation value is updated to the fourth actual attenuation value.

[0015] Preferably, if the actual attenuation value and the second expected attenuation value do not match, the DAC value of the variable optical attenuator is adjusted to make the actual attenuation value and the second expected attenuation value match.

[0016] In a second aspect, the Disclosure provides an optical fiber dispersion-compensated adaptive amplification apparatus applicable to the optical fiber dispersion-compensated adaptive amplification method described in the first aspect, the apparatus comprising a dispersion compensation module, a plurality of optical fiber amplifiers, and a control unit. The control unit is connected to the dispersion compensation module and is used to acquire the dispersion compensation value. The optical fiber amplifier includes a variable optical attenuator. The control unit is connected to the variable optical attenuator. The control unit is used to set the gain of the optical fiber amplifier and to adjust the attenuation value of the variable optical attenuator. The aforementioned multiple optical fiber amplifiers are cascaded. The dispersion compensation module is located between two optical fiber amplifiers. The input terminal of the dispersion compensation module is connected to the preceding optical fiber amplifier. The output terminal of the dispersion compensation module is connected to the subsequent optical fiber amplifier.

[0017] Preferably, the optical fiber amplifier further includes an erbium-doped fiber and a pump light source. The control unit is further connected to the control terminal of the pump light source and drives the pump light source based on the distributed gain. The output terminal of the pump light source is connected to the erbium-doped fiber. The erbium-doped fiber is connected to the variable optical attenuator.

[0018] The beneficial effects of this disclosure are as follows: Firstly, it solves the problem that conventional control methods cannot adaptively track the dispersion compensation value of the dispersion compensation module by rationally distributing the gain of multiple optical fiber amplifiers in real time based on the dispersion compensation value of the dispersion compensation module, which is monitored in real time.

[0019] Second, based on the dispersion compensation value of the dispersion compensation module monitored in real time, the first expected attenuation value of the variable optical attenuators of multiple optical fiber amplifiers is dynamically set in real time to adjust the gain flatness of the transmission system in real time. After completing the dispersion compensation, the gain flatness of the transmission system can be optimized.

[0020] Third, in a preferred embodiment, in addition to dynamically setting the first expected attenuation value of multiple variable optical attenuators in real time based on the dispersion compensation value of the dispersion compensation module monitored in real time, according to control needs, based on the range where the difference of the first expected attenuation values of multiple variable optical attenuators is located, the first expected attenuation values of two variable optical attenuators are redistributed, and the noise figure performance of the entire transmission system can be optimized.

[0021] To more clearly explain the technical solutions of the embodiments of the present disclosure, the drawings necessary for use in the embodiments of the present disclosure are briefly introduced below. Obviously, the drawings described below are only a part of the embodiments of the present disclosure, and those skilled in the art can obtain other drawings based on these drawings without creative labor.

Brief Description of the Drawings

[0022] [Figure 1] It is a flowchart of the optical fiber dispersion compensation adaptive amplification method provided by the embodiments of the present disclosure. [Figure 2] It is a diagram showing experimental data when the gain slope of the optical fiber dispersion compensation adaptive amplification method provided by the embodiments of the present disclosure is 0. [Figure 3] It is a diagram showing the system of the optical fiber amplifier of the optical fiber dispersion compensation adaptive amplification device provided by the embodiments of the present disclosure. [Figure 4] It is a diagram showing the feedback control system of the optical fiber dispersion compensation adaptive amplification device provided by the embodiments of the present disclosure.

Modes for Carrying out the Invention

[0023] To further clarify the purpose, technical solutions, and advantages of this disclosure, the disclosure will be described in more detail below with reference to the drawings and examples. The specific examples described herein are for illustrative purposes only and should not be understood as limiting the disclosure.

[0024] In the description of this disclosure, the orientations or positional relationships indicated by terms such as “inside,” “outside,” “vertical,” “horizontal,” “up,” “down,” “top,” and “bottom” are based on the orientations or positional relationships shown in the drawings and are merely for the purpose of facilitating the description of this disclosure. They do not require that this disclosure be constructed and operated in a particular orientation, and should therefore not be understood as a limitation on this disclosure.

[0025] In this disclosure, terms such as “First,” “Second,” etc., are used solely for illustrative purposes and should not be understood as indicating or implying relative importance or implicitly specifying the number of technical features being described. Therefore, features limited by “First,” “Second,” etc., may explicitly or implicitly include one or more such features. In this description, unless otherwise stated, “multiple” means two or more.

[0026] In this disclosure, unless otherwise explicitly provided and limited, the term “connection” should be understood broadly, for example, “connection” may be a fixed connection, a detachable connection, an integral connection, a direct connection, or an indirect connection via an intermediate medium. The term “coupling” may also refer to an electrical connection method that enables signal transmission.

[0027] Furthermore, the technical features of each embodiment of this disclosure described below can be combined with each other, insofar as they do not conflict with each other.

[0028] Example 1:

[0029] Example 1 of the present disclosure provides an optical fiber dispersion compensation adaptive amplification method, which, as shown in Figure 1, includes the following steps.

[0030] In Step 1, obtain the variance compensation value of the variance compensation module.

[0031] In one embodiment, the dispersion compensation value may be acquired by a control unit, terminal, or server. The input optical power of the input light input to the dispersion compensation module via the input photodetector is acquired, the output optical power of the output light output by the dispersion compensation module via the output photodetector is acquired, and further mathematical calculations are performed on the input optical power and output optical power to derive the dispersion compensation value. Specific implementation steps include data acquisition, i.e., measuring the input optical power and output optical power using the input photodetector and output photodetector respectively; comparison of measured values, i.e., comparing the ratio of the input optical power and output optical power after acquiring them; mathematical modeling, i.e., constructing a mathematical model that describes the relationship between dispersion and optical power based on the measurement results of the input optical power and output optical power; error analysis, i.e., analyzing the uncertainty or error range of the measurement results; and application of results, i.e., performing further adjustments or optimizations based on the calculated dispersion compensation value to ensure that the system performance meets the requirements.

[0032] In step 2, the total gain of the dispersion compensation module is redistributed to multiple optical fiber amplifiers based on the dispersion compensation value. Here, the magnitude of the total gain of the dispersion compensation module can be set by the user.

[0033] In step 3, based on the redistribution gain of each optical fiber amplifier, a first expected attenuation value for each variable optical attenuator installed in each optical fiber amplifier is calculated, the attenuation compensation amount for each variable optical attenuator is calculated based on the dispersion compensation value, and a second expected attenuation value is calculated based on the first expected attenuation value and the attenuation compensation amount.

[0034] In one embodiment, the first expected attenuation value may be Voa_att_exp1. Specifically, Voa_att_exp1 = Gain_max - Gain_set, where Gain_max is the maximum gain of the dispersion compensation module and Gain_set is the currently set gain value.

[0035] In one embodiment, the attenuation compensation amount may be Voa_comp. Specifically, Voa_comp = F(Gain_set, Input_pwr, Temp). Here, Gain_set is the currently set gain, Input_pwr is the current input optical power, and Temp is the current housing temperature of the optical fiber amplifier. Here, Gain_set corresponds to the range of the dispersion compensation value, and if the dispersion compensation value is in a different range, it corresponds to a different actually set gain value Gain_set.

[0036] In one embodiment, the second expected decay value may be Voa_att_exp1. Specifically, Voa_att_exp1 = Voa_att_exp1 + Voa_comp.

[0037] In step 4, the actual attenuation value is calculated based on the detected power at the first input terminal and the detected power at the first output terminal of the variable optical attenuator.

[0038] In one embodiment, the actual attenuation value may be Voa_att_actual. Specifically, Voa_att_actual = Output_pwr1 - Input_pwr1, where Output_pwr1 is the detected power at the first output terminal and Input_pwr1 is the detected power at the first input terminal.

[0039] In step 5, the actual attenuation value is compared with the second expected attenuation value. If they match, the adjustment of the variable optical attenuator is stopped; otherwise, the adjustment of the actual attenuation value of the variable optical attenuator is continued. Here, the specific target of the adjustment of the variable optical attenuator is the numerical value of the Digital-to-Analog Converter (DAC). If the actual attenuation value and the second expected attenuation value do not match, the DAC value of the variable optical attenuator is adjusted to make the actual attenuation value and the second expected attenuation value match.

[0040] Specifically, the actual attenuation value is compared with the second expected attenuation value. If they match, the adjustment of the variable optical attenuator is stopped; otherwise, the adjustment of the actual attenuation value of the variable optical attenuator is continued. If the actual attenuation value and the second expected attenuation value do not match, the adjustment of the actual attenuation value of the variable optical attenuator is continued, and the adjustment is stopped when the analog control voltage of the variable optical attenuator reaches either the maximum or minimum voltage value. If the actual attenuation value and the second expected attenuation value match, it indicates that the adjustment of the variable optical attenuator is complete, and there is no need to perform adjustment again within a certain monitoring period.

[0041] Specifically, the actual attenuation value is calculated based on the detected power at the first input terminal and the detected power at the first output terminal of the variable optical attenuator. Here, closed-loop control is performed on the first input terminal and the first output terminal of the variable optical attenuator to lock the calculated actual attenuation value. By locking the actual attenuation value, the system can adjust the actual attenuation value in real time to adapt to changes in the signal. This ensures that the signal is always in an optimal transmission state, reduces signal distortion and fluctuations, improves signal quality and stability, and optimizes the performance of the entire communication system. At the same time, locking the actual attenuation value also contributes to the system's compatibility with various transmission modes and protocols, enables dynamic adjustment, and prevents potential signal problems and failures.

[0042] Unlike the prior art, this embodiment has at least the following effects.

[0043] Firstly, by rationally distributing the gain of multiple optical fiber amplifiers in real time based on the dispersion compensation value of a dispersion compensation module that is monitored in real time, it is possible to solve the problem that conventional control methods cannot adaptively track the dispersion compensation value of the dispersion compensation module.

[0044] Secondly, based on the dispersion compensation value of the dispersion compensation module, which is monitored in real time, the first expected attenuation value of the variable optical attenuators of multiple optical fiber amplifiers can be dynamically set in real time, thereby adjusting the gain flatness of the transmission system in real time, completing dispersion compensation, and optimizing the gain flatness of the transmission system.

[0045] Thirdly, in a preferred embodiment, in addition to dynamically setting the first expected attenuation values ​​of multiple variable optical attenuators in real time based on the dispersion compensation values ​​of a dispersion compensation module monitored in real time, the noise figure performance of the entire transmission system can be optimized by further redistributing the first expected attenuation values ​​of two variable optical attenuators based on the range in which the difference between the first expected attenuation values ​​of the multiple variable optical attenuators lies, according to control needs.

[0046] To fully describe the solution provided in this disclosure, the details of the above method will be further explained below.

[0047] In this embodiment, F in each formula can represent the function F(x,y)=x+y, and G can represent the function G(x,y)=xy. Here, the numbers of parameters x and y can be set as needed, but in actual application scenarios, the function may be fine-tuned as required.

[0048] In step 2, the total gain of the dispersion compensation module is redistributed to multiple optical fiber amplifiers based on the dispersion compensation value. Here, the total gain specifically includes the following: In one embodiment, when the number of optical fiber amplifiers is two, the optical fiber amplifiers include a first optical fiber amplifier and a second optical fiber amplifier. A first gain is calculated based on the detection power of the second input terminal and the detection power of the second output terminal of the first optical fiber amplifier, and a second gain is calculated based on the detection power of the third input terminal and the detection power of the third output terminal of the second optical fiber amplifier. Here, the total gain is the sum of the first gain and the second gain.

[0049] The gain slope is used to describe the frequency-dependent change characteristics of the gain. When the gain slope Tilt_set = 0, the gain is constant or changes at zero across the entire operating frequency band, which helps ensure the flatness and consistency of the signal.

[0050] When the number of optical fiber amplifiers is two, the optical fiber amplifiers include a first optical fiber amplifier and a second optical fiber amplifier. Here, the redistribution gain of the first optical fiber amplifier is the first gain, and the redistribution gain of the second optical fiber amplifier is the second gain.

[0051] Redistributing the total gain of the dispersion compensation module to multiple optical fiber amplifiers based on the aforementioned dispersion compensation value means, specifically, The method includes determining the interval to which the variance compensation value belongs based on the variance compensation threshold DCM_Thr, and determining that if the variance compensation value is less than or equal to DCM_Thr, the variance compensation value is located in the first interval, and if the variance compensation value is greater than DCM_Thr, the variance compensation value is located in the second interval.

[0052] When the gain slope of the dispersion compensation module is set to 0, if the dispersion compensation value is in the first interval, the dispersion compensation value for the first interval is the first dispersion compensation value. Based on the expected gain set in the dispersion compensation module, the first dispersion compensation value, and the set gain slope, the first gain of the first optical fiber amplifier is obtained. Based on the dispersion compensation threshold and the set gain slope, the second gain of the second optical fiber amplifier is obtained. If the dispersion compensation value is in the second interval, the first gain of the first optical fiber amplifier is obtained based on the expected gain set in the dispersion compensation module and the set gain slope. Based on the dispersion compensation threshold and the set gain slope, the second gain of the second optical fiber amplifier is obtained.

[0053] In one embodiment, the gain slope set in the dispersion compensation module may be Tilt_set. When Tilt_set=0 and the dispersion compensation value is in the first interval, the first gain of the first optical fiber amplifier is Gain1_set, where Gain1_set=F(Gain_set,DCM_Range1,Tilt_set). The second gain of the second optical fiber amplifier is Gain2_set, where Gain2_set=G(DCM_Thr,Tilt_set).

[0054] Here, Gain_set represents the set expected gain, DCM_Range1 represents the current variance compensation value of the variance compensation module, and Tilt_set represents the set gain slope.

[0055] When the aforementioned dispersion compensation value is in the second interval, the first gain of the first optical fiber amplifier is Gain3_set, where Gain3_set = F(Gain_set,Tilt_set). The distribution of the second gain of the second optical fiber amplifier is Gain4_set, where Gain4_set = G(DCM_Thr,Tilt_set).

[0056] However, in actual communication systems, situations where the gain slope is not zero can arise due to the influence of various factors. These factors include, but are not limited to, the following: Non-ideal characteristics of the system, i.e., actual communication systems are not perfectly ideal, and their components and modules have some degree of nonlinearity, inconsistency, or frequency dependence. Gain changes with frequency, which can result in a non-zero gain slope. Signal processing requirements, i.e., under certain circumstances, it may be necessary to intentionally introduce a certain degree of gain slope in order to achieve a specific signal processing function or to achieve a specific performance indicator. For example, the gain slope may be intentionally adjusted to offset a specific adverse effect of the system or to improve a specific performance of the signal. Dynamic adjustment and optimization, i.e., the performance of the communication system may change as it is operated and used. By monitoring and adjusting the gain slope, the performance of the system can be dynamically optimized, and it can be ensured that the signal quality is maintained within the expected range. Configurability and flexibility, i.e., in some applications, it may be necessary to provide some degree of configurability and flexibility so that the gain slope can be adjusted according to different requirements and scenarios.

[0057] Therefore, while the signal can be maintained stably when the gain slope is Tilt_set=0, in practical applications, situations where the gain slope is not zero may arise for the reasons mentioned above. By adjusting the gain slope, system performance can be optimized, signal quality can be improved, or specific communication requirements can be met.

[0058] If the gain slope of the dispersion compensation module is not set to 0, the distribution values ​​of the first gain and the second gain are, specifically, obtained when the dispersion compensation value is in the first interval, based on the absolute values ​​of the expected gain set in the dispersion compensation module, the first dispersion compensation value, and the calculated gain slope, to obtain the first gain of the first optical fiber amplifier. The second gain of the second optical fiber amplifier is obtained based on the absolute values ​​of the dispersion compensation threshold and the calculated gain slope. If the dispersion compensation value is in the second interval, the first gain of the first optical fiber amplifier is obtained based on the absolute values ​​of the expected gain and the gain slope set in the dispersion compensation module. The second gain of the second optical fiber amplifier is obtained based on the absolute values ​​of the dispersion compensation threshold and the calculated gain slope.

[0059] In one embodiment, if Tilt_set is not 0, the distribution value of the first gain and the second gain is, specifically, When the dispersion compensation value is located in the first interval, the first gain of the first optical fiber amplifier is Gain11_set, where Gain11_set = F(Gain_set, DCM_Range1, |Tilt_cal|). The second gain of the second optical fiber amplifier is Gain21_set, where Gain21_set = G(DCM_Thr, |Tilt_cal|).

[0060] Here, Gain_set represents the set expected gain, and DCM_Range1 represents the variance compensation value of the current variance compensation module. |Tilt_cal| represents the absolute value of the gain slope calculation, where Tilt_cal = Tilt_set * K. The K value is obtained by calibration and is related to the set total gain.

[0061] When the dispersion compensation value lies in the second interval, the first gain of the first optical fiber amplifier is Gain31_set, where Gain31_set = F(Gain_set,|Tilt_set|). The second gain of the second optical fiber amplifier is Gain41_set, where Gain41_set = G(DCM_Thr,|Tilt_cal|).

[0062] According to the above method, when the gain slope is not zero, the first and second gains can be dynamically set at different gain points, thereby optimizing the gain flatness of the transmission system.

[0063] In addition, to ensure system stability, the system equipped with the dispersion compensation module continuously monitors the input and output power of the optical fiber amplifiers and adjusts their operating status in real time. This is achieved by performing feedback closed-loop control on the detected power at the second input terminal and the second output terminal of the first optical fiber amplifier, and by performing feedback closed-loop control on the detected power at the third input terminal and the third output terminal of the second optical fiber amplifier. By continuously monitoring the input and output power, the operating status of the first and second optical fiber amplifiers can be evaluated, and necessary adjustments can be made to optimize their performance.

[0064] In optical fiber amplifiers, the gain of the optical fiber amplifier may change due to various factors such as temperature changes and aging. Therefore, the gain distribution value refers to the distribution of gain to different output ports in order to amplify and transmit multi-wavelength optical signals. Accordingly, in order to ensure the stability and reliability of the system, it is necessary to take measures to lock the gain distribution value to a specific required value. In this embodiment, after implementing feedback control for the first optical fiber amplifier and the second optical fiber amplifier, the first gain redistributed to the first optical fiber amplifier and the second gain distributed to the second optical fiber amplifier are locked, so that the amplifier can provide stable and reliable amplification performance under various environments and conditions, thereby improving the transmission quality and reliability of the optical fiber communication system.

[0065] In step 3, calculating the first expected attenuation value of the variable optical attenuator within each optical fiber amplifier based on the redistribution gain of each optical fiber amplifier specifically involves: The aforementioned variance compensation value is a variable value, and based on the variance compensation threshold DCM_Thr, the variance compensation value is divided into a first interval and a second interval, and if the variance compensation value is less than or equal to DCM_Thr, the variance compensation value is located in the first interval, and if the variance compensation value is greater than DCM_Thr, the variance compensation value is located in the second interval.

[0066] If the variance compensation value falls within the first interval, the variance compensation value for the first interval is the first variance compensation value, and the first expected attenuation value is obtained based on the expected gain set in the variance compensation module and the first variance compensation value. Here, the first expected attenuation value may be Voa1_att_set, where Voa1_att_set = F(Gain_set, DCM_Range1).

[0067] Here, DCM_Range1 represents the variance compensation value when the current variance compensation module is in the first interval.

[0068] If the variance compensation value is located in the second interval, the variance compensation value for the second interval is the second variance compensation value, and the first expected attenuation value is obtained based on the set expected gain and the second variance compensation value. Here, the second expected attenuation value may be Voa2_att_set, where Voa2_att_set = G(Gain_set, DCM_Range2), where DCM_Range2 represents the variance compensation value when the current variance compensation module is in the second interval.

[0069] Since the first expected attenuation value is a variable value, it is divided into a first interval and a second interval based on the attenuation threshold Voa_att_thr. If the first expected attenuation value is less than or equal to Voa_att_thr, it is located in the first interval; if the first expected attenuation value is greater than Voa_att_thr, it is located in the second interval. To ensure the accuracy of the first expected attenuation value, it is necessary to optimize the first expected attenuation value calculated in the previous step.

[0070] When the number of optical attenuators is two, the optical attenuators include a first optical attenuator and a second optical attenuator, the first optical attenuator being located within a first optical amplifier and the second optical attenuator being located within a second optical amplifier.

[0071] If the first expected attenuation value falls within the first interval, the attenuation value for the first interval is the first attenuation value, and a first set attenuation value for the first optical attenuator is obtained based on the first attenuation value. A second set attenuation value for the second optical attenuator is obtained based on the first attenuation value and the first expected attenuation value obtained in the previous step. If the first expected attenuation value falls within the second interval, the attenuation value for the second interval is the second attenuation value, and a first set attenuation value for the first optical attenuator is obtained based on the first attenuation value. A second set attenuation value for the second optical attenuator is obtained based on the second attenuation value and the first expected attenuation value obtained in the previous step.

[0072] In one embodiment, when the first expected attenuation value is located in the first interval, the first set attenuation value of the first optical attenuator is Voa11_att_set, where Voa11_att_set = F(Voa_att_range1). The second set attenuation value of the second optical attenuator is Voa12_att_set, where Voa12_att_set = G(Voa_att_range1,Voa1_att_set).

[0073] When the first expected attenuation value falls within the second interval, the first set attenuation value of the first optical attenuator is Voa21_att_set, where Voa21_att_set = F(Voa_att_range1). The second set attenuation value of the second optical attenuator is Voa22_att_set, where Voa22_att_set = G(Voa_att_range2,Voa2_att_set).

[0074] Here, Voa_att_range1 is the attenuation value when the optical attenuator is located in the first interval, and Voa_att_range2 is the attenuation value when the optical attenuator is located in the second interval.

[0075] To further refine the optical performance of the dispersion compensation module and achieve the requirement of gain flatness, the first expected attenuation values ​​of the first and second optical attenuators are adjusted based on the difference △ between the first expected attenuation values ​​of the first and second optical attenuators. Specifically, when △ is between [0dB:0.3dB], the first set attenuation value is updated to the first actual attenuation value. Here, the first actual attenuation value is obtained by subtracting △ from the first set attenuation value. The second set attenuation value is updated to the second actual attenuation value. Here, the second actual attenuation value is obtained by adding △ to the first set attenuation value. When △ is between [0.4dB:0.6dB], the first actual attenuation value is obtained by subtracting △ / 2 from the first set attenuation value, and the second actual attenuation value is obtained by adding △ / 2 to the first set attenuation value.

[0076] If the first set attenuation value of the first optical attenuator is Voa11_att_set and the first set attenuation value of the second optical attenuator is Voa12_att_set, and △ is between [0dB:0.3dB], then Voa11_att_set is updated to the first actual attenuation value Voa11_att_set_calc, where Voa11_att_set_calc = Voa11_att_set - △. Then Voa12_att_set is updated to the second actual attenuation value Voa12_att_set_calc, where Voa12_att_set_calc = Voa11_att_set + △. If △ is between [0.4dB:0.6dB], then Voa11_att_set is updated to Voa11_att_set_calc. Here, Voa11_att_set_calc = Voa11_att_set - △ / 2. Voa12_att_set is updated to Voa12_att_set_calc. Here, Voa12_att_set_calc = Voa11_att_set + △ / 2.

[0077] If the first set attenuation value of the first optical attenuator is Voa21_att_set and the first set attenuation value of the second optical attenuator is Voa22_att_set, and △ is between [0dB:0.3dB], then Voa21_att_set is updated to the first actual attenuation value Voa21_att_set_calc, where Voa21_att_set_calc = Voa21_att_set - △. Then Voa22_att_set is updated to the second actual attenuation value Voa22_att_set_calc, where Voa22_att_set_calc = Voa21_att_set + △. If △ is between [0.4dB:0.6dB], then Voa21_att_set is updated to Voa21_att_set_calc. Here, Voa21_att_set_calc = Voa21_att_set - △ / 2. Voa22_att_set is updated to Voa22_att_set_calc. Here, Voa22_att_set_calc = Voa21_att_set + △ / 2.

[0078] In summary, the optical fiber dispersion compensation adaptive amplification method provided in the embodiment of this disclosure, in one embodiment shown in Figure 2, acquires DCM=8dB and DCM=12dB as dispersion compensation values ​​of the dispersion compensation module when the gain slope Tilt_set=0. When the gain is set to Gain_set=13dB and Gain_set=20dB, the gain slope Tilt_calc value calculated from the actually measured optical signal wavelength data is adaptively adjusted by the attenuation value of the variable optical attenuator at different gain points so that the actual gain slope Tilt_calc satisfies the preset index requirement of ±0.5dB and maintains a certain margin. The gain flatness value Gain Flatness calculated from the actually measured data satisfies the preset index requirement of ±1dB and maintains a certain margin, achieving the effect of optimizing the gain slope and gain flatness.

[0079] Example 2:

[0080] Embodiments of the present disclosure provide an optical fiber dispersion-compensated adaptive amplification apparatus applied to the optical fiber dispersion-compensated adaptive amplification method described in Embodiment 1, based on Embodiment 1, as shown in Figure 3, the apparatus includes a dispersion compensation module, a plurality of optical fiber amplifiers, and a control unit. The control unit is connected to the dispersion compensation module. The control unit is used to obtain the dispersion compensation value. The optical fiber amplifiers include variable optical attenuators. The control unit is connected to the variable optical attenuators. The control unit is used to set the gain of the optical fiber amplifiers and to adjust the attenuation value of the variable optical attenuators. The plurality of optical fiber amplifiers are cascaded. The dispersion compensation module is located between two optical fiber amplifiers. The input terminal of the dispersion compensation module is connected to the preceding optical fiber amplifier. The output terminal of the dispersion compensation module is connected to the subsequent optical fiber amplifier.

[0081] As shown in Figure 4, the optical fiber amplifier further includes an erbium-doped fiber and a pump light source. The control unit is further connected to the control terminal of the pump light source and drives the pump light source based on the distributed gain. The output terminal of the pump light source is connected to the erbium-doped fiber. The erbium-doped fiber is connected to the variable optical attenuator.

[0082] Figure 3 shows a schematic diagram of a dispersion compensation module performing dispersion compensation on two optical fiber amplifiers in one embodiment. Dispersion compensation and gain are closely related in optical communication. Dispersion is a cause of signal distortion during transmission, and gain is a parameter used to adjust the signal strength and quality. To compensate for dispersion effects, it is usually necessary to increase the gain by a certain amount to ensure the quality and stability of the signal after transmission. In optical communication systems, dispersion widens the pulse width of the signal and causes signal distortion during transmission. To reduce this effect, a dispersion compensation module is employed to provide an inverse effect of dispersion, thereby reducing or eliminating signal distortion. However, dispersion compensation does not necessarily completely eliminate signal distortion. To further improve signal quality, it is also necessary to amplify the signal, i.e., increase the gain. Gain can be used to adjust the signal strength or amplitude, thereby compensating for signal attenuation or distortion caused by dispersion. By setting the gain value rationally, it is possible to ensure that the signal remains stable and of high quality even after undergoing dispersion compensation. Therefore, in this embodiment, by performing rational gain distribution and dispersion compensation to the optical fiber amplifier using the dispersion compensation module, it is possible to effectively ensure that the signal remains stable and of high quality even after undergoing dispersion compensation. In actual application scenarios, the number of optical fiber amplifiers can be determined according to the actual demand, and is not excessively limited in this embodiment.

[0083] The foregoing are merely preferred embodiments of the Disclosure and do not limit the Disclosure. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the Disclosure should all be included within the scope of the Disclosure's protection.

Claims

1. A method for adaptive amplification with dispersion compensation for optical fibers, Obtaining the variance compensation value of the variance compensation module, Based on the aforementioned dispersion compensation value, the total gain of the dispersion compensation module is redistributed to a plurality of optical fiber amplifiers. Based on the redistribution gain of each optical fiber amplifier, a first expected attenuation value is calculated for each variable optical attenuator installed in each optical fiber amplifier; based on the dispersion compensation value, the attenuation compensation amount for each variable optical attenuator is calculated; based on the first expected attenuation value and the attenuation compensation amount, a second expected attenuation value is calculated; and based on the second expected attenuation value, the variable optical attenuator is dynamically set. The actual attenuation value is calculated based on the detected power at the first input terminal and the detected power at the first output terminal of the variable optical attenuator. This includes comparing the actual attenuation value with the second expected attenuation value, stopping the adjustment of the variable optical attenuator if they match, and continuing the adjustment of the variable optical attenuator if they do not match. A method for adaptive amplification of optical fiber dispersion compensation, characterized by the features described above.

2. When the number of optical fiber amplifiers is two, the optical fiber amplifiers include a first optical fiber amplifier and a second optical fiber amplifier, where the redistribution gain of the first optical fiber amplifier is the first gain, and the redistribution gain of the second optical fiber amplifier is the second gain. Redistributing the total gain of the dispersion compensation module to multiple optical fiber amplifiers based on the aforementioned dispersion compensation value means, specifically, Based on the variance compensation threshold DCM_Thr, the interval to which the variance compensation value belongs is determined. If the variance compensation value is less than or equal to DCM_Thr, the variance compensation value is located in the first interval. If the variance compensation value is greater than DCM_Thr, the variance compensation value is located in the second interval. When the gain slope of the dispersion compensation module is set to 0 and the dispersion compensation value is in the first interval, the dispersion compensation value in the first interval is the first dispersion compensation value, and the first gain of the first optical fiber amplifier is obtained based on the expected gain set in the dispersion compensation module, the first dispersion compensation value, and the set gain slope, and the second gain of the second optical fiber amplifier is obtained based on the dispersion compensation threshold and the set gain slope. If the dispersion compensation value is in the second interval, the first gain of the first optical fiber amplifier is obtained based on the expected gain and the set gain slope set in the dispersion compensation module, and the second gain of the second optical fiber amplifier is obtained based on the dispersion compensation threshold and the set gain slope. The optical fiber dispersion compensation adaptive amplification method according to feature 1.

3. If the gain slope of the dispersion compensation module is not set to 0, the distribution values ​​of the first gain and the second gain are, specifically, If the dispersion compensation value is located within the first interval, the first gain of the first optical fiber amplifier is obtained based on the expected gain set in the dispersion compensation module, the first dispersion compensation value, and the absolute value of the calculated gain slope, and the second gain of the second optical fiber amplifier is obtained based on the dispersion compensation threshold and the absolute value of the calculated gain slope. When the dispersion compensation value falls within a second interval, the first gain of the first optical fiber amplifier is obtained based on the absolute values ​​of the expected gain and gain slope set in the dispersion compensation module, and the second gain of the second optical fiber amplifier is obtained based on the absolute values ​​of the dispersion compensation threshold and the calculated gain slope value. The optical fiber dispersion compensation adaptive amplification method according to feature 2.

4. Feedback closed-loop control is performed on the detected power at the second input terminal and the detected power at the second output terminal of the first optical fiber amplifier. The second optical fiber amplifier performs feedback closed-loop control on the detected power at the third input terminal and the detected power at the third output terminal. The optical fiber dispersion compensation adaptive amplification method according to feature 2.

5. The total gain is the sum of the first gain and the second gain. The optical fiber dispersion compensation adaptive amplification method according to feature 2.

6. Specifically, calculating the first expected attenuation value of the variable optical attenuator within each optical fiber amplifier based on the redistribution gain of each optical fiber amplifier means: The aforementioned variance compensation value is a variable value, and based on the variance compensation threshold DCM_Thr, the variance compensation value is divided into a first interval and a second interval. If the variance compensation value is less than or equal to DCM_Thr, the variance compensation value is located in the first interval, and if the variance compensation value is greater than DCM_Thr, the variance compensation value is located in the second interval. If the aforementioned variance compensation value falls within the first interval, the variance compensation value for the first interval is the first variance compensation value, and a first expected attenuation value is obtained based on the expected gain set in the variance compensation module and the first variance compensation value. If the aforementioned variance compensation value falls within the second interval, the variance compensation value for the second interval is the second variance compensation value, and the first expected decay value is obtained based on the set expected gain and the second variance compensation value. The optical fiber dispersion compensation adaptive amplification method according to feature 1.

7. The first expected decay value is a variable value, and the first expected decay value is divided into a first interval and a second interval based on the decay threshold Voa_att_thr. If the first expected attenuation value is less than or equal to Voa_att_thr, the first expected attenuation value is located in the first interval, and if the first expected attenuation value is greater than Voa_att_thr, the first expected attenuation value is located in the second interval. If the number of optical attenuators is two, the optical attenuators include a first optical attenuator and a second optical attenuator, the first optical attenuator being located within the first optical fiber amplifier, and the second optical attenuator being located within the second optical fiber amplifier. If the first expected attenuation value falls within the first interval, the attenuation value for the first interval is the first attenuation value, and based on the first attenuation value, the first set attenuation value of the first optical attenuator is obtained, and based on the first attenuation value and the first expected attenuation value obtained in the previous step, the second set attenuation value of the second optical attenuator is obtained. If the first expected attenuation value falls within the second interval, the attenuation value for the second interval is the second attenuation value. Based on the first attenuation value, the first set attenuation value of the first optical attenuator is obtained. Based on the second attenuation value and the first expected attenuation value obtained in the previous step, the second set attenuation value of the second optical attenuator is obtained. The optical fiber dispersion compensation adaptive amplification method according to feature 6.

8. This includes adjusting the first expected attenuation values ​​of the first optical attenuator and the second optical attenuator, respectively, based on the difference △ between the first expected attenuation values ​​of the first optical attenuator and the second optical attenuator, specifically: If the aforementioned △ is between [0 dB: 0.3 dB], the first set attenuation value is updated to the first actual attenuation value, where the first set attenuation value and △ are subtracted to obtain the first actual attenuation value. The second set attenuation value is updated to the second actual attenuation value, where the first set attenuation value and △ are added to obtain the second actual attenuation value. If the aforementioned △ is between [0.4 dB:0.6 dB], the first actual attenuation value is obtained by subtracting △ / 2 from the first set attenuation value, and the second actual attenuation value is obtained by adding △ / 2 to the first set attenuation value. The optical fiber dispersion compensation adaptive amplification method according to feature 7.

9. If the actual attenuation value and the second expected attenuation value do not match, the DAC value of the variable optical attenuator is adjusted to make the actual attenuation value and the second expected attenuation value match. The optical fiber dispersion compensation adaptive amplification method according to any one of claims 1 to 8.

10. The first expected attenuation value is obtained by subtracting the maximum gain of the dispersion compensation module from the gain value actually set at a predetermined time. The optical fiber dispersion compensation adaptive amplification method according to any one of claims 1 to 8.

11. The attenuation compensation amount is obtained based on the gain value actually set at a predetermined time, the optical power input at a predetermined time, and the housing temperature of the optical fiber amplifier at a predetermined time. The optical fiber dispersion compensation adaptive amplification method according to any one of claims 1 to 8.

12. The second expected attenuation value is obtained by adding the first expected attenuation value and the attenuation compensation amount. The optical fiber dispersion compensation adaptive amplification method according to any one of claims 1 to 8.

13. The actual attenuation value is obtained by subtracting the detected power at the first output terminal from the detected power at the first input terminal. The optical fiber dispersion compensation adaptive amplification method according to any one of claims 1 to 8.

14. An optical fiber dispersion compensation adaptive amplification apparatus, applicable to the optical fiber dispersion compensation adaptive amplification method described in any one of claims 1 to 8, comprising a dispersion compensation module, a plurality of optical fiber amplifiers, and a control unit, wherein the control unit is connected to the dispersion compensation module, and the control unit is used to acquire the dispersion compensation value. The optical fiber amplifier includes a variable optical attenuator, the control unit is connected to the variable optical attenuator, and the control unit is used to set the gain of the optical fiber amplifier and adjust the attenuation value of the variable optical attenuator. The plurality of optical fiber amplifiers are cascaded, the dispersion compensation module is located between two optical fiber amplifiers, the input terminal of the dispersion compensation module is connected to the preceding optical fiber amplifier, and the output terminal of the dispersion compensation module is connected to the subsequent optical fiber amplifier. A fiber optic dispersion compensation adaptive amplification device characterized by the following features.

15. The optical fiber amplifier further includes an erbium-doped fiber and a pump light source, and the control unit is further connected to the control terminal of the pump light source and drives the pump light source based on the distributed gain. The output terminal of the pump light source is connected to the erbium-doped fiber, and the erbium-doped fiber is connected to the variable optical attenuator. The optical fiber dispersion compensation adaptive amplification device according to feature 14.

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