Method and apparatus for adaptive amplification of optical fiber dispersion compensation

Abstract

The present invention relates to the technical field of optical communications, in particular to a method and apparatus for adaptive amplification of optical fiber dispersion compensation. The method comprises: acquiring a dispersion compensation value of a dispersion compensation module; on the basis of the dispersion compensation value, reallocating the total gain of the dispersion compensation module to a plurality of optical fiber amplifiers; on the basis of the re-allocated gain of each optical fiber amplifier, calculating a first expected attenuation value of a variable optical attenuator arranged in each optical fiber amplifier, on the basis of the dispersion compensation value, calculating the attenuation compensation amount of each variable optical attenuator, and, on the basis of the first expected attenuation value and the attenuation compensation amount, calculating a second expected attenuation value; on the basis of the detection power of a first input end and the detection power of a first output end of each variable optical attenuator, calculating an actual attenuation value; and comparing the actual attenuation value with the second expected attenuation value, if the actual attenuation value is consistent with the second expected attenuation value, stopping adjusting the variable optical attenuator, otherwise, continuing to adjust same.

Description

A method and device for adaptive amplification of optical fiber dispersion compensation

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority from the following patent applications:

[0003] (1) Submitted to the Chinese Patent Office on February 20, 2024, application number 2024101895154, titled “A method and device for adaptive amplification of optical fiber dispersion compensation”; Technical Field

[0004] The present invention relates to the technical field of optical communications, and in particular to a method and device for adaptively amplifying optical fiber dispersion compensation. Background Art

[0005] Currently, dispersion compensation modules are primarily categorized as fixed and variable. Both are designed to address the problem of varying propagation velocities in different transmission bands due to differences in refractive index in high-speed, high-bandwidth, and long-haul communication systems. This accumulation of fiber dispersion leads to pulse broadening and severe intersymbol crosstalk (ISI). Fixed dispersion compensation modules can only address fixed dispersion, while variable dispersion modules can address varying dispersion values. However, they cannot reflect dispersion compensation changes in the transmission system in real time, resulting in a lag in dispersion compensation and, in severe cases, dispersion compensation errors. Furthermore, the introduction of dispersion compensation modules can degrade the signal-to-noise ratio (SNR) and noise figure (NF) of the transmission system.

[0006] Currently, the problem with using variable dispersion compensation modules is that they cannot reflect the dispersion changes of the transmission system in real time. On the other hand, the introduction of variable dispersion compensation modules will lead to the degradation of the gain flatness and noise indicators of the optical transmission system.

[0007] In view of this, overcoming the defects of the prior art is an urgent problem to be solved in this technical field.

[0008] Application Contents

[0009] The technical problems to be solved by the present invention are that the variable dispersion compensation module cannot reflect the dispersion changes of the transmission system in real time; and the introduction of the variable dispersion compensation module will lead to the degradation of the gain flatness and noise indicators of the optical transmission system.

[0010] The present invention adopts the following technical solutions:

[0011] In a first aspect, the present invention provides a method for adaptive amplification of optical fiber dispersion compensation, comprising:

[0012] Obtaining the dispersion compensation value of the dispersion compensation module;

[0013] reallocating the total gain of the dispersion compensation module to the plurality of optical fiber amplifiers according to the dispersion compensation value;

[0014] calculating a first expected attenuation value of a variable optical attenuator disposed in each optical fiber amplifier based on the redistributed gain of each optical fiber amplifier, and calculating an attenuation compensation amount of each variable optical attenuator based on the dispersion compensation value; and calculating a second expected attenuation value based on the first expected attenuation value and the attenuation compensation amount;

[0015] Calculating an actual attenuation value according to the detection power at the first input end and the detection power at the first output end of the variable optical attenuator;

[0016] The actual attenuation value is compared with the second expected attenuation value. If they are consistent, the adjustment of the variable optical attenuator is stopped; otherwise, the actual attenuation value of the variable optical attenuator is continued to be adjusted.

[0017] Preferably, when the number of the optical fiber amplifiers is 2, the optical fiber amplifiers include a first optical fiber amplifier and a second optical fiber amplifier; wherein the gain of the first optical fiber amplifier after redistribution is the first gain, and the gain of the second optical fiber amplifier after redistribution is the second gain;

[0018] The redistributing the total gain of the dispersion compensation module to the plurality of optical fiber amplifiers according to the dispersion compensation value specifically includes:

[0019] Determining the interval to which the dispersion compensation value belongs according to the dispersion compensation threshold DCM_Thr, if the dispersion compensation value is less than or equal to DCM_Thr, the dispersion compensation value is in a first interval; if the dispersion compensation value is greater than DCM_Thr, the dispersion compensation value is in a second interval;

[0020] When the gain slope of the dispersion compensation module is set to 0, if the dispersion compensation value is in the first interval, the first gain of the first optical fiber amplifier is a first threshold gain; and the second gain of the second optical fiber amplifier is a second threshold gain;

[0021] If the dispersion compensation value is in the second interval, the first threshold gain and the second threshold gain will be updated.

[0022] Preferably, when the gain slope of the dispersion compensation module is set to not be 0, the distribution value of the first gain and the second gain specifically includes:

[0023] When the dispersion compensation value is in the first interval, the first gain of the first optical fiber amplifier is a third threshold gain; and the second gain of the second optical fiber amplifier is a fourth threshold gain;

[0024] When the dispersion compensation value is in the second interval, the third threshold gain and the fourth threshold gain will be updated.

[0025] Preferably, the detection power at the second input end and the detection power at the second output end of the first optical fiber amplifier are feedback closed-loop controlled;

[0026] The detection power at the third input end and the detection power at the third output end of the second optical fiber amplifier are controlled by feedback closed loop.

[0027] Preferably, the step of calculating the first expected attenuation value of the variable optical attenuator in each optical fiber amplifier according to the redistributed gain of each optical fiber amplifier specifically includes:

[0028] The dispersion compensation value is a variable value, and is divided into a first interval and a second interval according to a dispersion compensation threshold DCM_Thr; if the dispersion compensation value is less than or equal to DCM_Thr, the dispersion compensation value is in the first interval; if the dispersion compensation value is greater than DCM_Thr, the dispersion compensation value is in the second interval;

[0029] When the dispersion compensation value is in the first interval, the first expected attenuation value is the first set attenuation value;

[0030] When the dispersion compensation value is in the second interval, the first expected attenuation value is the second set attenuation value.

[0031] Preferably, the first expected attenuation value is a variable value, and is divided into a first interval and a second interval according to an attenuation threshold Voa_att_thr. When the first expected attenuation value is less than or equal to Voa_att_thr, the first expected attenuation value is in the first interval; when the first expected attenuation value is greater than Voa_att_thr, the first expected attenuation value is in the second interval. When the number of the 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.

[0032] When the first expected attenuation value is within a first interval, updating a first set attenuation value of the first optical attenuator; and updating a second set attenuation value of the second optical attenuator;

[0033] When the first expected attenuation value is 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.

[0034] Preferably, adjusting the first expected attenuation values ​​of the first optical attenuator and the second optical attenuator respectively according to the difference Δ between the first expected attenuation values ​​of the first optical attenuator and the second optical attenuator specifically includes:

[0035] When Δ is between [0dB:0.3dB], the first set attenuation value will be updated to the first actual attenuation value; the second set attenuation value will be updated to the second actual attenuation value;

[0036] When Δ is between [0.4dB:0.6dB], the first set attenuation value will be updated to the third actual attenuation value; the second set attenuation value will be updated to the fourth actual attenuation value.

[0037] Preferably, if the actual attenuation value is inconsistent with the second expected attenuation value, the DAC value of the variable optical attenuator is adjusted to make the actual attenuation value consistent with the second expected attenuation value.

[0038] In a second aspect, the present invention provides a device for adaptive amplification of optical fiber dispersion compensation, applicable to the method for adaptive amplification of optical fiber dispersion compensation described in the first aspect, 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 the control unit is configured to obtain the dispersion compensation value;

[0039] 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 configure the gain of the optical fiber amplifier and adjust the attenuation value of the variable optical attenuator;

[0040] The multiple fiber amplifiers are cascaded, the dispersion compensation module is located between two fiber amplifiers, the input end of the dispersion compensation module is connected to the previous fiber amplifier, and the output end of the dispersion compensation module is connected to the next fiber amplifier.

[0041] Preferably, the optical fiber amplifier further comprises an erbium-doped optical fiber and a pump source, and the control unit is further connected to a control end of the pump source to drive the pump source according to the allocated gain;

[0042] The output end of the pump source is connected to the erbium-doped optical fiber, and the erbium-doped optical fiber is connected to the variable optical attenuator.

[0043] The beneficial effects of the present invention are as follows: First, based on the dispersion compensation value of the dispersion compensation module monitored in real time, the gains of multiple optical fiber amplifiers are reasonably distributed in real time, solving the problem that traditional control methods cannot adaptively follow the dispersion compensation value of the dispersion compensation module.

[0044] Secondly, based on the real-time monitoring of the dispersion compensation value of the dispersion compensation module, the first expected attenuation value of the variable optical attenuator of multiple fiber amplifiers is dynamically configured in real time, and the gain flatness of the transmission system is adjusted in real time. On the basis of completing the dispersion compensation, the gain flatness of the transmission system is optimized.

[0045] Thirdly, in a preferred embodiment, based on the real-time monitoring of the dispersion compensation value of the dispersion compensation module, in addition to dynamically configuring the first expected attenuation values ​​of multiple variable optical attenuators in real time, the first expected attenuation values ​​of two variable optical attenuators are reallocated according to the range of the difference between the first expected attenuation values ​​of the multiple variable optical attenuators based on control needs, thereby optimizing the noise index performance of the entire transmission system. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0047] FIG1 is a flow chart of a method for adaptive amplification of optical fiber dispersion compensation provided by an embodiment of the present invention;

[0048] FIG2 is a schematic diagram of experimental data when the gain slope is 0 for a method for adaptive amplification of optical fiber dispersion compensation provided by an embodiment of the present invention;

[0049] 3 is a system diagram of an optical fiber amplifier of an optical fiber dispersion compensation adaptive amplification device provided by an embodiment of the present invention;

[0050] FIG4 is a schematic diagram of a feedback control system of an optical fiber dispersion compensation adaptive amplification device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0052] In the description of the present invention, the terms "inside", "outside", "longitudinal", "lateral", "upper", "lower", "top", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention.

[0053] The terms "first," "second," etc., used in this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified with "first," "second," etc. may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0054] In this application, unless otherwise specified or limited, the term "connection" should be understood broadly. For example, "connection" can mean fixed connection, detachable connection, or integration; it can mean direct connection or indirect connection through an intermediate medium. In addition, the term "coupling" can refer to the manner in which electrical connection is achieved for signal transmission.

[0055] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0056] Embodiment 1:

[0057] Embodiment 1 of the present invention provides a method for adaptive amplification of optical fiber dispersion compensation, as shown in FIG1 , including:

[0058] In step 1, a dispersion compensation value of a dispersion compensation module is obtained.

[0059] In one embodiment, the dispersion compensation value can be obtained by a control unit, a terminal, or a server. The input optical power of the input light input to the dispersion compensation module is obtained via an input photodetector, and the output optical power of the output light output by the dispersion compensation module is obtained via an output photodetector. Mathematical operations are then performed on the input and output optical powers to derive the dispersion compensation value. The specific implementation steps include: data acquisition, using an input photodetector and an output photodetector to measure the input and output optical powers, respectively; comparative measurement, after obtaining the input and output optical powers, comparing the ratio of the input and output optical powers; mathematical modeling, based on the measurement results of the input and output optical powers, establishing a mathematical model to describe the relationship between dispersion and optical power; error analysis, analyzing the uncertainty or error range of the measurement results; and application of the results, performing further adjustments or optimizations based on the calculated dispersion compensation value to ensure that system performance meets requirements.

[0060] In step 2, the total gain of the dispersion compensation module is redistributed to multiple optical fiber amplifiers according to the dispersion compensation value. The total gain of the dispersion compensation module can be set by the user.

[0061] In step 3, a first expected attenuation value of a variable optical attenuator located in each optical fiber amplifier is calculated based on the redistributed gain of each optical fiber amplifier, and an attenuation compensation amount of 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.

[0062] In one embodiment, the first expected attenuation value may be Voa_att_exp1. Specifically, Voa_att_exp1=Gain_max-Gain_set; wherein Gain_max is the maximum gain of the dispersion compensation module, and Gain_set is the currently actually set gain value.

[0063] In one embodiment, the attenuation compensation amount may be Voa_comp. Specifically, Voa_comp = F(Gain_set, Input_pwr, Temp); where Gain_set is the currently set gain, Input_pwr is the current input optical power, and Temp is the current case temperature of the fiber amplifier. Gain_set corresponds to a range of dispersion compensation values, and different dispersion compensation value ranges correspond to different actually set gain values, Gain_set.

[0064] In one embodiment, the second expected attenuation value may be Voa_att_exp1; specifically, Voa_att_exp1=Voa_att_exp1+Voa_comp.

[0065] In step 4, an actual attenuation value is calculated according to the detection power at the first input end and the detection power at the first output end of the variable optical attenuator.

[0066] In one embodiment, the actual attenuation value may be Voa_att_actual. Specifically, Voa_att_actual=Output_pwr1−Input_pwr1; wherein Output_pwr1 is the detection power of the first output end, and Input_pwr1 is the detection power of the first input end.

[0067] In step 5, the actual attenuation value is compared with the second expected attenuation value. If they are consistent, adjustment of the variable optical attenuator is stopped; otherwise, adjustment of the actual attenuation value of the variable optical attenuator continues. The specific object of adjustment of the variable optical attenuator is the value of the digital analog converter (DAC). If the actual attenuation value is inconsistent with the second expected attenuation value, the DAC value of the variable optical attenuator is adjusted to make the actual attenuation value consistent with the second expected attenuation value.

[0068] Specifically, the actual attenuation value is compared with the second expected attenuation value. If they are consistent, adjustment of the variable optical attenuator is stopped; otherwise, adjustment of the actual attenuation value of the variable optical attenuator continues. If the actual attenuation value is inconsistent with the second expected attenuation value, adjustment of the actual attenuation value of the variable optical attenuator continues until the analog control voltage of the variable optical attenuator reaches one of a maximum voltage value or a minimum voltage value, at which point adjustment is stopped. If the actual attenuation value is consistent with the second expected attenuation value, it indicates that the variable optical attenuator has been adjusted to the desired value and no further adjustment is required during the monitored time.

[0069] Specifically, the actual attenuation value is calculated based on the detection power at the first input and the detection power at the first output of the variable optical attenuator. Closed-loop control is then performed on the first input and the first output 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 signal changes, thereby ensuring that the signal is always in an optimal transmission state, reducing signal distortion and fluctuations, improving signal quality and stability, and optimizing the performance of the entire communication system. Furthermore, locking the actual attenuation value helps the system be compatible with multiple transmission modes and protocols, enabling dynamic adjustment and preventing potential signal problems and failures.

[0070] Different from the prior art, this embodiment has at least the following effects:

[0071] First, the gains of multiple optical fiber amplifiers are reasonably distributed in real time according to the dispersion compensation value of the dispersion compensation module monitored in real time, solving the problem that traditional control methods cannot adaptively follow the dispersion compensation value of the dispersion compensation module.

[0072] Secondly, based on the real-time monitoring of the dispersion compensation value of the dispersion compensation module, the first expected attenuation value of the variable optical attenuator of multiple fiber amplifiers is dynamically configured in real time, and the gain flatness of the transmission system is adjusted in real time. On the basis of completing the dispersion compensation, the gain flatness of the transmission system is optimized.

[0073] Thirdly, in a preferred embodiment, based on the real-time monitoring of the dispersion compensation value of the dispersion compensation module, in addition to dynamically configuring the first expected attenuation values ​​of multiple variable optical attenuators in real time, the first expected attenuation values ​​of two variable optical attenuators are reallocated according to the range of the difference between the first expected attenuation values ​​of the multiple variable optical attenuators based on control needs, thereby optimizing the noise index performance of the entire transmission system.

[0074] In order to fully illustrate the solution provided by the present invention, the details of the above method will be further described below.

[0075] In this embodiment, F appearing in each formula may represent the function F(x,y)=x+y, and G may represent the function G(x,y)=xy, where the number of parameters x and y may be set as needed. However, in actual application scenarios, the function may be fine-tuned as needed.

[0076] In step 2, the total gain of the dispersion compensation module is redistributed to the plurality of optical fiber amplifiers according to the dispersion compensation value, wherein the total gain specifically includes:

[0077] In one embodiment, when the number of the 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 at the second input end and the detection power at the second output end of the first optical fiber amplifier; a second gain is calculated based on the detection power at the third input end and the detection power at the third output end of the second optical fiber amplifier; wherein the total gain is the sum of the first gain and the second gain.

[0078] The gain slope is used to describe the characteristics of gain change with frequency. When the gain slope Tilt_set = 0, the gain remains constant or the rate of change is 0 within the entire operating frequency band, which helps to ensure the flatness and consistency of the signal.

[0079] When the number of the optical fiber amplifiers is 2, the optical fiber amplifiers include a first optical fiber amplifier and a second optical fiber amplifier; wherein the gain of the first optical fiber amplifier after redistribution is the first gain, and the gain of the second optical fiber amplifier after redistribution is the second gain;

[0080] The redistributing the total gain of the dispersion compensation module to the plurality of optical fiber amplifiers according to the dispersion compensation value specifically includes:

[0081] The interval to which the dispersion compensation value belongs is determined according to the dispersion compensation threshold DCM_Thr. If the dispersion compensation value is less than or equal to DCM_Thr, the dispersion compensation value is in the first interval. If the dispersion compensation value is greater than DCM_Thr, the dispersion compensation value is in the second interval.

[0082] When the gain slope of the dispersion compensation module is set to 0, if the dispersion compensation value is in a first range, the dispersion compensation value in the first range is the first dispersion compensation value, and a first gain of the first optical fiber amplifier is obtained according to the expected gain, the first dispersion compensation value, and the set gain slope set in the dispersion compensation module; and a second gain of the second optical fiber amplifier is obtained according to a dispersion compensation threshold and the set gain slope. If the dispersion compensation value is in a second range, the first gain of the first optical fiber amplifier is obtained according to the expected gain and the set gain slope set in the dispersion compensation module; and a second gain of the second optical fiber amplifier is obtained according to the dispersion compensation threshold and the set gain slope.

[0083] In one embodiment, the gain slope of the dispersion compensation module can be set to Tilt_set. When Tilt_set=0, if the dispersion compensation value is in the first interval, the first gain of the first optical fiber amplifier is Gain1_set; wherein Gain1_set=F(Gain_set, DCM_Range1, Tilt_set); the second gain of the second optical fiber amplifier is Gain2_set; wherein Gain2_set=G(DCM_Thr, Tilt_set).

[0084] Gain_set indicates the desired gain, DCM_Range1 indicates the dispersion compensation value of the current dispersion compensation module, and Tilt_set indicates the gain slope.

[0085] If the dispersion compensation value is in the second interval, the first gain of the first optical fiber amplifier is Gain3_set, wherein Gain3_set=F(Gain_set, Tilt_set); the second gain distribution of the second optical fiber amplifier is Gain4_set, wherein Gain4_set=G(DCM_Thr, Tilt_set).

[0086] However, in actual communication systems, the situation where the gain slope is not equal to 0 may be affected by various factors, including but not limited to: non-ideal characteristics of the system. The actual communication system is not completely ideal. The components and modules therein may have certain nonlinearities, inconsistencies or frequency dependencies, which may cause the gain to vary with frequency, resulting in a non-zero gain slope; signal processing requirements. In some cases, in order to achieve specific signal processing functions or achieve specific performance indicators, it may be necessary to deliberately introduce a certain gain slope. For example, in order to offset certain adverse effects of the system or improve the specific performance of the signal, the gain slope may be deliberately adjusted; dynamic adjustment and optimization: As the communication system is operated and used, its performance may change. By monitoring and adjusting the gain slope, the performance of the system can be dynamically optimized to ensure that the signal quality remains within the desired range; configurability and flexibility. In some applications, it may be necessary to provide a certain degree of configurability and flexibility to adjust the gain slope according to different needs and scenarios.

[0087] Therefore, although the signal remains stable when the gain slope is set to Tilt_set = 0, in actual applications, the gain slope may not be equal to 0 due to the above reasons. By adjusting the gain slope, system performance can be optimized, signal quality can be improved, or specific communication requirements can be met.

[0088] When the gain slope of the dispersion compensation module is set to non-zero, the allocation values ​​of the first gain and the second gain specifically include: when the dispersion compensation value is within a first range, obtaining the first gain of the first optical fiber amplifier according to the expected gain set in the dispersion compensation module, the first dispersion compensation value, and the absolute value of the calculated gain slope; obtaining the second gain of the second optical fiber amplifier according to the dispersion compensation threshold and the absolute value of the calculated gain slope; when the dispersion compensation value is within a second range, obtaining the first gain of the first optical fiber amplifier according to the expected gain set in the dispersion compensation module and the absolute value of the gain slope; and obtaining the second gain of the second optical fiber amplifier according to the dispersion compensation threshold and the absolute value of the calculated gain slope.

[0089] In one embodiment, when Tilt_set is not 0, the distribution values ​​of the first gain and the second gain specifically include:

[0090] When the dispersion compensation value is 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|).

[0091] Wherein, Gain_set represents the desired gain, DCM_Range1 represents the dispersion compensation value of the current dispersion compensation module, |Tilt_cal| represents the absolute value of the calculated gain slope, |Tilt_cal|=Tilt_set*K, where the K value is a calibrated value and is related to the set total gain.

[0092] When the dispersion compensation value is in the second interval, the first gain of the first optical fiber amplifier is Gain31_set, wherein Gain31_set=F(Gain_set, |Tilt_set|); the second gain of the second optical fiber amplifier is Gain41_set, wherein Gain41_set=G(DCM_Thr, |Tilt_cal|).

[0093] According to the above method, when the gain slope is not equal to 0, the first gain and the second gain are dynamically configured at different gain points, thereby optimizing the gain flatness of the transmission system.

[0094] Furthermore, to ensure that the system housing the dispersion compensation module can continuously monitor the input and output power of the fiber amplifiers and adjust their operating status in real time to ensure system stability, the detection power at the second input and second output of the first fiber amplifier is controlled by a feedback closed-loop; the detection power at the third input and third output of the second fiber amplifier is also controlled by a feedback closed-loop. By continuously monitoring the input and output power, the operating status of the first and second fiber amplifiers can be assessed and necessary adjustments can be made to optimize their performance.

[0095] In a fiber amplifier, gain allocation refers to the distribution of gain to different output ports to achieve amplification and transmission of multi-wavelength optical signals. Due to various factors, such as temperature fluctuations and aging, the gain of a fiber amplifier may vary. Therefore, to ensure system stability and reliability, measures are required to lock the gain allocation to a specific, desired value. In this embodiment, after implementing feedback control of the first and second fiber amplifiers, the first gain reallocated to the first fiber amplifier and the second gain allocated to the second fiber amplifier are locked. This ensures that the amplifiers provide stable and reliable amplification performance under various environments and conditions, thereby improving the transmission quality and reliability of the fiber-optic communication system.

[0096] In step 3, the first expected attenuation value of the variable optical attenuator located in each optical fiber amplifier is calculated based on the redistributed gain of each optical fiber amplifier, which specifically includes:

[0097] The dispersion compensation value is a variable value, and is divided into a first interval and a second interval according to the dispersion compensation threshold DCM_Thr; if the dispersion compensation value is less than or equal to DCM_Thr, the dispersion compensation value is in the first interval; if the dispersion compensation value is greater than DCM_Thr, the dispersion compensation value is in the second interval.

[0098] When the dispersion compensation value is in the first interval, the dispersion compensation value in the first interval is the first dispersion compensation value, and a first expected attenuation value is obtained according to the expected gain set in the dispersion compensation module and the first dispersion compensation value; wherein the first expected attenuation value can be Voa1_att_set; wherein Voa1_att_set=F(Gain_set, DCM_Range1).

[0099] Wherein DCM_Range1 represents the dispersion compensation value of the current dispersion compensation module in the first range.

[0100] When the dispersion compensation value is in the second interval, the dispersion compensation value in the second interval is the second dispersion compensation value, and the first expected attenuation value is obtained according to the set expected gain and the second dispersion compensation value; the second expected attenuation value can be Voa2_att_set; wherein, Voa2_att_set = G(Gain_set, DCM_Range2).

[0101] Wherein DCM_Range2 represents the dispersion compensation value of the current dispersion compensation module in the second range.

[0102] Because 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. When the first expected attenuation value is less than or equal to Voa_att_thr, the first expected attenuation value is within the first interval; when the first expected attenuation value is greater than Voa_att_thr, the first expected attenuation value is within the second interval. To ensure the accuracy of the first expected attenuation value, the first expected attenuation value calculated in the previous step needs to be optimized.

[0103] When the number of the optical attenuators is 2, the optical attenuators include a first optical attenuator and a second optical attenuator, the first optical attenuator is located in the first optical amplifier, and the second optical attenuator is located in the second optical amplifier.

[0104] When the first expected attenuation value is within the first interval, the attenuation value in the first interval is the first attenuation value, and a first set attenuation value of the first optical attenuator is obtained based on the first attenuation value; a second set attenuation value of the second optical attenuator is obtained based on the first attenuation value and the first expected attenuation value obtained in the previous step; when the first expected attenuation value is within the second interval, the attenuation value in the second interval is the second attenuation value, and the first set attenuation value of the first optical attenuator is obtained based on the first attenuation value; and a second set attenuation value of the second optical attenuator is obtained based on the second attenuation value and the first expected attenuation value obtained in the previous step.

[0105] In one embodiment, when the first expected attenuation value is within the first interval, the first set attenuation value of the first optical attenuator is Voa11_att_set, wherein Voa11_att_set=F(Voa_att_range1); the second set attenuation value of the second optical attenuator is Voa12_att_set, wherein Voa12_att_set=G(Voa_att_range1, Voa1_att_set).

[0106] When the first expected attenuation value is in 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).

[0107] Voa_att_range1 is the attenuation value of the optical attenuator in the first range, and Voa_att_range2 is the attenuation value of the optical attenuator in the second range.

[0108] To further adjust the optical performance of the dispersion compensation module and achieve gain flatness, the first expected attenuation values ​​of the first optical attenuator and the second optical attenuator are adjusted based on the difference Δ between the first expected attenuation values ​​of the first optical attenuator and the second optical attenuator. Specifically, when Δ is between [0 dB:0.3 dB], the first set attenuation value is updated to the first actual attenuation value, where the first actual attenuation value is obtained by subtracting the first set attenuation value from Δ; and the second set attenuation value is updated to the second actual attenuation value, where the second actual attenuation value is obtained by adding the first set attenuation value to Δ. When Δ is between [0.4 dB:0.6 dB], the first set attenuation value is subtracted from Δ / 2 to obtain the first actual attenuation value, and the first set attenuation value is added to Δ / 2 to obtain the second actual attenuation value.

[0109] When the first set attenuation value of the first optical attenuator is Voa11_att_set, the first set attenuation value of the second optical attenuator is Voa12_att_set, and Δ is between [0dB:0.3dB], Voa11_att_set will be updated to the first actual attenuation value Voa11_att_set_calc, where Voa11_att_set_calc=Voa11_att_set-Δ; Voa12_att_set will be updated to the second actual attenuation value Voa12_att_set_calc, where Vo a12_att_set_calc=Voa11_att_set+Δ; when Δ is between [0.4dB:0.6dB], Voa11_att_set will be updated to Voa11_att_set_calc, where Voa11_att_set_calc=Voa11_att_set-Δ / 2, and Voa12_att_set will be updated to Voa12_att_set_calc; where Voa12_att_set_calc=Voa11_att_set+Δ / 2.

[0110] When the first set attenuation value of the first optical attenuator is Voa21_att_set, the first set attenuation value of the second optical attenuator is Voa22_att_set, and Δ is between [0 dB:0.3 dB], Voa21_att_set will be updated to the first actual attenuation value Voa21_att_set_calc, where Voa21_att_set_calc=Voa21_att_set-Δ; Voa22_att_set will be updated to the second actual attenuation value Voa22_att_set_calc, where Voa22_att_set_calc=Voa21_att_set+Δ; when Δ is between [0.4 dB:0.6 dB], Voa21_att_set will be updated to Voa21_att_set_calc, where Voa21_att_set_calc=Voa21_att_set-Δ / 2, and Voa22_att_set will be updated to Voa22_att_set_calc; where Voa22_att_set_calc=Voa21_att_set+Δ / 2.

[0111] In summary, an embodiment of the present invention provides a method for adaptive amplification of optical fiber dispersion compensation. FIG2 shows an embodiment in which, when the gain slope Tilt_set is set to 0, the dispersion compensation values ​​of the dispersion compensation module are obtained as DCM = 8 dB and DCM = 12 dB, and when the gain is set as Gain_set = 13 dB and Gain_set = 20 dB, the gain slope Tilt_calc value calculated from the actual measured optical signal wavelength data is used to adaptively adjust the attenuation value of the variable optical attenuator at different gain points, so that the actual gain slope Tilt_calc meets the preset indicator requirement of ±0.5 dB with a certain margin. The gain flatness Gain_Flatness calculated from the actual measured data meets the preset indicator requirement of ±1 dB with a certain margin, thereby achieving the effect of optimizing the gain slope and gain flatness.

[0112] Example 2:

[0113] An embodiment of the present invention provides, based on Example 1, an apparatus for adaptive amplification of optical fiber dispersion compensation, which is applicable to the method for adaptive amplification of optical fiber dispersion compensation described in Example 1. As shown in FIG3 , the apparatus comprises: a dispersion compensation module, multiple optical fiber amplifiers, and a control unit; the control unit is connected to the dispersion compensation module and configured to obtain the dispersion compensation value; the optical fiber amplifier includes a variable optical attenuator, the control unit is connected to the variable optical attenuator, and configured to configure the gain of the optical fiber amplifier and adjust the attenuation value of the variable optical attenuator; the multiple optical fiber amplifiers are cascaded, the dispersion compensation module is located between two optical fiber amplifiers, the input end of the dispersion compensation module is connected to the preceding optical fiber amplifier, and the output end of the dispersion compensation module is connected to the following optical fiber amplifier.

[0114] As shown in FIG4 , the optical fiber amplifier further includes an erbium-doped optical fiber and a pump source. The control unit is further connected to the control end of the pump source to drive the pump source according to the allocated gain. The output end of the pump source is connected to the erbium-doped optical fiber, and the erbium-doped optical fiber is connected to the variable optical attenuator.

[0115] Figure 3 shows a schematic diagram of a dispersion compensation module performing dispersion compensation on two optical fiber amplifiers, according to one embodiment. Dispersion compensation and gain are closely linked in optical communications. Dispersion can cause signal distortion during transmission, while gain is a parameter used to adjust signal strength or quality. To compensate for dispersion effects, a certain amount of gain is typically required to ensure signal quality and stability after transmission. In optical communication systems, dispersion can cause signal pulse broadening, resulting in signal distortion during transmission. To mitigate this effect, a dispersion compensation module is employed to provide an opposite effect to dispersion, thereby reducing or eliminating signal distortion. However, dispersion compensation does not always completely eliminate signal distortion. To further improve signal quality, signal amplification—increasing gain—is required. Gain can be used to adjust signal strength or amplitude, thereby compensating for signal attenuation or distortion caused by dispersion. By properly setting the gain value, the signal can be ensured to remain stable and high quality after dispersion compensation. Therefore, in this embodiment, the dispersion compensation module uses appropriate gain allocation and dispersion compensation for the optical fiber amplifiers, effectively ensuring that the signal remains stable and high quality after dispersion compensation. In actual application scenarios, the number of optical fiber amplifiers can be determined according to actual needs and is not excessively limited in this embodiment.

[0116] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for adaptive amplification of optical fiber dispersion compensation, characterized in that: include: Obtaining the dispersion compensation value of the dispersion compensation module; reallocating the total gain of the dispersion compensation module to the plurality of optical fiber amplifiers according to the dispersion compensation value; calculating a first expected attenuation value of a variable optical attenuator located in each optical fiber amplifier based on the redistributed gain of each optical fiber amplifier, and calculating an attenuation compensation amount of 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, and dynamically configuring the variable optical attenuator based on the second expected attenuation value; Calculating an actual attenuation value according to the detection power at the first input end and the detection power at the first output end of the variable optical attenuator; The actual attenuation value is compared with the second expected attenuation value. If they are consistent, the adjustment of the variable optical attenuator is stopped; otherwise, the adjustment of the variable optical attenuator is continued.

2. The method for adaptive amplification of optical fiber dispersion compensation according to claim 1, characterized in that: When the number of the optical fiber amplifiers is 2, the optical fiber amplifiers include a first optical fiber amplifier and a second optical fiber amplifier; wherein the gain of the first optical fiber amplifier after redistribution is the first gain, and the gain of the second optical fiber amplifier after redistribution is the second gain; The redistributing the total gain of the dispersion compensation module to the plurality of optical fiber amplifiers according to the dispersion compensation value specifically includes: Determining the interval to which the dispersion compensation value belongs according to the dispersion compensation threshold DCM_Thr, if the dispersion compensation value is less than or equal to DCM_Thr, the dispersion compensation value is in a first interval; if the dispersion compensation value is greater than DCM_Thr, the dispersion compensation value is in a second interval; When the gain slope of the dispersion compensation module is set to 0, if the dispersion compensation value is in a first range, the dispersion compensation value in the first range is the first dispersion compensation value, and a first gain of the first optical fiber amplifier is obtained according to the expected gain, the first dispersion compensation value, and the set gain slope set in the dispersion compensation module; and a second gain of the second optical fiber amplifier is obtained according to a dispersion compensation threshold and the set gain slope. If the dispersion compensation value is in a second range, the first gain of the first optical fiber amplifier is obtained according to the expected gain and the set gain slope set in the dispersion compensation module; and a second gain of the second optical fiber amplifier is obtained according to the dispersion compensation threshold and the set gain slope.

3. The method for adaptive amplification of optical fiber dispersion compensation according to claim 2, characterized in that: When the gain slope of the dispersion compensation module is set to not be 0, the distribution values ​​of the first gain and the second gain specifically include: When the dispersion compensation value is within the first interval, a first gain of the first optical fiber amplifier is obtained according to the desired gain set in the dispersion compensation module, the first dispersion compensation value, and the absolute value of the calculated gain slope; and a second gain of the second optical fiber amplifier is obtained according to the dispersion compensation threshold and the absolute value of the calculated gain slope. When the dispersion compensation value is in the second interval, the first gain of the first optical fiber amplifier is obtained according to the expected gain set in the dispersion compensation module and the absolute value of the gain slope; and the second gain of the second optical fiber amplifier is obtained according to the dispersion compensation threshold and the absolute value of the calculated gain slope.

4. The method for adaptive amplification of optical fiber dispersion compensation according to claim 2, characterized in that: The detection power at the second input end and the detection power at the second output end of the first optical fiber amplifier are feedback closed-loop controlled; The detection power at the third input end and the detection power at the third output end of the second optical fiber amplifier are controlled by feedback closed loop.

5. The method for adaptive amplification of optical fiber dispersion compensation according to claim 2, characterized in that: The total gain is the sum of the first gain and the second gain.

6. The method for adaptive amplification of optical fiber dispersion compensation according to claim 1, characterized in that: Calculating the first expected attenuation value of the variable optical attenuator located in each optical fiber amplifier according to the redistributed gain of each optical fiber amplifier specifically includes: The dispersion compensation value is a variable value, and is divided into a first interval and a second interval according to a dispersion compensation threshold DCM_Thr. If the dispersion compensation value is less than or equal to DCM_Thr, the dispersion compensation value is in the first interval; if the dispersion compensation value is greater than DCM_Thr, the dispersion compensation value is in the second interval. When the dispersion compensation value is in the first interval, the dispersion compensation value in the first interval is the first dispersion compensation value, and a first expected attenuation value is obtained based on the expected gain set in the dispersion compensation module and the first dispersion compensation value. When the dispersion compensation value is in the second interval, the dispersion compensation value in the second interval is a second dispersion compensation value, and the first expected attenuation value is obtained according to the set expected gain and the second dispersion compensation value.

7. The method for adaptive amplification of optical fiber dispersion compensation according to claim 6, characterized in that: 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 according to the attenuation threshold Voa_att_thr; When the first expected attenuation value is less than or equal to Voa_att_thr, the first expected attenuation value is located in a first interval; when the first expected attenuation value is greater than Voa_att_thr, the first expected attenuation value is located in a second interval; When the number of the optical attenuators is 2, 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; When the first expected attenuation value is within the first interval, the attenuation value in the first interval is the first attenuation value, and a first set attenuation value of the first optical attenuator is obtained according to the first attenuation value; and a second set attenuation value of the second optical attenuator is obtained according to the first attenuation value and the first expected attenuation value obtained in the previous step. When the first expected attenuation value is within the second interval, the attenuation value in the second interval is a second attenuation value. A first set attenuation value of the first optical attenuator is obtained based on the first attenuation value. A second set attenuation value of the second optical attenuator is obtained based on the second attenuation value and the first expected attenuation value obtained in the previous step.

8. The method for adaptive amplification of optical fiber dispersion compensation according to claim 7, characterized in that: Adjusting the first expected attenuation values ​​of the first optical attenuator and the second optical attenuator respectively according to the difference Δ between the first expected attenuation values ​​of the first optical attenuator and the second optical attenuator specifically includes: When Δ is between [0dB:0.3dB], the first set attenuation value will be updated to the first actual attenuation value, where the first set attenuation value and Δ are subtracted to obtain the first actual attenuation value; the second set attenuation value will be updated to the second actual attenuation value, where the first set attenuation value and Δ are added to obtain the second actual attenuation value; When Δ is between [0.4 dB:0.6 dB], the first set attenuation value is subtracted from Δ / 2 to obtain a first actual attenuation value, and the first set attenuation value is added to Δ / 2 to obtain a second actual attenuation value.

9. The method for adaptive amplification of optical fiber dispersion compensation according to any one of claims 1 to 8, characterized in that: If the actual attenuation value is inconsistent with the second expected attenuation value, the DAC value of the variable optical attenuator is adjusted to make the actual attenuation value consistent with the second expected attenuation value.

10. The method for adaptive amplification of optical fiber dispersion compensation according to any one of claims 1 to 8, characterized in that: 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 preset moment.

11. The method for adaptive amplification of optical fiber dispersion compensation according to any one of claims 1 to 8, characterized in that: The attenuation compensation amount is obtained according to the gain value actually set at the preset moment, the optical power input at the preset moment, and the shell temperature of the optical fiber amplifier at the preset moment.

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

13. The method for adaptive amplification of optical fiber dispersion compensation according to any one of claims 1 to 8, characterized in that: The actual attenuation value is obtained by subtracting the detection power at the first output end from the detection power at the first input end.

14. A device for adaptive amplification of optical fiber dispersion compensation, applicable to the method for adaptive amplification of optical fiber dispersion compensation according to any one of claims 1 to 8, characterized in that: include: 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 the control unit is used to obtain 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 configure the gain of the optical fiber amplifier and adjust the attenuation value of the variable optical attenuator; The multiple fiber amplifiers are cascaded, the dispersion compensation module is located between two fiber amplifiers, the input end of the dispersion compensation module is connected to the previous fiber amplifier, and the output end of the dispersion compensation module is connected to the next fiber amplifier.

15. The optical fiber dispersion compensation and adaptive amplification device according to claim 14, characterized in that: The optical fiber amplifier further comprises an erbium-doped optical fiber and a pump source, and the control unit is further connected to a control end of the pump source to drive the pump source according to the allocated gain; The output end of the pump source is connected to the erbium-doped optical fiber, and the erbium-doped optical fiber is connected to the variable optical attenuator.

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