Method for determining a power compensation value of an optical signal and related device - Patents.com

Abstract

SUMMARY OF THE INVENTION The embodiments of the present application disclose a method and related apparatus for determining a power compensation value of an optical signal that improves the stability of signal transmission. A method in an embodiment of the present application includes the steps of: obtaining a first optical signal and a second optical signal, where the first optical signal is an optical signal obtained by adding or dropping a wavelength to or from the second optical signal; detecting a first optical power of each frequency band in the first optical signal and a second optical power of each frequency band in the second optical signal; calculating, based on the first optical power, a first optical power fluctuation of each frequency band of the first optical signal, which is used after the first optical signal is transmitted from a transmitting end to a receiving end; calculating, based on the second optical power, a second optical power fluctuation of each frequency band of the second optical signal, which is used after the second optical signal is transmitted from the transmitting end to a receiving end; and determining, based on the first optical power fluctuation and the second optical power fluctuation, a first compensation value and a second compensation value, where the first compensation value is used to compensate for the total power of the first optical signal and the second compensation value is used to compensate for the power spectrum tilt of the first optical signal.

Description

[Technical field]

[0001] The present application relates to the field of optical communications, and in particular to a method and related apparatus for determining a power compensation value of an optical signal. [Background technology]

[0002] This application claims priority to Chinese Patent Application No. 202011200618.4, entitled “Method for determining power compensation value of optical signal and related apparatus,” filed with the China State Intellectual Property Office on October 30, 2020, and is incorporated herein in its entirety.

[0003] With the rapid increase of data traffic in the network, higher requirements are imposed on the transmission capacity of the network. In general, in order to increase the network transmission capacity, the channel operating spectrum width (the number of channels) may be increased, for example, the original C band is extended to C band and L band.

[0004] However, as the spectral width of the channel widens, the stimulated Raman scattering (SRS) effect occurs in the multi-wavelength transmission system link, and the transmission power of the short band is transferred to the transmission power of the long band. In a stable state without wavelength adding or dropping, the power transfer between multi-wavelength signals caused by the SRS effect is stable. When wavelength adding or dropping occurs, the quantity, distribution, position, etc. of the multi-wavelength signals will change randomly. As a result, complex changes will occur in the power transfer between multi-wavelength signals, which may exceed the system's tolerance capability, and the stability of signal transmission will be reduced. Summary of the Invention

[0005] The embodiments of the present application provide a method and related device for determining the power compensation value of an optical signal, so that in the process of transmitting an optical signal in an optical fiber, the power change caused by the SRS effect does not exceed the system tolerance capability, and the power spectrum tilt used before and after wavelengths are added or dropped to the optical signal is consistent, thereby improving the stability of signal transmission.

[0006] According to a first aspect, an embodiment of the present application provides a method for determining a power compensation value of an optical signal, the method comprising the steps of:

[0007] First, a first optical signal and a second optical signal are obtained, where the first optical signal is an optical signal obtained by adding or dropping a wavelength to the second optical signal. The second optical signal includes at least one wavelength signal, and the at least one wavelength signal of the second optical signal is dispersed into at least one frequency band. The first optical signal includes at least one wavelength signal, and the at least one wavelength signal of the first optical signal is dispersed into at least one frequency band. The wavelength signal of the first optical signal is dispersed into any frequency band corresponding to the first optical signal, and the wavelength signal of the second optical signal is dispersed into any frequency band corresponding to the second optical signal. Next, a first optical power of each frequency band in the first optical signal and a second optical power of each wavelength band in the second optical signal are detected. Then, a first optical power fluctuation in each frequency band of the first optical signal, which is used after the first optical signal is transmitted from the transmitting end to the receiving end, is calculated based on the first optical power, and a second optical power fluctuation in each frequency band of the second optical signal, which is used after the second optical signal is transmitted from the transmitting end to the receiving end, is calculated based on the second optical power. Furthermore, a first compensation value and a second compensation value are determined based on the first optical power fluctuation and the second optical power fluctuation, where the first compensation value is used to compensate for the total power of the first optical signal, and the second compensation value is used to compensate for the power spectrum tilt of the first optical signal.

[0008] In this implementation, before the first optical signal is transmitted, the total power of the first optical signal can be compensated based on the first compensation value, so that the power change caused by the SRS effect in the transmission process of the first optical signal in the optical fiber does not exceed the system tolerance capability, thereby improving the stability of the signal transmission. In addition, the power spectrum tilt of the first optical signal can be further compensated based on the second compensation value, so that the power spectrum tilts of the first optical signal and the second optical signal received by the signal receiving end are consistent, thereby further improving the stability of the signal transmission.

[0009] In some possible implementations, the method further includes: obtaining a first coefficient and a second coefficient, the first coefficient being related to a transmission type of the signal, and the second coefficient being related to an optical power transfer per two frequency bands; determining a first optical power variation for each frequency band of the first optical signal based on the first optical power and to be used after the first optical signal is transmitted from the transmitting end to the receiving end includes calculating a first optical power variation based on the first optical power, the first coefficient, and the second coefficient; determining a second optical power variation for each frequency band of the second optical signal based on the second optical power and to be used after the second optical signal is transmitted from the transmitting end to the receiving end includes calculating a second optical power variation based on the second optical power, the first coefficient, and the second coefficient. In this implementation, a specific implementation of calculating the first optical power variation and the second optical power variation is provided, thereby improving the implementability of this solution.

[0010] In some possible implementations, the method further includes obtaining a ratio of the optical power of each waveband in the first optical signal to a total power of the first optical signal. Determining the first compensation value based on the first optical power fluctuation and the second optical power fluctuation includes substituting the first optical power fluctuation, the second optical power fluctuation, and the ratio into a first equation to calculate the first compensation value. The first equation is

[0011]

number

[0012] where C1 represents the first compensation value, i represents the sequence number of the frequency band, M represents the quantity of the frequency band, Si1 represents the second optical power fluctuation of the frequency band i in the second optical signal, Si2 represents the first optical power fluctuation of the frequency band i in the first optical signal, and Xi represents the ratio. In this implementation, a specific implementation for calculating the first compensation value is provided, so that the power compensation value of the first optical signal can be calculated more accurately.

[0013] In some possible implementations, determining the second compensation value based on the first optical power fluctuation and the second optical power fluctuation includes substituting the first optical power fluctuation of the first segment waveband in the first optical signal, the first optical power fluctuation of the final segment waveband in the first optical signal, the second optical power fluctuation of the first segment waveband in the second optical signal, and the second optical power fluctuation of the final segment waveband in the second optical signal into a second equation to calculate the second compensation value. The second formula includes C2=(S1max-S1min)-(S2max-S2min), where C2 represents the second compensation value, S1max represents the first optical power fluctuation of the frequency band of the last segment in the first optical signal, S1min represents the first optical power fluctuation of the frequency band of the first segment in the first optical signal, S2max represents the second optical power fluctuation of the frequency band of the last segment in the second optical signal, and S2min represents the second optical power fluctuation of the frequency band of the first segment in the second optical signal. In this implementation, a specific implementation of calculating the second compensation value is provided, so that this solution is more practical.

[0014] In some possible implementations, the method further includes compensating a total power of the first optical signal based on the first compensation value and compensating a power spectral tilt of the first optical signal based on the second compensation value.

[0015] In some possible implementations, compensating the total power of the first optical signal based on the first compensation value includes adjusting a pump current in the optical amplifier based on the first compensation value, and adjusting an output power of the first optical signal after the first optical signal passes through the optical amplifier. In this implementation, a specific implementation of optical amplifier-based power compensation is provided, and the power compensation may be completed accurately based on the first compensation value.

[0016] In some possible implementations, compensating for the power spectral tilt of the first optical signal based on the second compensation value includes: and adjusting the attenuation of a variable optical attenuator VOA in the optical amplifier based on the second compensation value to adjust the power spectral tilt of the first optical signal, which is used after the first optical signal passes through the optical amplifier. In this implementation, a specific implementation of VOA-based power spectral tilt compensation is provided, and the power spectral tilt compensation may be accurately completed based on the second compensation value.

[0017] In some possible implementations, detecting the first optical power of each frequency band in the first optical signal includes splitting the first optical signal into optical signals of multiple frequency bands via a filter and detecting the first optical power of each frequency band in the first optical signal via a power detector. Detecting the second optical power of each frequency band in the second optical signal includes splitting the second optical signal into optical signals of multiple frequency bands via a filter and detecting the second optical power of each frequency band in the second optical signal via a power detector. In this implementation, the filter and the power detector may be used together to detect the power of each frequency band, thereby improving the practicality of this solution.

[0018] In some possible implementations, detecting the first optical power of each frequency band in the first optical signal includes detecting the first optical power of each wavelength in the first optical signal via an optical spectrum analyzer (OSA) or an optical performance monitor (OPM). Detecting the second optical power of each frequency band in the second optical signal includes detecting the second optical power of each wavelength in the second optical signal via an OSA or an OPM. In this implementation, the OSA and OPM have the capability to detect signals within a particular wavelength range. Thus, there is no need to configure a filter, and the output amount of the OSA and OPM still detects the first optical power of each frequency band. Obi power, which increases the scalability of the solution.

[0019] According to a second aspect, an embodiment of the present application provides a power calculation device including a processor, a memory, and an optical detection module. The processor, the memory, and the optical detection module are connected to each other via a line. The optical detection module obtains a first optical signal and a second optical signal, the first optical signal being an optical signal obtained by adding or dropping a wavelength to the second optical signal, the second optical signal including at least one wavelength signal, the at least one wavelength signal of the second optical signal being distributed into at least one frequency band, the first optical signal including at least one wavelength signal, the at least one wavelength signal of the first optical signal being distributed into at least one frequency band, the wavelength signal of the first optical signal being distributed into any frequency band corresponding to the first optical signal, the wavelength signal of the second optical signal being distributed into any frequency band corresponding to the second optical signal, and detects a first optical power of each frequency band in the first optical signal and a second optical power of each frequency band in the second optical signal. the processor is configured to: determine, based on the first optical signal, a first optical power fluctuation of each wavelength of the first optical signal, which is a first optical power fluctuation to be used after the first optical signal is transmitted from the transmitting end to the receiving end; determine, based on the second optical power, a second optical power fluctuation of each wavelength of the second optical signal, which is a second optical power fluctuation to be used after the second optical signal is transmitted from the transmitting end to the receiving end; determine a first compensation value based on the first optical power fluctuation and the second optical power fluctuation, where the first compensation value is used to compensate for a total power of the first optical signal; determine a second compensation value based on the first optical power fluctuation and the second optical power fluctuation, where the second compensation value is used to compensate for a power spectral tilt of the first optical signal.

[0020] In some possible implementations, the processor is further configured to obtain a first coefficient and a second coefficient, where the first coefficient is associated with a transmission type of the signal and the second coefficient is associated with an optical power transfer for each of the two frequency bands, and the processor is particularly configured to calculate a first optical power fluctuation based on the first optical power, the first coefficient, and the second coefficient, and to calculate a second optical power fluctuation based on the second optical power, the first coefficient, and the second coefficient.

[0021] In some possible implementations, the processor is further configured to obtain a ratio of the optical power of each waveband in the first optical signal to a total power of the first optical signal, and the processor is particularly configured to calculate the first compensation value by substituting the first optical power fluctuation, the second optical power fluctuation, and the ratio into a first equation, where the first equation is defined as:

[0022]

number

[0023] where C1 represents a first compensation value, i represents a sequence number of the frequency band, M represents a quantity of the frequency bands, Si1 represents a second optical power fluctuation of the frequency band i in the second optical signal, Si2 represents a first optical power fluctuation of the frequency band i in the first optical signal, and Xi represents a ratio.

[0024] In some possible implementations, the processor is specifically configured to calculate the second compensation value by substituting the first optical power variation of the first segment waveband in the first optical signal, the first optical power variation of the final segment waveband in the first optical signal, the second optical power variation of the first segment waveband in the second optical signal, and the second optical power variation of the final segment waveband in the second optical signal into a second equation, the second equation comprising: C2=(S1max-S1min)-(S2max-S2min), where C2 represents the second compensation value, S1max represents the first optical power variation of the final segment waveband in the first optical signal, S1min represents the first optical power variation of the first segment waveband in the first optical signal, S2max represents the second optical power variation of the final segment waveband in the second optical signal, and S2min represents the second optical power variation of the first segment waveband in the second optical signal.

[0025] In some possible implementations, the processor is further configured to compensate a total power of the first optical signal based on the first compensation value and to compensate a power spectral tilt of the first optical signal based on the second compensation value.

[0026] In some possible implementations, the processor is particularly configured to adjust a pump current in the optical amplifier based on the first compensation value to adjust an output power of the first optical signal after the first optical signal passes through the optical amplifier.

[0027] In some possible implementations, the processor is specifically configured to adjust, based on the second compensation value, the attenuation of a variable optical attenuator VOA within the optical amplifier to adjust a power spectral tilt of the first optical signal that is used after the first optical signal passes through the optical amplifier.

[0028] In some possible implementations, the optical detection module includes a filter and a power detector. The filter is configured to split the first optical signal into optical signals of multiple frequency bands and split the second optical signal into optical signals of multiple frequency bands. The power detector is configured to detect a first optical power of each frequency band in the first optical signal and detect a second optical power of each frequency band in the second optical signal.

[0029] In some possible implementations, the optical detection module includes an OSA or an OPM configured to detect a first optical power for each wavelength in the first optical signal and to detect a second optical power for each wavelength in the second optical signal.

[0030] According to a third aspect, an embodiment of the present application provides an optical transmission system including a first site and a second site, the first site configured to perform a method for determining a power compensation value of an optical signal according to any implementation of the first aspect, and the second site configured to receive the optical signal output by the first site.

[0031] In some possible implementations, the first site includes an optical amplifier site or a Reconfigurable Optical Add / Drop Multiplexer (ROADM) site.

[0032] According to the above technical solutions, it can be seen that the embodiments of the present application have the following advantages:

[0033] In an embodiment of the present application, the first optical signal is an optical signal obtained by adding or dropping a wavelength to the second optical signal, and the signal transmitting end needs to detect the first optical power of each frequency band in the first optical signal and the second optical power of each frequency band in the second optical signal. Then, after the first optical signal is transmitted from the transmitting end to the receiving end, the first optical power fluctuation caused by the SRS effect in each frequency band may be calculated based on the first optical power, and after the second optical signal is transmitted from the transmitting end to the receiving end, the second optical power fluctuation caused by the SRS effect in each frequency band may be calculated based on the second optical power. Then, the first compensation value and the second compensation value may be determined based on the first optical power fluctuation and the second optical power fluctuation. Furthermore, before the first optical signal is transmitted, the total power of the first optical signal may be compensated based on the first compensation value, so as to ensure that the power change caused by the SRS effect in the process of transmitting the first optical signal in the optical fiber does not exceed the system tolerance capability, thereby improving the stability of the signal transmission. Furthermore, the power spectral tilt of the first optical signal may be further compensated based on the second compensation value, so that the power spectral tilts of the first optical signal and the second optical signal received by the signal receiving end are consistent, thereby further improving the stability of signal transmission. [Brief description of the drawings]

[0034] [Figure 1] 1 is a schematic diagram of the structure of an optical transmission system used in this application; [Diagram 2] 2 is a schematic diagram of an embodiment of a method for determining a power compensation value of an optical signal according to the present application; [Diagram 3] 1 is a schematic diagram of an embodiment in which a multi-wavelength signal is dispersed into multiple wavebands. [Figure 4] 1 is a schematic diagram of an embodiment of optical power detection according to the present application; [Diagram 5]4 is a schematic diagram of another embodiment of optical power detection according to the present application. [Figure 6] 1 is a schematic diagram of an embodiment of power transfer between wavebands. [Figure 7] 3 is a schematic diagram of an embodiment of a power change of an optical signal. [Figure 8] 1 is a schematic diagram of the structure of an optical amplifier according to an embodiment of the present application; [Figure 9] FIG. 2 is a schematic diagram of the structure of a power calculation device. [Figure 10] FIG. 1 is a schematic diagram of the structure of an optical transmission system according to an embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] The embodiments of the present application provide a method and related device for determining a power compensation value of an optical signal, so that the power change caused by the SRS effect in the process of transmitting an optical signal through an optical fiber does not exceed the system tolerance capability. Furthermore, the power spectrum tilt used before and after the wavelength adding or dropping performed on the optical signal is consistent, thereby improving the stability of signal transmission.

[0036] It should be noted that the terms "first," "second," "third," "fourth," etc. in the specification, claims, and accompanying drawings of this application are used to distinguish between similar objects, but are not intended to limit a particular order or sequence. It should be understood that the above terms are interchangeable under appropriate circumstances, and that the embodiments described in this application can be implemented in other orders than those described in this application. Furthermore, the terms "include," "have," or any other variations thereof are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units explicitly recited, and may include other steps and units that are not explicitly recited or are essential to the process, method, product, or device.

[0037] 1 is a schematic diagram of the structure of an optical transmission system used in this application. The optical transmission system includes at least a first site 10 and a second site 20. The first site 10 includes an optical amplifier 101, a coupler 102, and a power detection device 103. 2 The site 20 includes an optical amplifier 201, a coupler 202, and a power detector 203. As shown in Fig. 1, the first site 10 may transmit a multi-wavelength signal to the second site 20 via an optical fiber. The transmission of the multi-wavelength signal in the optical fiber is affected by the Stimulated Raman Scattering (SRS) effect, and thus the transmission power of the short band is transferred to the transmission power of the long band.

[0038] It should be understood that when no wavelength add or drop is performed on the current multi-wavelength signal, the power transfer between the multi-wavelength signals caused by the SRS effect is stable. When wavelength add or drop occurs, the quantity, distribution, position, etc. of the multi-wavelength signals change randomly. Therefore, complex changes occur in the power transfer between the multi-wavelength signals, and such power changes may exceed the system tolerance capability. Therefore, in this application, a power detection device 103 is disposed at the first site 10. Before the multi-wavelength signal output by the first site 10 enters the optical fiber, the power detection device 103 may pre-calculate the power change caused by the SRS effect. Furthermore, the first site 10 may compensate the transmission power of the multi-wavelength signal based on the calculation result. This avoids complex changes in the power transfer between the multi-wavelength signals in the transmission process, thereby improving the stability of the signal transmission.

[0039] Specifically, the coupler 102 may split the signal output by the optical amplifier 101 into different channels. The signal in one channel is coupled to an optical fiber for transmission to the second site 20. The signal in another channel is coupled to a power detector 103 to calculate the power change caused by the SRS effect. The power detector 103 calculates the power value that needs to be compensated and outputs the compensation value to the optical amplifier 101, which then performs the power compensation on the output signal. It should be understood that the coupler 102 splits the signal based on a power ratio, and the wavelengths contained in the signals of each channel are the same. For example, the coupler 102 may split the signal based on a power ratio of 99:1, and most of the signal needs to be coupled to the optical fiber and only a few signals need to be reserved for detection and calculation.

[0040] It should be noted that the type of the optical amplifier mentioned above may be an Erbium Doped Fiber Application Amplifier (EDFA), a Semiconductor Optical Amplifier (SOA), etc., and may be an integrated amplifier or separate amplifiers. This is not particularly limited in this specification. The first site 10 and the second site 20 may each be another type of site other than the optical amplifier site shown in FIG. 1, for example, a Reconfigurable Optical Add / Drop Multiplexer (ROADM) site. This is not particularly limited in this specification.

[0041] In the following, a method for determining the power compensation value of an optical signal provided in this application is described.

[0042] 2 is a schematic diagram of an embodiment of a method for determining a power compensation value of an optical signal according to the present application. In this example, the method for determining a power compensation value of an optical signal includes the following steps:

[0043] 201: Obtain a first optical signal and a second optical signal.

[0044] In this embodiment, the first optical signal is an optical signal obtained by adding or dropping a wavelength to the second optical signal. The second optical signal may be a single wavelength signal or a multi-wavelength signal. The second optical signal is distributed into at least one frequency band, and different frequency bands correspond to different wavelength signals. In addition, each wavelength signal has a corresponding wavelength value, and each frequency band includes the wavelength value of at least one wavelength signal. By adding or dropping a wavelength to the second optical signal, the first optical signal can be a single wavelength signal or a multi-wavelength signal. It should be understood that when the second optical signal is a single wavelength signal, the first optical signal is a multi-wavelength signal obtained by adding a wavelength to the second optical signal. When the first optical signal is a single wavelength signal, the second optical signal is a multi-wavelength signal, and the first optical signal is obtained by dropping a wavelength to the second optical signal. That is, the first optical signal and the second optical signal have the same frequency band and also have different frequency bands. For ease of explanation, in this application, the channel number of the wavelength signal is used to distinguish the wavelength signals (Ch1, Ch2, etc.). The wavelength value of each wavelength signal may be determined based on the channel number of the wavelength signal. These wavelength signals may belong to either the C-band or the L-band. This is not particularly limited in this specification. It should be noted that the first optical signal may be a full-wavelength signal (obtained by performing a wavelength add to the second optical signal) or may not be a full-wavelength signal. The second optical signal may be a full-wavelength signal (obtained by performing a wavelength drop to the second optical signal) or may not be a full-wavelength signal.

[0045] FIG. 3 is a schematic diagram of an embodiment in which a multi-wavelength signal is distributed into multiple frequency bands. For example, in the present application, the second optical signal is a full-wavelength signal and includes 100 wavelength signals from Ch1 to Ch100, and the 100 wavelength signals are distributed into 10 different frequency bands. Every 10 consecutive wavelength signals are distributed into the same frequency band. For example, wavelength signals Ch1 to Ch10 are distributed into frequency band 1, wavelength signals Ch11 to Ch20 are distributed into frequency band 2, ..., wavelength signals Ch91 to Ch100 are distributed into frequency band 10. In the present application, the first optical signal includes six wavelength signals, namely Ch1, Ch3, Ch5, Ch96, Ch98, and Ch100. Wavelength signals Ch1, Ch3, and Ch5 are distributed into frequency band 1, and wavelength signals Ch96, Ch98, and Ch100 are distributed into frequency band 10.

[0046] It should be noted that in this application, the number of wavebands is not limited and may be 10, 20, 30, etc. as mentioned above. In practical application, the wavebands may be divided in multiple ways, and the ways may include the equal division way shown in FIG. 3 and the non-equal division way in which different wavebands correspond to different quantities of wavelength signals. In addition, the wavebands may also have different division granularities. For example, each waveband may correspond to multiple wavelength signals as shown in FIG. 3. Alternatively, each waveband may uniquely correspond to one wavelength signal. This is not particularly limited in this specification. The total number of available wavelengths is also not limited in this application and may be 100 available wavelengths as shown in FIG. 3, or 120 available wavelengths, 200 available wavelengths, etc.

[0047] 202: Detect a first optical power of each waveband in the first optical signal, and a second optical power of each waveband in the second optical signal.

[0048] In this embodiment, the optical power detection can be specifically implemented in several ways, which are described separately below.

[0049] Type 1: Implementation using a filter and a power detector (PD) together

[0050] FIG. 4 is a schematic diagram of an embodiment of optical power detection according to the present application. As shown in FIG. 4, a plurality of filters 401 and a plurality of PDs (402) are included, with one-to-one correspondence. The optical signal of each frequency band has a corresponding group of filters and PDs. Each filter can filter the optical signal that is within the frequency band corresponding to the filter, and then each PD detects the optical power of the corresponding frequency band. Take FIG. 3 as an example. If the second optical signal is distributed from frequency band 1 to frequency band 10, at least ten groups of filters and PDs need to be arranged. When the second optical power of each frequency band in the second optical signal is detected, all ten PDs need to work. When the first optical power of each frequency band in the first optical signal is detected, only the optical power of frequency band 1 and the optical power of frequency band 10 need to be detected through the first PD and the tenth PD, respectively.

[0051] It should be noted that the filters may be of a separate design, specifically as shown in Figure 4, or may be in another form, such as an integrated design or in the form of a cascaded filter, which is not specifically limited herein.

[0052] In some possible implementations, the optical power detected by the PD may alternatively be collected by setting a data collector 403. The data collector may be specifically implemented by a component having a data collection function, such as an analog-to-digital converter (ADC).

[0053] Type 2: An implementation that performs power detection by using a spectrum detector

[0054] FIG. 5 is a schematic diagram of another embodiment of optical power detection according to the present application. As shown in FIG. 5, a spectrum detector 501 may detect the spectrum information of an optical signal, for example, detect the optical power of each wavelength signal. Furthermore, a data collector 502 collects the power detected by the spectrum detector 501. It should be understood that the spectrum detector 501 can detect a signal in a specific wavelength range. Therefore, there is no need to set a filter. The output amount of the spectrum detector 501 can still be detected by the optical power of each frequency band. Obi The spectrum detector may be, for example, an optical spectrum analyzer (OSA) or an optical performance monitor (OPM), which is not limited in this specification.

[0055] 203: Determine, based on the first optical power, a first optical power fluctuation which is a first optical power fluctuation for each frequency band of the first optical signal and is used after the first optical signal is transmitted from the transmitting end to the receiving end; and determine, based on the second optical power, a second optical power fluctuation which is a second optical power fluctuation for each frequency band of the second optical signal and is used after the second optical signal is transmitted from the transmitting end to the receiving end.

[0056] The transmission of an optical signal in an optical fiber may be affected by the SRS effect, which may result in power changes. Therefore, before the optical signal is coupled into the optical fiber, it is necessary to pre-calculate the power fluctuation caused by the SRS effect in each frequency band of the optical signal (including the first optical signal and the second optical signal). It should be understood that the power fluctuation in each frequency band may also be referred to as power transfer amount, net power gain, etc. The specific name of the power fluctuation is not limited in this application.

[0057] FIG. 6 is a schematic diagram of an embodiment of power transfer between frequency bands. As shown in FIG. 6, the optical signal is divided into a total of seven frequency bands, and the power transfer of frequency band 4 is used as an example for illustration. Affected by the SRS effect, the power of frequency band 3 in frequency band 1 is transferred to frequency band 4, and the power of frequency band 4 is also transferred from frequency band 5 to frequency band 7. That is, frequency band 1 to frequency band 3 will bring power gain to frequency band 4, and frequency band 5 to frequency band 7 will bring power loss to frequency band 4. Therefore, the power fluctuation of frequency band 4 relative to the other six frequency bands needs to be calculated separately, and then the total power fluctuation of frequency band 4 affected by the SRS effect can be obtained by summing up the fluctuations.

[0058] This embodiment provides a specific calculation method for calculating the power fluctuation of a frequency band, and a detailed description is provided below.

[0059] First, a first coefficient and a second coefficient need to be obtained. The first coefficient is a certain coefficient related to the transmission type of the signal. Specifically, the transmission type of the signal may include fiber length, fiber type, optical amplifier type, etc. It should be understood that, in general, after the network is constructed, parameters such as fiber length, fiber type, and optical amplifier type may be determined, and these parameters may be pre-stored and periodically updated. In this case, the corresponding first coefficient may be queried based on a data table pre-stored in the local memory. The data table may be shown in Table 1.

[0060] [Table 1]

[0061] The second coefficient is related to the optical power transfer for each of the two frequency bands. Specifically, the second coefficient may be expressed as Ti,j, which means the power transfer coefficient of frequency band i to frequency band j. Using FIG. 6 as an example, T4,1 represents the power transfer coefficient of frequency band 4 to frequency band 1. Since frequency band 1 brings a power gain to frequency band 4, T4,1 is a positive value. T4,7 represents the power transfer coefficient of frequency band 4 to frequency band 7. Since frequency band 7 brings a power loss to frequency band 4, T4,7 is a negative value. It should be understood that the second coefficient may also be pre-stored in a local memory in the form of a data table to facilitate querying during calculation. The data table may be shown in Table 2.

[0062] [Table 2]

[0063] Furthermore, the power fluctuation of each frequency band is the optical power of each frequency band in the optical signal (including the first optical signal and the second optical signal), and is calculated based on the optical power calculated in step 202, the first coefficient, and the second coefficient. Specifically, the power fluctuation may be calculated according to the following formula. The formula is:

[0064]

number

[0065] where Si represents the total power variation of waveband i, A represents the first coefficient, M represents the number of wavebands, Ti, j represent the second coefficients, and Pi represents the optical power of waveband i.

[0066] 204: Determine a first compensation value based on the first optical power fluctuation and the second optical power fluctuation, and determine a second compensation value based on the first optical power fluctuation and the second optical power fluctuation.

[0067] In this embodiment, the first compensation value is used to compensate the total power of the first optical signal, and the second compensation value is used to compensate the power spectrum tilt of the first optical signal. The following provides an explanation using an example. FIG. 7 is a schematic diagram of an embodiment of the power change of an optical signal. As shown in FIG. 7, L0 represents the power spectrum of the second optical signal. L1 represents the power spectrum of the first optical signal. L2 represents the power spectrum obtained by performing power compensation on the first optical signal based on the first compensation value. It can be seen that after performing compensation based on the first compensation value, the total power of the first optical signal matches the total power of the second optical signal, but the power spectrum tilts of the first optical signal and the second optical signal do not match, specifically, the power fluctuation of the middle frequency band is small, and the power fluctuation of the frequency bands on both sides is still large. Therefore, it is necessary to further perform compensation on L2 based on the second compensation value to obtain the power spectrum indicated by L3, so that the power spectrum tilts of the compensated first optical signal and the second optical signal also match, and the power spectrum of the first optical signal can be more accurately compensated. It should be understood that the second compensation value can also be zero if the first optical signal is a single wavelength signal.

[0068] Below, the calculation methods of the first compensation value and the second compensation value will be described separately.

[0069] The first compensation value may be calculated according to the following first formula, and a detailed description is provided below.

[0070] The first equation is

[0071]

number

[0072] where C1 represents the first compensation value, i represents the sequence number of the frequency band, M represents the quantity of the frequency band, Si1 represents the power fluctuation of the frequency band i in the second optical signal, Si2 represents the power fluctuation of the frequency band i in the first optical signal, and Xi represents the percentage of the optical power of the frequency band i in the first optical signal to the total power of the first optical signal. It should be understood that Si1 and Si2 can be obtained by the calculation of step 203. Furthermore, the difference between the power fluctuation of each band before adding or dropping a wavelength and the power fluctuation of each band after adding or dropping a wavelength is calculated, and then the difference and the power weight value of each band are multiplied to obtain a result, and the results of all bands are summed to obtain the first compensation value.

[0073] The second compensation value may be calculated according to the following second formula, a detailed description of which is provided below.

[0074] The second formula is C2=(S1max-S1min)-(S2max-S2min). C2 represents the second compensation value, S1max represents the optical power fluctuation of the frequency band of the last segment in the first optical signal, S1min represents the optical power fluctuation of the frequency band of the first segment in the first optical signal, S2max represents the optical power fluctuation of the frequency band of the last segment in the second optical signal, and S2min represents the optical power fluctuation of the frequency band of the first segment in the second optical signal. It should be understood that (S1max-S1min) represents the amount of power tilt of the first optical signal affected by the SRS effect, and (S2max-S2min) represents the amount of power tilt of the second optical signal affected by the SRS effect. The difference between the two is the power tilt fluctuation caused by the add / drop of the wavelength.

[0075] It should be noted that the waveband of the first segment in the first optical signal refers to the waveband with the smallest wavelength in the first optical signal, and the waveband of the last segment in the first optical signal refers to the waveband with the largest wavelength in the first optical signal. The waveband of the first segment in the second optical signal refers to the waveband with the smallest wavelength in the second optical signal, and the waveband of the last segment in the second optical signal refers to the waveband with the largest wavelength in the second optical signal. For example, the second optical signal is distributed from waveband 1 to waveband 10, and the waveband of the first segment and the waveband of the last segment of the second optical signal are waveband 1 and waveband 10, respectively. After performing wavelength dropping on the second optical signal, the first optical signal is distributed to waveband 2, waveband 5, and waveband 7, and the waveband of the first segment and the waveband of the last segment of the first optical signal are waveband 2 and waveband 7, respectively.

[0076] 205: Compensate a total power of the first optical signal based on a first compensation value, and compensate a power spectral tilt of the first optical signal based on a second compensation value.

[0077] Fig. 8 is a schematic diagram of the structure of an optical amplifier according to an embodiment of the present application. In particular, the optical amplifier can be adjusted to compensate for total power and power spectrum tilt. The following provides further explanation with reference to Fig. 8.

[0078] In the first case, if the first compensation value is a positive value, the currents of pump 1 and pump 2 inside the optical amplifier need to be increased so that the gain of the first optical signal, which is the gain of the first optical signal and is used after the first optical signal passes through the optical amplifier, increases by a value corresponding to the first compensation value. If the first compensation value is a negative value, the currents of pump 1 and pump 2 inside the optical amplifier need to be decreased so that the gain of the first optical signal, which is the gain of the first optical signal and is used after the first optical signal passes through the optical amplifier, decreases by a value corresponding to the first compensation value. For example, if the total power of the first optical signal before power compensation is 18 dBm and the first compensation value is 1 dB, the total power of the first optical signal after power compensation is 19 dBm.

[0079] In the second case, if the second compensation value is a positive value, the attenuation of the variable optical attenuator (VOA) between pump 1 and pump 2 needs to be increased so that the gain slope of the first optical signal, which is used after the first optical signal has passed through the optical amplifier, is increased by a value corresponding to the second compensation value. If the second compensation value is a negative value, the attenuation of the VOA between pump 1 and pump 2 needs to be decreased so that the gain slope of the first optical signal, which is used after the first optical signal has passed through the optical amplifier, is decreased by a value corresponding to the second compensation value.

[0080] In an embodiment of the present application, the first optical signal is an optical signal obtained by adding or dropping a wavelength to the second optical signal, and the signal transmitting end needs to detect the first optical power of each frequency band in the first optical signal and the second optical power of each frequency band in the second optical signal. Then, after the first optical signal is transmitted from the transmitting end to the receiving end, the first optical power fluctuation caused by the SRS effect in each frequency band may be calculated based on the first optical power, and after the second optical signal is transmitted from the transmitting end to the receiving end, the second optical power fluctuation caused by the SRS effect in each frequency band may be calculated based on the second optical power. Then, the first compensation value and the second compensation value may be determined based on the first optical power fluctuation and the second optical power fluctuation. Furthermore, before the first optical signal is transmitted, the total power of the first optical signal may be compensated based on the first compensation value, so as to ensure that the power change caused by the SRS effect in the process of transmitting the first optical signal in the optical fiber does not exceed the system tolerance capability, thereby improving the stability of the signal transmission. Furthermore, the power spectral tilt of the first optical signal may be further compensated based on the second compensation value, so that the power spectral tilts of the first optical signal and the second optical signal received by the signal receiving end are consistent, thereby further improving the stability of signal transmission.

[0081] The above describes the method for determining a power compensation value of an optical signal in an embodiment of the present application, and the following describes the power calculation device in an embodiment of the present application.

[0082] Fig. 9 is a schematic diagram of the structure of a power calculation device. The power calculation device includes a processor 901, a memory 902, and a light detection module 903. The processor 901, the memory 902, and the light detection module 903 are connected to each other via lines. The memory 902 is configured to store program instructions and data. It should be noted that the power calculation device may be a power calculation device that implements the method for determining the power compensation value of the optical signal in the above-mentioned embodiment shown in Fig. 2.

[0083] In a possible implementation, the memory 902 stores program instructions and data (e.g., the first and second coefficients described in step 203 above) supporting the steps shown in Fig. 2. The processor 901 and the light detection module 903 are configured to perform the steps of the method shown in Fig. 2. In particular, the light detection module 903 is configured to perform steps 201 and 202 shown in Fig. 2. The processor 901 is configured to perform steps 203 to 205 shown in Fig. 2.

[0084] It should be understood that the light detection module 903 may be divided into a filter 401, a PD (402), and a data acquisition section 403, as shown in Fig. 4. Alternatively, the light detection module 903 may be divided into a spectrum detection section 501 and a data acquisition section 502, as shown in Fig. 5.

[0085] FIG. 10 is a schematic diagram of the structure of an optical transmission system according to an embodiment of the present application. The optical transmission system includes a first site 1001 and a second site 1002. The optical signal output by the first site 1001 is transmitted to the second site 1002 through an optical fiber. Specifically, the first site 1001 is configured to perform any method steps in the embodiment shown in FIG. 2. Before the optical signal output by the first site 1001 is coupled to the optical fiber, a first compensation value and a second compensation value may be pre-calculated and used to compensate for the total power fluctuation and the change amount of the power spectrum tilt of the optical signal, respectively. It should be understood that the first site may be an optical amplifier site, a ROADM site, etc. This is not particularly limited in this specification.

[0086] Those skilled in the art may understand that all or part of the steps in the above-mentioned embodiments may be implemented by hardware or a program instructing related hardware. The program may be stored in a computer-readable storage medium. The storage medium may be a read-only memory, a random access memory, etc. Specifically, for example, the above-mentioned processing unit or processor may be a central processing unit, a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or another programmable logic device, a transistor logic device, a hardware component, or any combination thereof. Whether the functions are performed by hardware or software depends on the design constraints of a specific application and technical solution. Those skilled in the art may use different methods to implement the functions described for each specific application, but the implementation should not be considered to go beyond the scope of the embodiments of the present application.

[0087] When implementing the embodiments using software, all or some of the steps of the method in the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded into a computer and executed, the procedures or functions according to the embodiments of the present application are generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or another programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from a computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center in a wired (e.g., coaxial cable, optical fiber, or digital subscriber line (DSL)) or wireless (e.g., infrared, radio, or microwave) manner. The computer-readable storage medium may be any available medium accessible by a computer, or a data storage device, such as a server or data center that integrates one or more available media. The usable medium may be a magnetic medium (e.g., a floppy disk, a hard disk, or a magnetic tape), an optical medium (e.g., a DVD), a semiconductor medium (e.g., a Solid-State Drive (SSD)), or the like.

[0088] Finally, please note that the above description is only a specific implementation of the present application, but is not intended to limit the scope of protection of the present application. Any variations or replacements that are easily understood by those skilled in the art within the technical scope disclosed in the present application shall be included in the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the scope of protection of the claims.

Claims

1. 1. A method for determining a power compensation value for an optical signal, comprising the steps of: obtaining a first optical signal and a second optical signal, the first optical signal being an optical signal obtained by adding or dropping a wavelength to the second optical signal, the second optical signal including at least one wavelength signal, the at least one wavelength signal of the second optical signal being dispersed into at least one frequency band, the first optical signal including at least one wavelength signal, the at least one wavelength signal of the first optical signal being dispersed into at least one frequency band, the wavelength signal of the first optical signal being dispersed into any frequency band corresponding to the first optical signal, and the wavelength signal of the second optical signal being dispersed into any frequency band corresponding to the second optical signal; detecting a first optical power of each frequency band in the first optical signal and a second optical power of each frequency band in the second optical signal; determining, based on the first optical power, a first optical power fluctuation in each frequency band corresponding to the first optical signal, which is caused during the transmission of the first optical signal from the transmitting end to the receiving end and used after the first optical signal is transmitted from the transmitting end to the receiving end; and determining, based on the second optical power, a second optical power fluctuation in each frequency band corresponding to the second optical signal, which is caused during the transmission of the second optical signal from the receiving end to the transmitting end and used after the second optical signal is transmitted from the receiving end to the transmitting end; determining a first compensation value based on the first optical power fluctuation and the second optical power fluctuation, the first compensation value being used to compensate a total power of the first optical signal; determining a second compensation value based on the first optical power fluctuation and the second optical power fluctuation, the second compensation value being used to compensate for a power spectral tilt of the first optical signal; A method comprising:

2. obtaining a first coefficient and a second coefficient, the first coefficient being associated with a transmission type of a signal and the second coefficient being associated with an optical power transmission for each of two wavebands; The step of determining, based on the first optical power, a first optical power fluctuation of each frequency band of the first optical signal, which is caused during the first optical signal transmission from a transmitting end to a receiving end and is used after the first optical signal is transmitted from the transmitting end to the receiving end, comprises: calculating the first optical power fluctuation based on the first optical power, the first coefficient, and the second coefficient; The step of determining, based on the second optical power, a second optical power fluctuation of each frequency band of the second optical signal, which is caused during the second optical signal transmission from the receiving end to the transmitting end and is used after the second optical signal is transmitted from the receiving end to the transmitting end, comprises: The method of claim 1 , comprising calculating the second optical power fluctuation based on the second optical power, the first factor, and the second factor.

3. The method comprises: obtaining a ratio of a first optical power of each waveband in the first optical signal to the total power of the first optical signal; determining a first compensation value based on the first optical power fluctuation and the second optical power fluctuation, calculating the first compensation value by substituting the first optical power fluctuation, the second optical power fluctuation, and the ratio into a first equation, The first formula is: [0010] wherein C1 represents the first compensation value, i represents a sequence number of a frequency band, M represents a quantity of frequency bands, Si1 represents a second optical power fluctuation of frequency band i in the second optical signal, Si2 represents a first optical power fluctuation of frequency band i in the first optical signal, and Xi represents the ratio.

4. determining a second compensation value based on the first optical power fluctuation and the second optical power fluctuation, calculating the second compensation value by substituting a first optical power fluctuation in a first segment waveband of the first optical signal, a first optical power fluctuation in a last segment waveband of the first optical signal, a second optical power fluctuation in the first segment waveband of the second optical signal, and a second optical power fluctuation in the last segment waveband of the second optical signal into a second equation, The method according to any one of claims 1 to 3, wherein the second equation comprises C2 = (S1max - S1min) - (S2max - S2min), C2 represents the second compensation value, S1max represents the first optical power fluctuation of the waveband of the last segment of the first optical signal, S1min represents the first optical power fluctuation of the waveband of the first segment of the first optical signal, S2max represents the second optical power fluctuation of the waveband of the last segment of the second optical signal, and S2min represents the second optical power fluctuation of the waveband of the first segment of the second optical signal.

5. The method comprises: compensating the total power of the first optical signal based on the first compensation value; compensating the power spectral tilt of the first optical signal based on the second compensation value; The method of claim 1 , further comprising:

6. The step of compensating the total power of the first optical signal based on the first compensation value comprises:

6. The method of claim 5, further comprising adjusting a pump current in an optical amplifier based on the first compensation value to adjust an output power of the first optical signal after the first optical signal passes through the optical amplifier.

7. The step of compensating for the power spectral tilt of the first optical signal based on the second compensation value comprises:

7. The method of claim 5 or 6, comprising adjusting an attenuation of a variable optical attenuator (VOA) in an optical amplifier based on the second compensation value to adjust a power spectral tilt of the first optical signal that is used after the first optical signal has passed through the optical amplifier.

8. The step of detecting a first optical power of each waveband in the first optical signal comprises: splitting the first optical signal into optical signals of a plurality of frequency bands via a filter; detecting the first optical power of each waveband in the first optical signal via a power detector; Including, The step of detecting a second optical power of each waveband in the second optical signal comprises: splitting the second optical signal into optical signals of a plurality of frequency bands via a filter; detecting the second optical power of each waveband in the second optical signal via a power detector; The method of any one of claims 1 to 7, comprising:

9. The step of detecting a first optical power of each waveband in the first optical signal comprises: detecting the first optical power of each wavelength in the first optical signal via an optical spectrum analyzer (OSA) or an optical performance monitor (OPM); The step of detecting a second optical power of each waveband in the second optical signal comprises:

8. The method of claim 1, further comprising detecting the second optical power of each wavelength in the second optical signal via the optical spectrum analyzer (OSA) or the optical performance monitor (OPM).

10. A power calculation device comprising a processor, a memory, and a light detection module, the processor, the memory, and the light detection module being connected to each other via a line, The light detection module includes: Obtaining a first optical signal and a second optical signal, the first optical signal being an optical signal obtained by adding or dropping a wavelength to the second optical signal, the second optical signal including at least one wavelength signal, the at least one wavelength signal of the second optical signal being dispersed into at least one frequency band, the first optical signal including at least one wavelength signal, the at least one wavelength signal of the first optical signal being dispersed into the at least one frequency band, the wavelength signal of the first optical signal being dispersed into any frequency band corresponding to the first optical signal, and the wavelength signal of the second optical signal being dispersed into any frequency band corresponding to the second optical signal; Detecting a first optical power of each frequency band in the first optical signal and a second optical power of each frequency band in the second optical signal. It is configured as follows: The processor, determining, based on the first optical power, a first optical power fluctuation in each frequency band corresponding to the first optical signal, which is caused during the transmission of the first optical signal from the transmitting end to the receiving end and used after the first optical signal is transmitted from the transmitting end to the receiving end; determining, based on the second optical power, a second optical power fluctuation in each frequency band corresponding to the second optical signal, which is caused during the transmission of the second optical signal from the receiving end to the transmitting end and used after the second optical signal is transmitted from the receiving end to the transmitting end; determining a first compensation value based on the first optical power fluctuation and the second optical power fluctuation, the first compensation value being used to compensate a total power of the first optical signal; determining a second compensation value based on the first optical power fluctuation and the second optical power fluctuation, the second compensation value being used to compensate for a power spectral tilt of the first optical signal; A power calculation device configured to:

11. The processor, The method is further configured to obtain a first coefficient and a second coefficient, the first coefficient being associated with a transmission type of the signal and the second coefficient being associated with an optical power transfer for each of the two wavebands; The processor, calculating the first optical power fluctuation based on the first optical power, the first coefficient, and the second coefficient; The power calculation unit of claim 10 configured to calculate the second optical power variation based on the second optical power, the first coefficient, and the second coefficient.

12. The processor, further configured to obtain a ratio of an optical power of each waveband in the first optical signal to the total power of the first optical signal; The processor, configured to calculate the first compensation value by substituting the first optical power fluctuation, the second optical power fluctuation, and the ratio into a first equation; The first formula is: [0025] 12. The power calculation device of claim 10, further comprising: C1 represents the first compensation value, i represents a sequence number of a frequency band, M represents a quantity of frequency bands, Si1 represents a second optical power fluctuation of frequency band i in the second optical signal, Si2 represents a first optical power fluctuation of frequency band i in the first optical signal, and Xi represents the ratio.

13. The processor, is configured to calculate the second compensation value by substituting a first optical power fluctuation in a first segment waveband of the first optical signal, a first optical power fluctuation in a last segment waveband of the first optical signal, a second optical power fluctuation in the first segment waveband of the second optical signal, and a second optical power fluctuation in the last segment waveband of the second optical signal into a second equation; The second equation includes C2=(S1max-S1min)-(S2max-S2min), 13. The power calculation device according to claim 10, wherein C2 represents the second compensation value, S1max represents the first optical power fluctuation of the waveband of the final segment in the first optical signal, S1min represents the first optical power fluctuation of the waveband of the first segment in the first optical signal, S2max represents the second optical power fluctuation of the waveband of the final segment in the second optical signal, and S2min represents the second optical power fluctuation of the waveband of the first segment in the second optical signal.

14. The processor, Compensating the total power of the first optical signal based on the first compensation value; 14. The power calculation apparatus of claim 10, further configured to compensate the power spectral tilt of the first optical signal based on the second compensation value.

15. The processor, 15. The power calculation apparatus of claim 14, configured to adjust a pump current in an optical amplifier based on the first compensation value to adjust an output power of the first optical signal after the first optical signal passes through the optical amplifier.

16. The processor, 16. The power calculation apparatus of claim 14 or 15, configured to adjust an attenuation of a variable optical attenuator (VOA) in an optical amplifier based on the second compensation value to adjust a power spectral tilt of the first optical signal that is used after the first optical signal has passed through the optical amplifier.

17. the optical detection module includes a filter and a power detector; The filter comprises: Splitting the first optical signal into optical signals of a plurality of frequency bands; configured to split the second optical signal into optical signals in a plurality of frequency bands; The power detector comprises: Detecting the first optical power of each waveband in the first optical signal; 17. A power calculation apparatus according to any one of claims 10 to 16, configured to detect the second optical power in each waveband in the second optical signal.

18. The optical detection module includes an optical spectrum analyzer (OSA) or an optical performance monitor (OPM); The OSA or the OPM is Detecting the first optical power for each wavelength in the first optical signal; 17. A power calculation apparatus according to any one of claims 10 to 16, configured to detect the second optical power for each wavelength in the second optical signal.

19. 10. An optical transmission system comprising a first site and a second site, the first site configured to perform a method for determining a power compensation value of an optical signal according to any one of claims 1 to 9, and the second site configured to receive an optical signal output by the first site.

20. 20. The optical transmission system of claim 19, wherein the first site comprises an optical amplifier site or a reconfigurable optical add / drop multiplexer (ROADM) site.

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