Optical detection device, optical transmitter, detection method and communication method

Abstract

The embodiment of the invention provides optical detection equipment, an optical transmitter, a detection method and a communication method, which are applied to the technical field of optical communication. The optical detection device is used for receiving a first optical signal, the first optical signal comprises an optical signal of at least one channel, the optical signal of each channel carries at least one pilot signal, different pilot signals are carried on the optical signals of different spectral ranges of the corresponding channels, the pilot signals have different phases, and the first optical signal is used for receiving the first optical signal; the same pilot signal of different phases is carried on different spectral partitions of the corresponding spectral range of the optical signal. The sum of the power of at least one pilot signal of the same channel is smaller than a certain threshold value. And according to the first optical signal, obtaining the optical power of the optical signal in the spectral range where the at least one pilot signal is located. According to the embodiment of the invention, the SRS crosstalk problem of pilot signal transmission is avoided when optical communication performance detection is carried out based on the pilot signal.

Description

Technical Field

[0001] This application relates to the field of optical communication technologies, and in particular, to an optical detection device, an optical transmitter, a detection method, and a communication method. Background Art

[0002] In the field of optical communication technologies, multiple network nodes are constructed, and the multiple network nodes form an optical communication system based on optical fibers to perform optical communication. When performing optical communication, one or more network nodes can modulate service information on service optical signals of different channels by corresponding optical transmitters, and transmit and transport the service optical signals through optical fibers. Similarly, a network node can also receive corresponding service optical signals from the optical fiber and parse to obtain corresponding service information to complete the reception of the service information. Usually, in order to ensure normal optical communication between multiple network nodes, it is necessary to detect the optical communication performance of each channel, etc.

[0003] An existing detection method is as follows: optical signals are divided into different channels according to the spectral range, and the transmitter can perform communication work based on one or more channels. Different spectral ranges are divided in each channel. Pilot signals of different frequencies are modulated on optical signals in different spectral ranges. One or more optical detection devices are arranged in the optical communication system. Each optical detection device can obtain pilot signals of different spectral ranges from the optical fiber to detect the optical communication performance of each channel, etc. However, in actual applications, affected by the stimulated Raman scattering (SRS) effect during optical fiber transmission, crosstalk occurs between pilot signals of different frequencies in multiple channels, thereby affecting the detection accuracy of the optical communication performance. Summary of the Invention

[0004] Embodiments of this application provide an optical detection device, an optical transmitter, a detection method, and a communication method, which improve the detection accuracy of optical communication performance.

[0005] To achieve the above object, the embodiments of this application adopt the following technical solutions:

[0006] In a first aspect, an optical detection device is provided, which includes a filter and a signal processing structure. Specifically: The filter is configured to: receive a first optical signal, where the first optical signal includes optical signals of at least one channel, and each channel's optical signal carries at least one pilot signal. Different pilot signals correspond to different spectral ranges within the channel, the pilot signals have different phases, and the same pilot signal with different phases corresponds to different spectral partitions within the spectral range. The sum of the powers of at least one pilot signal in the same channel is less than a certain threshold. Filter the first optical signal to obtain at least one filtered optical signal, and at least one filtered optical signal carries at least one pilot signal. The signal processing structure is configured to: obtain the optical power of the optical signal within the spectral range where at least one pilot signal is located based on the at least one filtered optical signal.

[0007] In the embodiments of the present application, by corresponding different spectral partitions of the optical signal of one channel with the same pilot signal in the form of different phases, power cancellation can be performed during the transmission between the same pilot signal with different phases, so that the sum of the powers of the same pilot signal in multiple phases is less than a certain threshold, thereby ensuring that the sum of the powers of at least one pilot signal in the same channel is less than a certain threshold. Among them, in an ideal state, power cancellation can be achieved during the transmission between the same pilot signal with different phases, so that the sum of the powers of the same pilot signal is zero. Limited by processing errors on the transmitting side, transmission errors in optical fiber transmission, and detection errors during detection, etc., the actual detected value of the sum of the powers of the same pilot signal may not be zero. Therefore, in practical applications, as long as it is ensured that the sum of the powers of at least one pilot signal in the same channel is less than a certain threshold, it is possible to avoid the problem of SRS power crosstalk between the pilot signals of different channels carried on the optical signal, so as to improve the transmission accuracy of the pilot signal. This threshold can be a detection threshold affected by the above-mentioned processing errors, transmission errors, and detection errors, or a preset certain threshold. At the optical detection device, based on the filter, the same pilot signal with different phases in the optical signal of the corresponding channel can be filtered and separated to realize the normal reception and processing of the pilot signal, and the optical power can be detected based on the pilot signal. Optical power is a basic parameter for detecting optical communication performance. Therefore, accurate detection of optical communication performance can be achieved based on the above method.

[0008] In a possible implementation, half of the spectral period length of the filter is greater than or equal to the regional length of the spectral partition. The signal processing structure includes a first photodetector, a second photodetector, and a data processor. Among them: The filter is used for: filtering the first optical signal to obtain at least one filtered optical signal, and the at least one filtered optical signal includes a first filtered optical signal and a second filtered optical signal. The first filtered optical signal and the second filtered optical signal are consistent with the spectral range division of the optical signals of at least one channel. The first photodetector is used for: performing photoelectric conversion on the first filtered optical signal to obtain a first filtered electrical signal. The second photodetector is used for: performing photoelectric conversion on the second filtered optical signal to obtain a second filtered electrical signal. The data processor is specifically used for: obtaining the optical power of the optical signal within the spectral range where at least one pilot signal is located according to the first filtered electrical signal and the second filtered electrical signal. In the embodiments of the present application, filtering processing can be performed based on the filter to separate the same pilot signal with different phases onto different filtered optical signals (for example, separating the pilot signals with different phases onto the first filtered optical signal and the second filtered optical signal). By performing photoelectric processing on at least one filtered optical signal respectively, corresponding filtered electrical signals are obtained. The data processor can detect the optical communication performance based on the filtered electrical signals, such as detecting the optical power, etc.

[0009] In a possible implementation, the at least one filtered optical signal includes a first filtered optical signal and a second filtered optical signal; the at least one pilot signal includes a first pilot signal, the first filtered optical signal carries the first pilot signal with a first phase, and the second filtered optical signal carries the first pilot signal with a second phase; the first phase and the second phase differ by 180°. In the embodiments of the present application, for the same pilot signal, two different phases can be set, and the two phases are opposite to each other (that is, the phase difference is 180°). Based on the two phases that are opposite to each other, the power of the same pilot signal during transmission can be better adjusted (that is, power cancellation can be achieved between the phases that are opposite during transmission), so that the sum of its power remains zero within the threshold range over time during transmission, thereby avoiding the crosstalk problem of the pilot signals between multiple channels.

[0010] In a possible implementation, according to different application scenarios and actual requirements, filters with different period lengths can be selected for the filtering and separation processing of pilot signals to match channels with different code patterns. At the same time, the pilot signals can also be modulated in different ways. The following takes several typical situations as examples for illustration:

[0011] In some examples, the same pilot signal with different phases can be corresponding to fixed spectral partitions.

[0012] In some examples, the same pilot signal with different phases corresponds to different spectral partitions, and at different time slots, the same pilot signal with the same phase corresponds to different spectral partitions. At this time, at least one pilot signal further includes a second pilot signal. In the first time slot, the second pilot signal with the first phase is carried on the first filtered optical signal, and the second pilot signal with the second phase is carried on the second filtered optical signal. In the second time slot, the second pilot signal with the second phase is carried on the first filtered optical signal, and the second pilot signal with the first phase is carried on the second filtered optical signal, and the first time slot and the second time slot alternate with each other. In the embodiments of the present application, pilot signals with different phases can also be modulated on the optical signal at different time slots to make the sum of the powers of at least one pilot signal in the same channel less than a certain threshold.

[0013] Exemplarily, the spectral range division of the first filtered optical signal and the second filtered optical signal is consistent with the spectral range division of the optical signal of at least one channel. The quarter-period length of the filter is equal to the regional length of the spectral partition. On the optical signal of the corresponding channel, there is a second spectral partition between the second pilot signal with the first phase and the second pilot signal with the second phase. In the first time slot, the second pilot signal with the first phase corresponds to the first spectral partition of the first filtered optical signal, and the second pilot signal with the second phase corresponds to the third spectral partition of the second filtered optical signal. The first spectral partition, the second spectral partition, and the third spectral partition are three adjacent spectral partitions in sequence. In the second time slot, the second pilot signal with the second phase corresponds to the first spectral partition of the first filtered optical signal, and the second pilot signal with the first phase corresponds to the third spectral partition of the second filtered optical signal. In the embodiments of the present application, according to different code patterns, a second spectral partition can be set between the pilot signals of the two phases, and based on the second spectral partition and the third spectral partition carrying the second pilot signal with the second phase, an output signal spectrum with a half-period length of the filter can be formed. Thus, the second pilot signal with the first phase and the second pilot signal with the second phase are filtered and separated onto different filtered optical signals.

[0014] Exemplarily, a reference pilot signal is further carried on the optical signal of the corresponding channel. The reference pilot signal corresponds to the second spectral partition of the second filtered optical signal, and the frequency of the reference pilot signal is different from that of at least one pilot signal. The data processor is further configured to: obtain the stimulated Raman scattering crosstalk degree of the second pilot signal according to the first filtered electrical signal and the second filtered electrical signal. In the embodiments of the present application, signal processing can be performed based on the reference pilot signal and the second pilot signal to detect the stimulated Raman scattering crosstalk degree of the second pilot signal.

[0015] Exemplarily, the spectral range division of the first filtered optical signal and the second filtered optical signal is consistent with the spectral range division of the optical signal of the at least one channel. The quarter-period length of the filter is equal to the partition length of the spectral partition. At the first time slot, the second pilot signal with the first phase corresponds to the first spectral partition of the first filtered optical signal, and the second pilot signal with the second phase corresponds to the second spectral partition of the second filtered optical signal. At the second time slot, the second pilot signal with the second phase corresponds to the first spectral partition of the first filtered optical signal, and the second pilot signal with the first phase corresponds to the second spectral partition of the second filtered optical signal. There is no corresponding pilot signal on the third spectral partition of the second filtered optical signal, and the first spectral partition, the second spectral partition, and the third spectral partition are three adjacent spectral partitions in sequence. In the embodiment of the present application, the first spectral partition and the second spectral partition can be set on the output signal spectra of two different half-period lengths of the filter, so as to filter and separate the second pilot signal with the first phase and the second pilot signal with the second phase onto different filtered optical signals.

[0016] Exemplarily, the spectral range division of the first filtered optical signal and the second filtered optical signal is consistent with the spectral range division of the optical signal of the at least one channel. The quarter-period length of the filter is equal to the partition length of the spectral partition. At the first time slot, the second pilot signal with the first phase corresponds to the first spectral partition of the first filtered optical signal, and the second pilot signal with the second phase corresponds to the sum of the second spectral partition and the third spectral partition of the second filtered optical signal; the first spectral partition, the second spectral partition, and the third spectral partition are three adjacent spectral partitions in sequence. At the second time slot, the second pilot signal with the second phase corresponds to the first spectral partition of the first filtered optical signal, and the second pilot signal with the first phase corresponds to the second spectral partition and the third spectral partition of the second filtered optical signal. The modulation signal amplitudes of the second pilot signals corresponding to the second spectral partition and the third spectral partition are respectively half of the modulation signal amplitude of the second pilot signal corresponding to the first spectral partition. In the embodiment of the present application, based on the second spectral partition and the third spectral partition, an output signal spectrum of a half-period length of the filter can be formed. Thus, the second pilot signal with the first phase and the second pilot signal with the second phase are filtered and separated onto different filtered optical signals. However, since the second pilot signals with the same phase are carried on both the second spectral partition and the third spectral partition, in order to ensure the power cancellation between the second pilot signals on the second spectral partition and the third spectral partition and the second pilot signal on the first spectral partition, the signal amplitudes (i.e., modulation signal amplitudes) of the second pilot signals on the second spectral partition and the third spectral partition can be halved.

[0017] In some possible embodiments, at least one filtered optical signal includes a first filtered optical signal and a second filtered optical signal. The spectral range division of the first filtered optical signal and the second filtered optical signal is consistent with the spectral range division of the optical signals of the at least one channel. The quarter-period length of the filter is equal to the partition length of the spectral partition. At least one pilot signal includes a third pilot signal. At the first time slot, the third pilot signal with the third phase corresponds to the second spectral partition of the first filtered optical signal, and the third pilot signal with the fourth phase corresponds to the third spectral partition of the second filtered optical signal. There is a 120° phase difference between the third phase and the fourth phase. At the second time slot, the third pilot signal with the third phase corresponds to the first spectral partition of the first filtered optical signal, and the third pilot signal with the fourth phase corresponds to the second spectral partition of the second filtered optical signal. The first spectral partition, the second spectral partition, and the third spectral partition are three adjacent spectral partitions in sequence. In the embodiments of the present application, it is also possible to, under time-division-based modulation, in a manner that the third pilot signals with the third phase and the fourth phase with a phase difference of 120° are misaligned within the spectral range at different time slots, so as to make the sum of the powers of at least one pilot signal of the same channel less than a certain threshold, thereby avoiding the SRS crosstalk problem.

[0018] In a possible embodiment, the optical signals of at least one channel have different polarization states, and different pilot signals are carried on the optical signals with different polarization states. The signal processing structure is further configured to: obtain the polarization-dependent loss of the optical signals of at least one channel according to at least one filtered optical signal. In the embodiments of the present application, the optical signal can be an optical signal that realizes modulation based on different polarization states. At this time, different pilot signals can be set for the optical signals with different polarization states. The detection of the polarization-dependent loss can be realized according to the optical power of the pilot signals corresponding to different polarization states, etc.

[0019] In some possible embodiments, the signal processing structure is further configured to: obtain the filtering processing ability regarding the channel according to at least one filtered optical signal. In the embodiments of the present application, the high or low filtering processing ability of the wavelength signal can also be determined according to the insertion loss ratio between the pilot signals with different phases within each channel.

[0020] In some possible embodiments, the filter is a comb filter. In some examples, according to the different actual output numbers, the filter can be a comb filter with one output, two outputs or more outputs. Exemplarily, the filter can form a comb filter by adopting different device structures. For example, based on Mach-Zehnder interferometer, Michelson interferometer, and interferometer based on arrayed waveguide grating, etc. And, the center frequency points of the transmittance spectrum of the comb filter can be equally spaced or unequally spaced, and its transmittance spectrum width can also be different. In the embodiments of the present application, the filter can filter and separate optical signals in different spectral ranges, and one separated part corresponds to one filtered optical signal. The filter can filter and output only the optical signals in a part of the spectral ranges among all the spectral ranges, or can filter and output the optical signals in multiple partial spectral ranges among all the spectral ranges respectively. The optical signals in the spectral range of the filtered output can be used as one output filtered optical signal, or the optical signals in multiple spectral ranges of the filtered output can be used as multiple output filtered optical signals respectively.

[0021] In some possible embodiments, the duty cycle of the output of the filter is at least one of the following: 12.5%, 25%, 50%, 75%, 87.5%. In the embodiments of the present application, the above takes the duty cycle of the output of the filter being 50% as an example. However, in actual applications, other output duty cycles can also be selected according to application requirements. Regarding the design idea under the selection of other output duty cycles, reference can be made to the relevant records of the foregoing embodiments, which will not be elaborated herein.

[0022] In a possible embodiment, the frequency of the pilot signal is at the level of several MHz. In the embodiments of the present application, after avoiding the interference of the SRS crosstalk problem during the transmission process, the requirement for the frequency of the pilot signal is reduced. In a commercial scenario, the frequency of the pilot signal can be reduced to the level of several MHz. After reducing the frequency of the pilot signal, problems such as fiber dispersion on the pilot signal can be reduced, and the transmission and processing accuracy of the pilot signal can be improved.

[0023] In a second aspect, the embodiments of the present application further provide an optical transmitter, which is used for: modulating a carrier optical signal to obtain an optical signal including one or more channels, each channel optical signal carries at least one pilot signal, different pilot signals correspond to different spectral ranges of the channel, the pilot signals have different phases, and the same pilot signal with different phases corresponds to different spectral partitions within the spectral range. The sum of the powers of at least one pilot signal in the same channel is less than a certain threshold. Transmitting the optical signal of one or more channels to the optical fiber.

[0024] In a possible implementation manner, modulating the carrier optical signal to obtain an optical signal including one or more channels includes: generating at least one pilot signal, where the at least one pilot signal includes a first pilot signal, and the first pilot signal has a first phase and a second phase, and the first phase and the second phase differ by 180°. Modulating the first pilot signal onto the carrier optical signal to obtain the optical signal of the corresponding channel, and the first pilot signals with the first phase and the second phase correspond to different spectral partitions within the corresponding spectral range.

[0025] In a possible implementation manner, modulating the carrier optical signal to obtain an optical signal including one or more channels includes: generating at least one pilot signal, where the at least one pilot signal includes a second pilot signal, and the second pilot signal has a first phase and a second phase, and the first phase and the second phase differ by 180°. Modulating the second pilot signals with different phases onto the carrier optical signal to obtain the optical signals of the corresponding channels. At the first time slot and the second time slot, the second pilot signals with the same phase correspond to different spectral partitions within the corresponding spectral range, and the first time slot and the second time slot alternate with each other.

[0026] In a possible implementation manner, on the optical signal of the corresponding channel, there is a second spectral partition between the second pilot signal with the first phase and the second pilot signal with the second phase. Modulating the carrier optical signal to obtain an optical signal including one or more channels further includes: carrying a reference pilot signal on the optical signal of the corresponding channel, the reference pilot signal corresponds to the second spectral partition, and the frequency of the reference pilot signal is different from that of the at least one pilot signal.

[0027] In a possible implementation manner, modulating the carrier optical signal to obtain an optical signal including one or more channels includes: generating at least one pilot signal, where the at least one pilot signal includes a third pilot signal, and the third pilot signal has a third phase and a fourth phase, and the third phase and the fourth phase differ by 180°. Modulating the third pilot signals with different phases onto the carrier optical signal to obtain the optical signals of the corresponding channels. At the first time slot, the third pilot signal with the third phase corresponds to the second spectral partition, and the third pilot signal with the fourth phase corresponds to the third spectral partition. At the second time slot, the third pilot signal with the third phase corresponds to the first spectral partition, and the third pilot signal with the fourth phase corresponds to the second spectral partition. The first time slot and the second time slot alternate with each other. The first spectral partition, the second spectral partition, and the third spectral partition are three adjacent spectral partitions in sequence.

[0028] In a possible implementation manner, modulating the carrier optical signal to obtain an optical signal including one or more channels further includes: modulating the carrier optical signal with different polarization states, and different pilot signals are carried on the optical signals with different polarization states.

[0029] In some possible embodiments, the frequency of the pilot signal is at the level of several MHz.

[0030] In a third aspect, an embodiment of the present application further provides a detection method. The detection method is based on an optical detection device, and the optical detection device includes a filter. The method includes: receiving a first optical signal, where the first optical signal includes optical signals of at least one channel, and each channel's optical signal carries at least one pilot signal. Different pilot signals correspond to optical signals in different spectral ranges within the channel. The pilot signals have different phases, and the same pilot signal with different phases corresponds to different spectral partitions within the spectral range. The sum of the powers of at least one pilot signal in the same channel is less than a certain threshold. Filtering the first optical signal to obtain at least one filtered optical signal, where at least one filtered optical signal carries at least one pilot signal. Obtaining the optical power of the optical signal within the spectral range where at least one pilot signal is located according to at least one filtered optical signal.

[0031] In a possible embodiment, at least one filtered optical signal includes a first filtered optical signal and a second filtered optical signal. The above filtering the first optical signal to obtain at least one filtered optical signal includes: filtering the first optical signal to obtain at least one filtered optical signal, where at least one filtered optical signal includes a first filtered optical signal and a second filtered optical signal; the first filtered optical signal and the second filtered optical signal are consistent with the spectral range division of the optical signals of at least one channel. The above obtaining the optical power of the optical signal within the spectral range where at least one pilot signal is located according to at least one filtered optical signal includes: performing photoelectric conversion on the first filtered optical signal to obtain a first filtered electrical signal; performing photoelectric conversion on the second filtered optical signal to obtain a second filtered electrical signal; obtaining the optical power of the optical signal within the spectral range where at least one pilot signal is located according to the first filtered electrical signal and the second filtered electrical signal.

[0032] In a possible embodiment, at least one filtered optical signal includes a first filtered optical signal and a second filtered optical signal; the spectral range division of the first filtered optical signal and the second filtered optical signal is consistent with the spectral range division of the optical signals of at least one channel. At least one pilot signal further includes a second pilot signal. On the optical signal of the corresponding channel, there is a second spectral partition between the second pilot signal with the first phase and the second pilot signal with the second phase. A reference pilot signal is also carried on the optical signal of the corresponding channel, and the reference pilot signal corresponds to the second spectral partition and has a different frequency from at least one pilot signal. The method further includes: obtaining the stimulated Raman scattering crosstalk degree of the second pilot signal according to the first filtered electrical signal and the second filtered electrical signal.

[0033] In a possible implementation, the optical signals of at least one channel have different polarization states, and different pilot signals are carried on the optical signals with different polarization states. The method further includes: obtaining the polarization-dependent loss of the optical signals of at least one channel according to at least one filtered optical signal.

[0034] In some possible implementations, the method further includes: obtaining the filtering processing capability of the channel according to at least one filtered optical signal.

[0035] In some possible implementations, the output duty cycle of the filter is at least one of the following: 12.5%, 25%, 50%, 75%, 87.5%.

[0036] In a possible implementation, the frequency of the pilot signal is at the level of several MHz.

[0037] In a fourth aspect, an embodiment of the present application further provides a communication method based on an optical transmitter. The method includes: modulating a carrier optical signal to obtain an optical signal including one or more channels, at least one pilot signal is carried on the optical signal of each channel, different pilot signals correspond to different spectral ranges within the channel, the pilot signals have different phases, and different spectral partitions within the spectral range correspond to the same pilot signal with different phases. The sum of the powers of at least one pilot signal in the same channel is less than a certain threshold. Transmitting the optical signal of one or more channels to an optical fiber.

[0038] In a possible implementation, modulating the carrier optical signal to obtain an optical signal including one or more channels includes: generating at least one pilot signal, the at least one pilot signal includes a first pilot signal, the first pilot signal has a first phase and a second phase, and the first phase and the second phase differ by 180°. Modulating the first pilot signal onto the carrier optical signal to obtain the optical signal of the corresponding channel, and different spectral partitions within the spectral range correspond to the first pilot signal with the first phase and the first pilot signal with the second phase.

[0039] In a possible implementation, modulating the carrier optical signal to obtain an optical signal including one or more channels includes: generating at least one pilot signal, the at least one pilot signal includes a second pilot signal, the second pilot signal has a first phase and a second phase, and the first phase and the second phase differ by 180°. In the first time slot and the second time slot, modulating the second pilot signal with the same phase into different spectral partitions of the corresponding carrier optical signal to obtain the optical signal of the corresponding channel, and the first time slot and the second time slot alternate with each other.

[0040] In a possible implementation manner, on the optical signal of the corresponding channel, there is a second spectral partition between the second pilot signal of the first phase and the second pilot signal of the second phase. Modulating the carrier optical signal to obtain an optical signal including one or more channels further includes: carrying a reference pilot signal on the optical signal of the corresponding channel, the reference pilot signal corresponding to the second spectral partition, and the reference pilot signal having a different frequency from at least one pilot signal.

[0041] In a possible implementation manner, modulating the carrier optical signal to obtain an optical signal including one or more channels includes: generating at least one pilot signal, the at least one pilot signal including a third pilot signal, the third pilot signal having a third phase and a fourth phase, and the third phase and the fourth phase differing by 180°. Modulating the third pilot signals with different phases onto the carrier optical signal to obtain the optical signal of the corresponding channel. In the first time slot, the third pilot signal of the third phase corresponds to the second spectral partition, and the third pilot signal of the fourth phase corresponds to the third spectral partition. In the second time slot, the third pilot signal of the third phase corresponds to the first spectral partition, and the third pilot signal of the fourth phase corresponds to the second spectral partition. The first time slot and the second time slot alternate with each other. The first spectral partition, the second spectral partition, and the third spectral partition are three adjacent spectral partitions in sequence.

[0042] In a possible implementation manner, modulating the carrier optical signal to obtain an optical signal including one or more channels further includes: modulating the carrier optical signal with different polarization states, and different pilot signals being carried on the optical signals with different polarization states.

[0043] In a fifth aspect, an embodiment of the present application further provides a computer-readable storage medium, the computer-readable storage medium including instructions that, when running on a data processor, cause the data processor to execute a detection method, the detection method including: obtaining the optical power of the optical signal within the spectral range where at least one pilot signal is located according to at least one filtered electrical signal. The at least one filtered electrical signal is obtained by photoelectric conversion of at least one filtered optical signal. The at least one filtered optical signal is obtained by filtering the optical signal of at least one channel. The at least one pilot signal is carried on the optical signal of the corresponding channel, and the pilot signal has different phases; the same pilot signal with different phases corresponds to different spectral partitions within the channel; at least one pilot signal is carried on the at least one filtered optical signal.

[0044] In a sixth aspect, an embodiment of the present application further provides an optical communication system, the optical communication system including at least one optical detection device as described in the first aspect above and a plurality of optical transmitters as described in the second aspect above. The optical transmitter and the optical detection device are respectively coupled to an optical fiber.

[0045] For the technical principles and beneficial effects of the above second, third, fourth, fifth, and sixth aspects, reference may be made to the relevant descriptions of the first aspect above, and details will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 FIG. 1 is a schematic structural diagram of an optical communication system provided by an embodiment of the present application;

[0047] Figure 2 FIG. 2 is a schematic diagram of the pilot - spectrum range distribution of carrying a pilot signal on an optical signal of a corresponding channel in the prior art;

[0048] Figure 3 FIG. 3 is a schematic diagram of SRS crosstalk generated by different pilot signals;

[0049] Figure 4 FIG. 4 is a schematic structural diagram of another optical communication system provided by an embodiment of the present application;

[0050] Figure 5 FIG. 5 is a schematic structural diagram of an optical detection device provided by an embodiment of the present application; Figure 1 ;

[0051] Figure 6 FIG. 6 is a schematic structural diagram of another optical detection device provided by an embodiment of the present application; Figure 2 ;

[0052] Figure 7 FIG. 7 is a schematic structural diagram of yet another optical detection device provided by an embodiment of the present application; Figure 3 ;

[0053] Figure 8 FIG. 8 is a schematic structural diagram of yet another optical detection device provided by an embodiment of the present application; Figure 4 ;

[0054] Figure 9 FIG. 9 is a schematic flowchart of a communication method provided by an embodiment of the present application;

[0055] Figure 10 FIG. 10 is a schematic diagram of carrying first - pilot signals of a first phase and a second phase on different spectral partitions of an optical signal of a corresponding channel in a frequency - division - based manner provided by an embodiment of the present application;

[0056] Figure 11 FIG. 11 is a schematic diagram of carrying second - pilot signals of a first phase and a second phase on different spectral partitions of an optical signal of a corresponding channel in a time - division - based manner provided by an embodiment of the present application;

[0057] Figure 12Schematic diagram of carrying third pilot signals of the third phase and the fourth phase on different spectral partitions of the optical signal of the corresponding channel in a time-division manner provided by an embodiment of the present application;

[0058] Figure 13 Schematic flow diagram of a detection method provided by an embodiment of the present application;

[0059] Figure 14 Schematic diagram of the output principle of a comb filter provided by an embodiment of the present application;

[0060] Figure 15 For an embodiment of the present application Figure 10 Schematic diagram of filtering the optical signal of the corresponding channel under the modulation mode shown;

[0061] Figure 16 For another embodiment of the present application Figure 10 Schematic diagram of filtering the optical signal of the corresponding channel under the modulation mode shown;

[0062] Figure 17 Schematic diagram of modulating the optical signal of the corresponding channel with a certain spectral interval between the same pilot signals of different phases provided by an embodiment of the present application;

[0063] Figure 18 For an embodiment of the present application Figure 11 Schematic diagram of filtering the optical signal of the corresponding channel under the modulation mode shown in FIG. (a). Detailed implementation manners

[0064] It should be noted that the terms "first", "second", etc. involved in the embodiments of the present application are only used for the purpose of distinguishing the same type of features, and cannot be understood as indicating relative importance, quantity, order, etc.

[0065] The terms "exemplary" or "for example" etc. involved in the embodiments of the present application are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or design solutions. Exactly speaking, the use of the terms "exemplary" or "for example" etc. aims to present the relevant concepts in a specific manner.

[0066] The terms "coupling" and "connection" involved in the embodiments of the present application should be understood in a broad sense. For example, it can refer to a direct physical connection, or an indirect connection realized through electronic devices, such as a connection realized through resistors, inductors, capacitors or other electronic devices.

[0067] First, some basic concepts involved in the embodiments of the present application are explained:

[0068] Dense Wavelength Division Multiplexing (DWDM) is a fiber-optic data transmission technology. This technology uses the wavelengths of lasers to transmit data in the optical fiber in either a bit-parallel or string-row transmission manner. DWDM is an important part of fiber-optic networks, allowing communication data based on different protocols and technologies to be transmitted through a unified optical fiber layer. Driven by the needs of emerging services and high-speed transmission of massive data, optical networks are becoming increasingly complex and extensive, and optical connections are becoming more dynamic and flexible. Therefore, it is urgent to adopt corresponding detection methods to ensure the stable and efficient operation of optical networks. Especially with the large-scale application of DWDM systems, in order to ensure the reliable operation of DWDM systems and reduce interruptions caused by network failures, it is crucial to simultaneously detect the optical channel performance of each DWDM wavelength channel by using a low-cost method.

[0069] An embodiment of this application provides an optical communication system, which may include multiple network nodes that are coupled through optical fibers. Among them, the multiple network nodes may include optical receivers and / or optical transmitters. Optical communication is realized based on optical receivers and optical transmitters. As Figure 1 shown, in the optical communication system 10000, multiple optical transmitters 1000 are coupled to an optical receiver 2000 through an optical fiber F. Each optical transmitter 1000 can modulate service information onto optical signals of different wavelengths, and the optical signals transmitted by different optical transmitters 1000 are combined on the optical fiber F to form a transmission optical signal for transmission. The optical receiver 2000 obtains the optical signal corresponding to the wavelength of the corresponding service from the optical fiber F and resolves the relevant service information from the optical signal. To ensure the orderly and normal communication of signals, the optical signals are usually divided into frequency bands according to the spectral range, and the optical signals are divided into multiple channels, with each channel corresponding to an optical signal within a certain spectral range. Different transmitters 1000 perform optical communication corresponding to different channels. One transmitter 1000 can perform optical communication based on one or more channels.

[0070] To ensure the communication quality, etc., of optical communication between multiple network nodes, as Figure 1 shown, an optical detection device 3000 is also provided in the optical communication system 10000. Among them, the optical transmitter 1000 modulates pilot tone signals of different frequencies onto the optical signals of the corresponding channels. The optical detection device 3000 is used to: obtain a first optical signal from the transmission optical signal on the optical fiber F and filter to obtain the pilot signal carried on the first optical signal. The optical communication performance of each channel during optical communication is obtained through the pilot signal to realize the detection of the optical communication state. In the embodiment of this application, as Figure 1As shown, a low-frequency pilot signal can be modulated on the envelope of a high-frequency optical signal. The optical detection device 3000 can obtain a part of the transmitted optical signal from the optical fiber F based on a small splitting ratio (e.g., 5%) to obtain a first optical signal, and perform various signal processing (such as filtering processing) on the first optical signal to obtain a corresponding pilot optical signal.

[0071] Exemplarily, generally, a pilot signal refers to an optical signal with a certain broadband spectral range after modulation (such as a polarization division multiplexing-16 quadrature amplitude modulation (PDM-16QAM) optical signal with a 50 GHz bandwidth). By a certain method, an additional low-frequency intensity (such as a frequency value in the range of 30 - 60 MHz and a modulation depth in the range of 0.01 - 0.2) modulation is performed on the optical signal envelope to obtain an optical signal of at least one channel. Among them, the modulation depth is defined as: (maximum power of the optical signal - minimum power of the optical signal) / average power of the optical signal. The high-frequency part of the frequency optical signal is the service optical signal carrying service information, and the low-frequency variation part on its envelope is the corresponding pilot signal. Generally, for a dense wavelength division multiplexing optical transmission system, optical signals of multiple wavelengths can be used, such as λ1, λ2, λ3, etc. Generally, in a typical optical transmission system, 80 different wavelengths can be included, that is, from λ1 to λ 80 )). As Figure 2As shown, different wavelengths correspond to different spectral ranges, and pilot signals with different frequencies can be carried on optical signals in different spectral ranges. For example, spectral range 1 corresponds to carrying a pilot signal with a frequency of f1, and spectral range 2 corresponds to carrying a pilot signal with a frequency of f2. The frequency value of the optical signal corresponding to each channel ch can be within the spectral range corresponding to one or more pilot signals (for example, the frequency value of the optical signal corresponding to channel ch1 can be within spectral range 1 and spectral range 2). Each channel ch can be modulated to obtain a high-speed optical signal, such as an optical signal of PDM-16QAM or polarization division multiplexing - quadrature phase shift keying (PDM-QPSK) with a symbol transmission rate of 50GHz - 100GHz baud. In some examples, according to the actual application, the range value of the spectral range corresponding to each pilot signal can be 25GHz, and the spectral range of the frequency optical signal corresponding to each channel ch can be 25GHz and its multiples. During signal transmission, a small part of the optical signal can be received by the optical detection device 3000 for detecting the optical communication performance of signals of each wavelength, such as power detection. A photodetector (PD) can be set in the optical detection device 3000, and the photodetector can convert the received pilot signal into an electrical signal.

[0072] Based on Figure 1 and Figure 2 the pilot signals shown, the connection status of different channels ch can be detected. At the same time, this technology has low cost and rich detection capabilities (it can detect multiple performance parameters). However, in actual applications, the pilot signals between multiple channels ch are affected by the stimulate raman scattering (SRS) effect during optical fiber transmission, and crosstalk will occur between pilot signals of different frequencies, especially in the case of long-distance and multi-channel transmission, this effect is particularly obvious.

[0073] For example, Figure 3Figure (a) shows an example of the optical signal obtained after the initial modulation by the optical transmitter 1000. In the figure, the optical fiber F can transmit optical signals within a certain frequency spectrum. The optical signal is divided into multiple channels ch according to different frequency spectrum ranges. Multiple optical transmitters 1000 transmit optical signals based on different one or more channels ch. One or more optical signals with different wavelengths (corresponding to different frequency spectrum ranges) can be included in each channel ch. The optical signals with different wavelengths include optical signal λ1, optical signal λ2, optical signal λ3, etc. A pilot signal with a frequency of f1 is modulated on the optical signal λ1. A pilot signal with a frequency of f2 is modulated on the optical signal λ2. A pilot signal with a frequency of f3 is modulated on the optical signal λ3 (i.e., each frequency spectrum range can correspond to modulating and carrying a pilot signal with one frequency). Then, as Figure 3 shown in Figure (a), the optical signal is transmitted on the optical fiber F. In an ideal state, only the pilot signal with the corresponding frequency is carried on the optical signals with different wavelengths. By detecting and analyzing the corresponding pilot signal according to the optical signal obtained by the optical detection device 3000 from the optical fiber F, the optical transmission performance of the corresponding channel ch can be obtained. When an optical signal with a certain wavelength (such as optical signal λ1) is dropped at a certain network node on the optical fiber F, no pilot signal with the corresponding frequency can be detected during the subsequent optical fiber transmission. However, in the actual transmission process, due to the influence of the stimulated Raman scattering (SRS) effect of the optical fiber F, crosstalk will occur between pilot signals with different frequencies. As Figure 3 shown in Figure (b), a part of the optical power of the pilot signal with a frequency of f1 on the optical signal λ1 will be transferred to optical signals with other wavelengths (such as optical signal λ2). Taking the optical detection device 3000 receiving the optical signal in the transmission path after the optical signal λ1 is dropped as an example, as Figure 3 shown in Figure (c), if the photodetector of the optical detection device 3000 directly detects the received optical signal, pilot signals with multiple frequency values will be detected on the optical signals with different wavelengths (such as detecting the dropped pilot signal with a frequency of f1); as Figure 3 shown in Figure (d), after filtering the optical signal based on a band pass filter (BPF) and then performing photoelectric conversion based on the photodetector, pilot signals with relevant frequencies of crosstalk can still be detected (such as detecting the dropped pilot signal with a frequency of f1), resulting in misdetection of the relevant optical communication performance of the optical signal λ1. The crosstalk problem caused by SRS makes it impossible for the optical detection device 3000 to accurately detect various performance parameters of different channels ch based on the pilot signal, such as power, etc. And the detection of the power, etc. of the channel ch is the basis for detecting other performance parameters. Therefore, how to solve the influence of SRS is a major problem.

[0074] In order to reduce the pilot signal crosstalk caused by SRS and improve the accuracy of optical communication performance detection, in some possible implementation manners, the optical transmitter 1000 may modulate a pilot signal on an optical signal based on a polyphase balanced transmission technique. The optical detection device 3000 may be an optical detection device that processes pilot signals based on the polyphase balanced transmission technique. In the polyphase balanced transmission technique, two points need to be achieved: First, the optical transmitter 1000 modulates a pilot signal on an optical signal based on the polyphase balanced transmission technique, so that when the optical signal carrying the pilot signal is transmitted on the optical fiber F, the power of the pilot signal in each channel remains zero to achieve the transmission power balance between multiple channels, thereby avoiding the SRS crosstalk problem. Second, on the optical detection device 3000, the pilot signal with zero power in each channel can be accurately detected and acquired. The embodiments of the present application can implement polyphase balanced transmission based on the following solutions:

[0075] In some possible implementation manners, one or more of the multiple optical transmitters 1000 may modulate a carrier optical signal based on the polyphase balanced transmission technique. As Figure 4 shown, the optical transmitter 1000 is configured to: modulate a carrier optical signal to obtain an optical signal including one or more channels ch, and at least one pilot signal f is carried on the optical signal of each channel ch. The optical signal has multiple spectral partitions p, and the multiple spectral partitions p are used to carry pilot signals f with different phases, and the pilot signals f have different phases. The same pilot signal f with different phases is carried on different spectral partitions p of the optical signal; the sum of the powers of at least one pilot signal f in the same channel is less than a certain threshold. Transmit the optical signal to the optical fiber F.

[0076] Exemplarily, the sum of the powers of at least one pilot signal f being less than a certain threshold means that: in an ideal state, there will be power cancellation between different phases of each pilot signal f, so that the sum of the powers of at least one pilot signal f remains zero over time. However, limited by detection technology or actual transmission, the detected power value has a measurable power amount under a certain detection error and / or transmission error. The measurable power amount brought by this detection error and / or transmission error is the aforementioned certain threshold. Or, in actual applications, a threshold may also be preset. As long as it is ensured that the sum of the powers of the same pilot signal with different phases is less than this threshold, the sum of the powers of at least one pilot signal f in the same channel can be made less than a certain threshold. As long as there is a certain degree of power cancellation between the same pilot signals with different phases, the interference caused by the SRS crosstalk problem can be effectively reduced.

[0077] Exemplarily, as Figure 4As shown, the optical transmitter 1000 includes a laser 10 and a signal modulator 20. The laser 10 can provide a carrier optical signal for carrying service information to the signal modulator 20 and so on. The signal modulator 20 modulates the service information onto the carrier optical signal to obtain an optical signal. Moreover, the signal modulator 20 can also modulate a pilot signal onto different spectral partitions p of the optical signal.

[0078] Exemplarily, the signal modulator 20 can modulate the carrier optical signal based on different polarization states to obtain an optical signal.

[0079] In the embodiment of the present application as Figure 4 shown, the carrier optical signal is an optical signal having a certain spectral range and is used to carry different service information. According to the regulations of relevant optical communication technology standards and so on in the optical communication field, the channel ch is divided, and the carrier optical signal corresponding to each channel ch can be within a certain spectral range area. One or more pilot signals f can be modulated onto the carrier optical signal of one channel ch. According to the regulations of relevant optical communication technology standards, the spectral range is divided, and pilot signals f with different frequencies can correspond to corresponding fixed-range spectral regions. For example, generally, the spectral regions of different pilot signals can be divided with a width of 25 GHz. Then according to this division, according to the difference of the pilot signal f carried by each channel ch, when the pilot signal f is modulated onto the carrier optical signal to obtain an optical signal, the spectral range of the optical signal corresponding to each channel ch is different, but can be 25 GHz and its integer multiples. In the above embodiments such as the first optical detection device 3000A, the second optical detection device, and the third optical detection device 3000C, each pilot signal f corresponds to a spectral range of a spectrum, and adjacent pilot signals f will have a crosstalk problem during transmission. And in the embodiment of the present application as Figure 4 shown, each pilot signal f is set to multiple different phases. For each pilot signal f within the channel ch, the spectral range corresponding to the pilot signal f is divided into different spectral partitions p, and each spectral partition p is used to carry the pilot signal f of one phase. Because there is mutual balance between the same pilot signal f of different phases, the power of the same pilot signal f of multiple different phases is zero when transmitted. In this case, the power of the pilot signal f within each channel ch remains zero during transmission, and thus there will be no problem of power crosstalk caused by the influence of the SRS effect. At the same time, as Figure 4 shown, the implementation method can be applied to scenarios of different code patterns.

[0080] In the embodiments of the present application, the channel, the spectral range, and the spectral partition are all a kind of division of the spectral span of the optical signal. The description in the embodiments of the present application that a pilot signal is carried on a certain channel, a pilot signal with a certain frequency value is carried on a certain spectral range, or a pilot signal with a certain phase is carried on a certain spectral partition all means that the pilot signal is carried on the optical signal of the corresponding spectral span by modulation technology.

[0081] Taking the example that a pilot signal is carried on a certain channel: The optical signal is divided into multiple channels according to different spectral spans. Each optical transmitter 1000 performs optical communication based on one or more channels. At this time, the optical transmitter can modulate pilot signals with different frequency values on the optical signal of the corresponding channel, that is, the optical transmitter can modulate the optical signal based on the allocated spectral span and carry pilot signals with different frequency values on the optical signal of the corresponding spectral span to assist in optical communication performance detection, etc. According to the size of the spectral span of the channel, one channel can modulate pilot signals with one or more frequency values.

[0082] Taking the example that a pilot signal with a certain frequency value is carried on a certain spectral range, each channel of the optical transmitter 1000 can be divided into one or more spectral ranges, and each spectral range corresponds to a pilot signal with a spectral value, and the frequency values of the pilot signals in different spectral ranges are different. When the optical transmitter 1000 is performing optical communication, for the optical signal it emits, the pilot signal with the corresponding frequency value is modulated according to the spectral range of the optical signal in the corresponding channel.

[0083] Taking the example that a pilot signal with a certain phase is carried on a certain spectral partition, one spectral partition in a channel corresponds to a pilot signal with a frequency value. When multiple different phases are set for a pilot signal with a frequency value, the spectral range corresponding to the pilot signal with this frequency value can be divided into different spectral partitions. Each spectral partition can correspond to a pilot signal with a phase of this frequency value, or may not correspond to a pilot signal with a phase of this frequency value. When the optical transmitter 1000 is performing optical communication, for the optical signal it emits, the pilot signal with the corresponding frequency value and the corresponding phase is modulated according to the spectral partition of the optical signal in the spectral range of the corresponding channel.

[0084] In some possible implementation manners, multiple optical transmitters 1000 will emit corresponding optical signals to the optical fiber F, and different optical signals form transmitted optical signals transmitted on the optical fiber F. The subsequent optical detection device 3000 on the transmission path can obtain a first optical signal from the transmitted optical signal, and the first optical signal includes optical signals of at least one channel. Based on the above Figure 4 After the optical signals of different channels are transmitted in the shown embodiments, it is also necessary to normally obtain the pilot signals f with different phases based on the optical detection device 3000 to realize the normal detection of the optical communication performance. At this time, such asFigure 5 As shown, the optical detection device 3000 includes a filter 110 and a subsequent signal processing structure X. Among them: The filter 110 is used to: receive a first optical signal. Obtain at least one filtered optical signal based on the first optical signal, and at least one pilot signal is carried on the at least one filtered optical signal. The signal processing structure X is used to: obtain the optical power of the optical signal within the spectral range where at least one pilot signal is located based on the at least one filtered optical signal.

[0085] In the embodiment of the present application as Figure 5 shown, in the optical detection device 3000, it is possible to separate the same pilot signal f with different phases based on the filter 110 to obtain at least one filtered optical signal. Each filtered optical signal carries the obtained at least one pilot signal f, and the same pilot signal f with different phases is carried on different filtered optical signals. By performing certain signal processing on the obtained at least one filtered optical signal through the signal processing structure X after the filter 110, the optical power of the optical signal corresponding to at least one pilot signal can be obtained, thereby completing the performance detection of the optical power.

[0086] In some possible implementation manners, the filter 110 can be a filtering device that can output one, two or more paths. Exemplarily, the filter 110 can be a comb filter. In some examples, according to the different actual output quantities, the filter 110 can be a comb filter with one output, two outputs or more outputs. The spectral range division of the at least one filtered optical signal output by the filter 110 is consistent with the spectral range division of the optical signals of at least one channel. The filter 110 can filter and separate the optical signals in different spectral ranges, and carry one separated part on one filtered optical signal. The filter 110 can filter and output only the optical signals in a part of the spectral ranges among all spectral ranges, or can filter and output the optical signals in multiple partial spectral ranges among all spectral ranges respectively. The optical signals in the filtered output spectral range can be used as one output filtered optical signal, or the optical signals in the multiple filtered output spectral ranges can be used as multiple output filtered optical signals respectively. Exemplarily, the filter 110 can adopt different device structures to form a comb filter. For example, based on a Mach-Zehnder interferometer, a Michelson interferometer, and an interferometer based on an arrayed waveguide grating, etc. And, the center frequency points of the transmittance spectrum of the comb filter can be equally spaced or unequally spaced, and its transmittance spectrum width can also be different.

[0087] In the embodiments of the present application, the filter 110 is a filter that can filter and separate different phases of the same pilot signal f. According to the settings of the phase value and the number of phases of the same pilot signal f during modulation by the optical transmitter 1000, in one case, filters 110 with corresponding separation functions can be set at the optical detection device 3000. For example, when the same pilot signal f has two different phases, a filter 110 with two-way phase separation function can be set. When the same pilot signal f has three different phases, a filter with three-way phase separation function can be set. Similarly, when the same pilot signal f has more different phases, a filter with more-way phase separation function can be set as the filter 110 accordingly. In another case, filters 110 with slightly fewer separation functions can be set at the optical detection device 3000. For example, when the same pilot signal f has N different phases, a filter 110 with a multi-way phase separation function with less than N paths can be set.

[0088] The following is an example of carrying two different phases on the same pilot signal and separating the two phases of the pilot signal f at the optical detection device 3000 throughout the text:

[0089] When the optical detection device 3000 needs to separate signals with multiple phases from the pilot signal, as Figure 6 shown, taking the filter 110 as a comb filter as an example, half of the spectral period length of the comb filter is greater than or equal to the region length of the spectral partition. The signal processing structure X includes a first photodetector 120, a second photodetector 130, and a data processor 200. The comb filter can filter at least one filtered optical signal from the first optical signal. The following will be described by taking the case where at least one filtered optical signal includes two filtered optical signals, namely the first filtered optical signal and the second filtered optical signal, as an example: Among them: The first photodetector 120 is configured to: obtain a first filtered electrical signal according to the first filtered optical signal. The second photodetector 130 is configured to: obtain a second filtered electrical signal according to the second filtered optical signal. The data processor 200 is specifically configured to: obtain the optical power of the optical signal within the spectral range where at least one pilot signal is located according to the first filtered electrical signal and the second filtered electrical signal. In the embodiments of the present application, for the same pilot signal f, the first filtered optical signal and the second filtered optical signal respectively carry different phases of the pilot signal f. The first photodetector 120 and the second photodetector 130 respectively perform photoelectric conversion on the two filtered optical signals to obtain the first filtered electrical signal and the second filtered electrical signal. The data processor 200 can detect the power of the optical signal corresponding to the same pilot signal with multiple phases according to the first filtered electrical signal and the second filtered electrical signal, and detect other optical communication performances based on the optical power.

[0090] In some examples, the duty cycle of the output of the filter is at least one of the following: 12.5%, 25%, 50%, 75%, 87.5%.

[0091] In some examples, as Figure 7 shown, the optical detection device 3000 may include an optical detection single board. The optical detection single board includes an optical processing structure 100 and a data processor 200. Among them, the optical processing structure 100 includes a filter 110, a first photodetector 120, and a second photodetector 130 as shown in Figure 5 and Figure 6 shown. In the embodiments of the present application, single boards are provided in many optical communication related devices, and an independent optical processing structure and a data processor are provided on the single board. Among them, a filter and a photodetector are provided in the optical processing structure to obtain relevant optical signals from the optical fiber F and obtain electrical signals through photoelectric conversion. Then, the optical processing structure transmits the electrical signals to the data processor on the single board for the data processor to perform relevant signal processing work in the digital domain.

[0092] In some examples, as Figure 8 shown, the optical detection device 3000 may include a detection optical processing structure D, and the detection optical processing structure D includes a filter 110, a first photodetector 120, a second photodetector 130, and a data processor 200 as shown in Figure 5 and Figure 6 shown. In the embodiments of the present application, a data processor can be integrated in some optical processing structure products. The optical processing structure can obtain optical signals from the optical fiber F and obtain relevant electrical signals after photoelectric conversion. Then, the data processor inside the optical processing structure can perform relevant signal processing work on the electrical signals in the digital domain and output the processing results.

[0093] Based on the above Figure 4 shown structure of the optical transmitter 1000, the following communication method including operations from step S110 to step S120 as shown in Figure 9 shown can be executed:

[0094] S110. Modulate the carrier optical signal to obtain an optical signal including one or more channels.

[0095] In some possible implementation manners, as Figure 4As shown, a carrier optical signal is modulated to obtain an optical signal including one or more channels ch. At least one pilot signal f is carried on the optical signal corresponding to each channel ch. In an embodiment of the present application, the pilot signal f has different phases, and the same pilot signal f with different phases can be carried on different spectral partitions p of the optical signal, so that during the transmission of the optical signal on the optical fiber F, the sum of the powers of at least one pilot signal of the same channel is less than a certain threshold. In this case, there will be no power leakage problem for the pilot signal f. When the sum of the powers of the pilot signals of multiple channels ch remains zero over time, there will be no SRS crosstalk problem between different channels ch either.

[0096] In some possible implementation manners, the optical transmitter 1000 can carry pilot signals with different phases on fixed spectral partitions p of the optical signal, or can carry pilot signals with different phases on non-fixed spectral partitions p of the optical signal in a time-division manner. It is also possible to carry pilot signals with different phases on the optical signal in a manner combining frequency division and time division.

[0097] In some examples, taking the case where the optical transmitter 1000 carries first pilot signals with two different phases on the optical signal in a frequency-division manner as an example, when the two different phases are a first phase and a second phase with a phase difference of 180° (i.e., being in antiphase), the modulation of the carrier optical signal described above includes: generating the at least one pilot signal, the at least one pilot signal including a first pilot signal, the first pilot signal having a first phase and a second phase, and the first phase and the second phase having a phase difference of 180°. Modulating the first pilot signal onto the carrier optical signal to obtain the optical signal corresponding to the channel. As Figure 10 shown, for the first pilot signal f1 in the at least one pilot signal, the first pilot signal f1 with the first phase and the first pilot signal f1 with the second phase are carried on different spectral partitions p of the optical signal. In an embodiment of the present application, when the optical transmitter 1000 carries pilot signals with two different phases on the optical signal in a frequency-division manner. For the first pilot signal f1, its different phases correspond to fixed spectral partitions p. It only needs to be ensured that during transmission, the first pilot signals f1 with the two phases interact with each other so that the power of the first pilot signal f1 is zero, thereby avoiding the SRS crosstalk problem.

[0098] In some examples, taking the case where the optical transmitter 1000 carries second pilot signals with two different phases in a time-division manner on an unfixed spectral partition p of the optical signal as an example, when the two different phases are the first phase and the second phase with a phase difference of 180° (i.e., in antiphase), the modulation of the carrier optical signal described above includes: generating the at least one pilot signal, the at least one pilot signal including a second pilot signal having a first phase and a second phase, the first phase and the second phase differing by 180°. Modulating the second pilot signals with different phases onto the carrier optical signal to obtain the optical signals of the corresponding channels. As Figure 11 As shown in FIGS. (a), (b), and (c) of Figure 11 , for the second pilot signal f2 in the at least one pilot signal, the phase of the optical signal in the first time slot differs from the phase of the optical signal in the second time slot by 180°. In the embodiment of the present application, the second pilot signal f2 is a pilot signal modulated in a time-division manner. At the optical transmitter 1000, time division is performed with the first time slot and the second time slot. At each time slot, the second pilot signals f2 with different phases correspond to different spectral partitions. At the same time, for the two different time slots, the phases of the same pilot signal in the optical signals of the two time slots also differ by 180°. In this case, based on the time-division scheme, the power of the second pilot signal f2 on the transmission path can be kept zero over time to avoid power leakage or SRS crosstalk problems.

[0099] In some possible implementation manners, when the optical transmitter 1000 modulates the second pilot signal f2 in a time-division manner, a reference pilot signal can also be modulated spectrally. For example, as Figure 11 shown in FIG. (a) of Figure 11 , on the optical signal, there is a second spectral partition between the second pilot signal f2 with the first phase and the second pilot signal f2 with the second phase. A reference pilot signal is also carried on the second spectral partition of the optical signal, and the reference pilot signal has a different frequency from the at least one pilot signal. In the embodiment of the present application, the reference pilot signal can be modulated between the two pilot signals with different phases based on the traditional pilot signal modulation method. During actual transmission, when the reference pilot signal is affected by SRS crosstalk, corresponding changes will occur with the second pilot signal f2. Then, in subsequent optical detection, the intensity of SRS crosstalk can be detected based on the reference pilot signal and the second pilot signal f2.

[0100] In some examples, taking the case where the optical transmitter 1000 carries third pilot signals of two different phases on the optical signal in a time-division manner as an example, when the two different phases are the third phase and the fourth phase with a phase difference of 120°, the modulation of the carrier optical signal described above includes: generating the at least one pilot signal, where the at least one pilot signal includes a third pilot signal, and the third pilot signal has a third phase and a fourth phase, and the third phase and the fourth phase differ by 180°. Modulating the third pilot signals of different phases onto the carrier optical signal to obtain the optical signals of corresponding channels. As Figure 12 shown, for the third pilot signal f3 in the at least one pilot signal: at the first time slot, the third pilot signal f3 of the third phase is carried on the second spectral partition p2 of the optical signal, and the third pilot signal f3 of the fourth phase is carried on the third spectral partition p3 of the optical signal; there is a 120° phase difference between the third phase and the fourth phase. At the second time slot, the third pilot signal f3 of the third phase is carried on the first spectral partition p1 of the optical signal, and the third pilot signal f3 of the fourth phase is carried on the second spectral partition p2 of the optical signal. The first spectral partition p1, the second spectral partition p2, and the third spectral partition p3 are three adjacent spectral partitions p in sequence. In this application, as Figure 10 and Figure 11 in the corresponding embodiments, the two phases are phases that are opposite to each other. And in this application, as Figure 12 in the corresponding embodiments, the angle of 2π is divided into a third phase and a fourth phase with a difference of 120° (for example, 2π / 3 and 4π / 3). In this way, when modulation is performed in a time-division manner, if the spectral partitions p corresponding to the two phases in different time slots are symmetric, it is difficult to achieve the purpose of keeping the sum of the powers of the third pilot signal f3 zero during transmission. And in Figure 12 the corresponding embodiments, by arranging the spectral partitions p corresponding to the two phases in different time slots in a staggered manner (for example: at the first time slot, the third phase is in the second spectral partition p2, and at the second time slot, the third phase is in the first spectral partition p1. At the first time slot, the fourth phase is in the third spectral partition p3, and at the second time slot, the fourth phase is in the second spectral partition p2), the third pilot signals f3 of the third phase and the fourth phase can meet the purpose of keeping the sum of the powers zero during transmission, thereby avoiding the SRS crosstalk problem.

[0101] In some possible embodiments, modulating the carrier optical signal further includes: modulating the carrier optical signal with different polarization states, and different pilot signals are carried on the optical signals with different polarization states. In the embodiments of the present application, the optical transmitter 1000 may perform modulation of optical communication based on different polarization states. For example, modulating based on coherent optical communication with different polarization states can modulate the carrier optical signal to obtain an optical signal including an XI optical signal, an XQ optical signal, a YI optical signal, and a YQ optical signal, where X and Y respectively represent two polarization states of the optical signal, and I and Q respectively represent two orthogonal optical signals under coherent modulation. In this case, corresponding pilot signals can be assigned to the optical signals with different polarization states. In the subsequent optical detection stage, the detection of polarization-dependent loss can be obtained based on the pilot signals with different polarization states.

[0102] In some examples, the optical signal can be modulated based on pilot signals at the level of several MHz. In the embodiments of the present application, since the balanced transmission of the pilot signals is achieved based on multiple phases, the interference of the SRS crosstalk problem is avoided. In this case, the requirement for the frequency of the pilot signal can be reduced. In traditional commercial scenarios, at least several tens of MHz of pilot signals are required to achieve transmission. However, in the embodiments of the present application, the modulation of the pilot signal in the commercial scenario can be achieved at the level of several MHz. After greatly reducing the frequency of the pilot signal, the influence of the dispersion problem of the optical fiber F during long-distance transmission can also be more avoided.

[0103] S120. Transmit an optical signal including one or more channels to the optical fiber F.

[0104] In the embodiments of the present application, each optical transmitter 1000 can modulate to obtain an optical signal related to one or more channels ch. Multiple optical transmitters 1000 can all transmit corresponding optical signals to the optical fiber F. The optical signals corresponding to different optical transmitters 1000 are transmitted on the optical fiber F and can be combined to form a first optical signal.

[0105] In the above Figure 4 , Figure 9 and Figure 10 In the optical communication scenario of the embodiments shown, based on Figure 5 , Figure 6 , Figure 7 and Figure 8 The optical detection device 3000 described in the embodiments shown performs the following detection method including steps S210 - S230 on the first optical signal transmitted on the optical fiber F as shown in Figure 13 shown:

[0106] S210. Receive the first optical signal.

[0107] In the embodiments of the application, the optical communication system 10000 may include one or more asFigure 5 , Figure 6 , Figure 7 and Figure 8 The optical detection device 3000 shown. Based on the optical detection device 3000, a part of the first optical signal can be obtained from the optical fiber F with a small splitting ratio. The first optical signal is based on the above Figure 4 , Figure 9 and Figure 10 The optical signal obtained from the illustrated embodiments, which includes the optical signal of at least one channel ch, and at least one pilot signal f is carried on the optical signal of the channel ch. The pilot signal f has different phases. The same pilot signal f with different phases is carried on different spectral partitions p of the optical signal. The sum of the powers of at least one pilot signal f of the same channel is less than a certain threshold. On the side of the optical detection device 3000, it is necessary to detect the power of the optical signal corresponding to different pilot signals f from the first optical signal, etc.

[0108] Exemplarily, the optical detection device 3000 can filter the transmitted optical signal of the optical fiber F to obtain the first optical signal based on a wavelength selection switch (WSS), etc.

[0109] S220. Obtain at least one filtered optical signal according to the first optical signal.

[0110] In some possible implementation manners, such as Figure 5 , Figure 6 , Figure 7 and Figure 8 shown, different filters can be adaptively set as the filter 110 according to the difference in the number of phases of the same pilot signal on the first optical signal, etc. The filter 110 filters and separates the same pilot signal f with different phases. So that the signal processing structure X after the filter 110 can process the same pilot signal f with different phases to detect the optical power of the optical signal corresponding to the pilot signal f, etc.

[0111] In some possible implementation manners, when the phase of the same pilot signal f is two, a comb filter can be used as the filter 110 to realize the filtering and separation of the same pilot signal f with different phases. Such as Figure 14As shown, it is the filtering and separation principle of a comb filter. The comb filter is essentially an interferometer. The comb filter has a certain period length T. Within the spectral range of its period length T, according to its output duty cycle, the input signal within one period length T is divided into two different optical signals. Taking the duty cycle of both output signals being 50% as an example, two filtered optical signals can be obtained by splitting. The division of the spectral ranges of the two filtered optical signals is consistent with the division of the spectral range of the optical signal input to the filter 110. The filter 110 distributes the input optical signal according to a duty cycle of 50% and 50%, and processes the input optical signal according to the spectral span of the period length T. For the optical signal within the spectral span of each period length T, two filtered optical signals with a spectral span of T / 2 can be obtained by filtering and separation. The spectral range interval where the filtered optical signal within each spectral span of T / 2 is located is consistent with its spectral range interval on the original input optical signal. In the embodiments of the present application, by designing the partition length of the spectral partition p corresponding to the pilot signal f of each phase and selecting a comb filter with a corresponding period length T, the same pilot signal f of two different phases can be filtered and separated onto two different filtered optical signals, so as to achieve precise reception and processing of the pilot signal. Under different pilot signal modulation methods (such as frequency division, time division, and a combination of frequency division and time division, etc.), according to the setting of the region length of the spectral partition p and the period length T of the comb filter, the optical communication performance of optical signals with different code patterns can be detected. In practical applications, comb filters with different period durations T can match channels with multiple code patterns. And this solution can achieve filtering and separation of the pilot signal in channels with different code patterns without strict requirements for the period duration T, and can maintain a high processing accuracy. Since the cost of a comb filter with a larger period length T is also higher, the corresponding period length T and the channel with the corresponding code pattern can be selected according to actual application requirements, cost requirements, code pattern requirements, etc. for pilot modulation, pilot reception processing, etc. The following takes some typical application scenarios as examples:

[0112] In the following, the filtering and separation of the same pilot signal f of two phases by the filter 110 is used as an example for illustration. The relevant content regarding the filtering and separation of the same pilot signal f of more than two phases by the filter 110 can refer to the relevant descriptions of the embodiments of two phases, and will not be elaborated hereinafter.

[0113] In some examples, the optical transmitter 1000 is based on the above Figure 10The illustrated embodiment modulates pilot signals f of a first phase and a second phase with a 180° phase difference onto an optical signal in a frequency-division manner. Taking the example where half of the period length T of the comb filter is equal to the region length of the spectral partition p, when only one first pilot signal f1 is included in a certain channel, taking the spectral range of the channel ch as 25 GHz (i.e., the total spectral range of the first pilot signal f1 is 25 GHz), the period length of the comb filter as 25 GHz, and the output duty cycle as 12.5 GHz, as Figure 15 shown in, after the optical detection device 3000 acquires the corresponding optical signal and performs filtering processing through the comb filter, since the spectral range of the pilot signal is 25 GHz, the first pilot signals f1 of the two phases can respectively occupy the spectral partitions p with a partition length of 12.5 GHz. The output duty cycle of the comb filter is 50%. When the period length of the comb filter is 25 GHz, two filtered optical signals of 12.5 GHz can be output, namely the first filtered optical signal and the second filtered optical signal. Through design, it can be made that the first filtered optical signal (filtered and separated according to a 12.5 GHz spectral range) carries the first pilot signal f1 of the first phase (occupying the spectral partition p with a partition length of 12.5 GHz), and the second filtered optical signal carries the first pilot signal f1 of the second phase.

[0114] Similarly, when Figure 15 shown in the channel ch includes multiple first pilot signals f1, taking the comb filter with a period length of 25 GHz as an example, and the spectral range of the partition length of the spectral partition p is 25 GHz, it can be made that the first filtered optical signal carries the first pilot signal f1 of the first phase, and the second filtered optical signal carries the first pilot signal f1 of the second phase. In the embodiment of the present application, when the partition length (such as 25 GHz) of the spectral partition p corresponding to the first pilot signal f1 of each phase is equal to half (25 GHz) of the period length T of the comb filter, for each first pilot signal f1, it can be divided according to the description in the schematic diagram Figure 14 shown in, the first pilot signal f1 of the first phase is divided onto the first filtered optical signal, and the first pilot signal f1 of the second phase is divided onto the second filtered optical signal. Regarding the description of the case where the region length of the spectral partition p is equal to half of the period length T of the comb filter and more first pilot signals f1 are included in a channel, reference can be made to the relevant description of the embodiment in Figure 15 and will not be elaborated here.

[0115] In some examples, the optical transmitter 1000 is based on the above Figure 10The illustrated embodiment modulates pilot signals f of a first phase and a second phase with a 180° phase difference onto an optical signal in a frequency-division manner. Taking the example where a quarter of the period length T of the comb filter is equal to the region length of the spectral partition p (for example, the spectral range of each pilot signal f is 25 GHz, the spectral partition p corresponding to the pilot signals of the two phases has a partition length of 12.5 GHz each, the period length T of the comb filter is 50 GHz, and the duty cycle of the output of the comb filter is 50%), as Figure 16 shown, when channel ch1 includes two pilot signals f (for example, including a first pilot signal f 1a and a first pilot signal f 1b ), the first filtered optical signal carries the first pilot signal f of the first phase 1a and the first pilot signal f of the second phase 1b ; the second filtered optical signal carries the first pilot signal f of the second phase 1a and the first pilot signal f of the first phase 1b . Since the period length T of the comb filter is 50 GHz and its duty cycle of the output is 50%, the comb filter filters and separates the first filtered optical signal and the second filtered optical signal at a frequency interval of 25 GHz. At this time, for two adjacent pilot signals f, it is necessary to ensure that the two phases of each pilot signal f are carried on different filtered optical signals respectively. Therefore, through design, it can be made that the signals of different phases of two adjacent pilot signals f are on the same output filtered optical signal side of the comb filter. That is, as Figure 16 shown, the first pilot signal f of the first phase in channel ch1 1a is located in the first half cycle of the first output period of the comb filter (for example, filtered and separated onto the first filtered optical signal), the first pilot signal f of the second phase 1a and the first pilot signal f of the first phase 1b are located in the second half cycle of the first output period of the comb filter (for example, filtered and separated onto the second filtered optical signal), and the first pilot signal f of the second phase 1b is located in the first half cycle of the second output period of the comb filter (for example, filtered and separated onto the first filtered optical signal). When a channel ch includes more pilot signals, for example, when it includes three pilot signals f, any two adjacent pilot signals f among the multiple pilot signals f satisfy the relevant description of the first pilot signal in channel ch1. Therefore, reference can be made to Figure 16 for the relevant description of channel ch1, and details will not be repeated.

[0116] In some examples, as Figure 17 shown, the region length of the spectral partition p can also be less than half of the period length T of the comb filter. At this time, it is only necessary to ensure that there is a certain spectral interval between the same pilot signals f.Figure 17 The embodiments shown can be applied to Figure 15 and Figure 16 the code pattern embodiments shown. In the embodiments of the present application, in actual applications, since the output transmittance spectrum of the comb filter is not a regular rectangular spectrum. Therefore, when modulating the pilot signal in the optical transmitter 1000, only the frequency points at some spectral positions can be modulated with the pilot, and in Figure 15 the embodiment shown, the spectral range of 0 - 12.5 GHz can be used as the spectral partition p to modulate the first pilot signal f1 of the first phase. However, in Figure 17 the embodiment shown, the spectral range of 0 - 10 GHz can be used as the spectral partition p to modulate the first pilot signal f1 of the first phase, and the pilot signal is not modulated in the spectral range of 10 - 12.5 GHz. Similarly, in Figure 15 the embodiment shown, the spectral range of 12.5 - 25 GHz is used as the spectral partition p to modulate the first pilot signal f1 of the second phase. However, in Figure 17 the embodiment shown, the spectral range of 15 - 25 GHz can be used as the spectral partition p to adjust the first pilot signal f1 of the second phase, and the pilot signal is not modulated in the spectral range of 12.5 - 15 GHz.

[0117] In some examples, the optical transmitter 1000 modulates the pilot signals f of the first phase and the second phase with a phase difference of 180° onto the optical signal in a time - division manner based on the above Figure 11 shown embodiments. At this time, in the structure as shown in Figure 6 after the optical detection device 3000 acquires the corresponding optical signal and undergoes the filtering process of the comb filter, a time - division filtered optical signal is obtained: in the first time slot, the first filtered optical signal carries the second pilot signal of the first phase, and the second filtered optical signal carries the second pilot signal of the second phase. In the second time slot, the first filtered optical signal carries the second pilot signal of the second phase, and the second filtered optical signal carries the second pilot signal of the first phase. In the embodiments of the present application, on the side of the optical detection device 3000, the separation filtering of the second pilot signal of the first phase and the second pilot signal of the second phase can also be performed in a time - division manner. For example, in the first time slot, the second pilot signal of the first phase is carried on the first filtered optical signal, and the second pilot signal of the second phase is carried on the second filtered optical signal. In the second time slot, the result of the filtered separation is opposite to that in the first time slot. In this way, the optical detection device 3000 can also detect the second pilot signals of different phases in the time - division case, so as to realize the power detection of the optical signal corresponding to the second pilot signal.

[0118] In some examples, the optical transmitter 1000 is based on the above Figure 11The illustrated embodiment modulates second pilot signals f2 with a first phase and a second phase that are 180° out of phase in a time-division manner onto an optical signal. Taking the example where the quarter-period length T of the comb filter is equal to the region length of the spectral partition p (for example, the region length of the spectral partition p is 25 GHz, the period length T of the comb filter is 100 GHz, and the output duty cycle of the comb filter is 50%), the following different time-division methods can be used for modulating the pilot signal:

[0119] Method 1: As shown in Figure 18 When modulating the pilot signal based on the embodiment of FIG. (a) of Figure 11 in the optical transmitter 1000, on the optical signal, there is a second spectral partition p2 between the second pilot signal f2 of the first phase and the second pilot signal f2 of the second phase. On the fourth optical signal detection device 3000, the comb filter performs different filtering and separation of the second pilot signal f2 in different time slots: Since the period length of the comb filter is 100 GHz and its output duty cycle is 50%, the comb filter can perform filtering and separation of the first filtered optical signal and the second filtered optical signal with an output spectral range of 50 GHz. Since the partition length of the spectral partition p occupied by the second pilot signal f2 of one phase is 25 GHz, the partition lengths of two spectral partitions p are equal to half of the period length T of the comb filter. Therefore, for an optical signal with a 75 GHz interval pattern including one second pilot signal f2, in the first time slot, in the first half of the first period duration T of the comb filter, the second pilot signal f2 of the first phase is carried on the first spectral partition p1 of the first filtered optical signal for output. In the second half of the first period duration T of the comb filter, the second pilot signal f2 of the second phase is carried on the third spectral partition p3 of the second filtered optical signal for output. The first spectral partition p1 and the third spectral partition p3 are located in two adjacent output periods of the comb filter. In the second time slot, the second pilot signal f2 of the second phase is carried on the first spectral partition p1 of the first filtered optical signal, and the second pilot signal f2 of the first phase is carried on the third spectral partition p3 of the second filtered optical signal.

[0120] Exemplarily, in the Figure 18 embodiment, if the above optical transmitter 1000 is based on Figure 11 the embodiment of FIG. (a) of Figure 18 and in the embodiment shown in Figure 18In the embodiment, for channel ch1, at the first time slot, the reference pilot signal on the second spectral sub-division p2 and the second pilot signal f2 of the second phase are jointly carried on the second filtered optical signal. At the second time slot, the reference pilot signal on the second spectral sub-division p2 and the second pilot signal f2 of the first phase are jointly carried on the second filtered optical signal. Subsequently, the power difference between the second pilot signal f2 and the reference pilot signal can be calculated based on the first filtered optical signal and the second filtered optical signal to detect the SRS crosstalk.

[0121] Method 2: When the pilot signal modulation is performed in the optical transmitter 1000 based on Figure 11 the embodiment shown in FIG. (b) of, at the first time slot, the second pilot signal f2 of the first phase is carried on the first spectral sub-division p1 of the first filtered optical signal, and the second pilot signal f2 of the second phase is carried on the second spectral sub-division p2 of the second filtered optical signal; the first spectral sub-division p1 and the second spectral sub-division p2 are two adjacent spectral sub-divisions p. At the second time slot, the second pilot signal f2 of the second phase is carried on the first spectral sub-division p1 of the first filtered optical signal, and the second pilot signal f2 of the first phase is carried on the second spectral sub-division p2 of the second filtered optical signal. In the embodiment of the present application, the third spectral sub-division p3 after the second spectral sub-division p2 can be set as the spectral sub-division p that does not carry the pilot signal, and it can be achieved by design that the second pilot signal f2 of the first phase and the second pilot signal f2 of the second phase are carried on different filtered optical signals respectively. The specific implementation principle of Method 2 can refer to the specific implementation principle of Method 1 above and will not be elaborated here.

[0122] Method 3: When the optical transmitter 1000 is based on Figure 11When performing pilot signal modulation on the embodiment shown in FIG. (c), in the first time slot, the second pilot signal f2 with the first phase is carried on the first spectral partition p1 of the first filtered optical signal, and the second pilot signal f2 with the second phase is carried on the second spectral partition p2 and the third spectral partition p3 of the second filtered optical signal. The first spectral partition p1, the second spectral partition p2, and the third spectral partition p3 are three adjacent spectral partitions p in sequence. In the second time slot, the second pilot signal f2 with the second phase is carried on the first spectral partition p1 of the first filtered optical signal, and the second pilot signal f2 with the first phase is carried on the second spectral partition p2 and the third spectral partition p3 of the second filtered optical signal. The modulation signal amplitudes of the second pilot signal f2 corresponding to the second spectral partition p2 and the third spectral partition p3 are respectively half of the modulation signal amplitude of the second pilot signal f2 corresponding to the first spectral partition p1. In the embodiment of the present application, for the spectral range interval of the 75 GHz code pattern, it can be divided into three 25 GHz spectral partitions: the first spectral partition p1, the second spectral partition p2, and the third spectral partition p3. A second pilot signal f2 with a certain phase can be carried on the first spectral partition p1, and a second pilot signal f2 with another phase can be carried on the second spectral partition p2 and the third spectral partition p3. Since the spectral range of the second pilot signal f2 in the second spectral partition p2 and the third spectral partition p3 is twice that of the second pilot signal f2 in the first spectral partition p1, the modulation signal amplitudes of the second pilot signal f2 corresponding to the second spectral partition p2 and the third spectral partition p3 can be respectively set to half of the modulation signal amplitude of the second pilot signal f2 corresponding to the first spectral partition p1, so as to achieve power balance of the second pilot signal f2 with multiple phases in different time slots. On the side of the optical detection device 3000, in order to accurately receive the second pilot signal f2 with two different phases, the second spectral partition p2 and the third spectral partition p3 can be used as an output spectrum of the comb filter, so that the second pilot signal f2 with the same phase in the two spectral partitions p can be carried on the same filtered optical signal at the same time, while the second pilot signal f2 with another phase in the first spectral partition p1 can be carried on another filtered optical signal. The specific implementation method of Method 3 can refer to the relevant description of Method 1 above and will not be elaborated here.

[0123] In the above Method 3, the duty cycles of the two outputs based on the comb filter are respectively described as 50%. However, when the duty cycles of the two outputs of the comb filter are other ratios, the second pilot signal f2 on the second filtered optical signal may be carried on more spectral partitions p (for example, on N spectral partitions p), and the modulation signal amplitude of each second pilot signal f2 on the second filtered optical signal is 1 / n of the modulation signal amplitude of the second pilot signal f2 on the first filtered optical signal. For example, when the duty cycles of the two outputs of the comb filter are 25% (corresponding to the output duty cycle of the first filtered optical signal) and 75% (corresponding to the output duty cycle of the second filtered optical signal) respectively, there can be a second pilot signal f2 in one spectral partition p on the first filtered optical signal, and there can be three second pilot signals f2 in three spectral partitions p on the second filtered optical signal. At this time, the second pilot signal f2 on the second filtered optical signal is carried on 3 spectral partitions p, then the modulation signal amplitude of each second pilot signal f2 in each spectral partition p on the second filtered optical signal needs to be equal to 1 / 3 of the modulation signal amplitude of the second pilot signal f2 in one spectral partition p on the first filtered optical signal to ensure that the optical powers of the second pilot signals f2 with two different phases can be cancelled as much as possible. Similarly, for the case where the comb filter has more outputs, the description of the two outputs above can be referred to and will not be elaborated here.

[0124] The above gives implementation examples of the time division scheme for the pilot signals of the first phase and the second phase in the case where the phase difference is 180° based on Method 1, Method 2 and Method 3. In some possible cases, the optical transmitter 1000 is based on the above Figure 12In the illustrated embodiment, the third pilot signal f3 with a third phase and a fourth phase having a phase difference of 120° is modulated onto the optical signal in a time-division manner. Taking the example where the quarter-period length T of the comb filter is equal to the region length of the spectral partition p (for example, the region length of the spectral partition p is 25 GHz, the period length T of the comb filter is 100 GHz, and the output duty cycle of the comb filter is 50%), the following different time-division methods can be used for modulating the pilot signal: In the first time slot, the third pilot signal f3 with the third phase is carried on the second spectral partition p2 of the first filtered optical signal, and the third pilot signal f3 with the fourth phase is carried on the third spectral partition p3 of the second filtered optical signal. In the second time slot, the third pilot signal f3 with the third phase is carried on the first spectral partition p1 of the first filtered optical signal, and the third pilot signal f3 with the fourth phase is carried on the second spectral partition p2 of the second filtered optical signal. The first spectral partition p1, the second spectral partition p2, and the third spectral partition p3 are three adjacent spectral partitions p in sequence. In the embodiment of the present application, since the third phase and the fourth phase are not a pair of phases that are opposite to each other like the first phase and the second phase. Therefore, in the embodiment of the present application, when the optical transmitter 1000 is in different time slots, the third phase and the fourth phase are misaligned and modulated on the three spectral partitions p to achieve balanced transmission of the third pilot signal f3. At the same time, on the side of the optical detection device 3000, in the first time slot and the second time slot, the third pilot signal f3 on the first spectral partition p1 is always carried on the first filtered optical signal, and the third pilot signal f3 on the second spectral partition p2 and the third spectral partition p3 is carried on the second filtered optical signal, so as to achieve the reception of the third pilot signal f3 with different phases. However, in this way, compared with the above scheme of the first phase and the second phase, the scheme of the third phase and the fourth phase cannot achieve perfect reception and detection processing of the third pilot signal f3.

[0125] The above embodiments in step S220 are only examples of the application of several common scenarios of the comb filter when the duty cycle is 50%. In actual applications, according to different values of the duty cycle of the comb filter and the value of the period length T, as well as different channel code patterns, the partition length of each spectral partition p, etc., design adjustments can be made adaptively. The specific design adjustment ideas can refer to the design ideas of the above embodiments and will not be elaborated here. In actual applications, as long as it satisfies carrying the same pilot signal with different phases on different spectral partitions p to achieve multi-phase transmission under power balance and filtering and separating the same pilot signal with different phases at the optical detection device, the multi-phase balanced pilot technology proposed in the embodiment of the present application is adopted.

[0126] In the above embodiments, an example is given where the same pilot signal has two phases, and a filter is set to separately output two filtered optical signals. For the case where N phases are set in the same pilot signal and N filtered optical signals are separately output based on the filter, reference can be made to the description of the above embodiments, which will not be elaborated here. In addition, when N phases are set in the same pilot signal, it is also possible to separately output less than N filtered optical signals based on the filter. For example, multiple phases (such as two or three, etc.) can be set in the same pilot signal, and one filtered optical signal can be separately output based on the filter. The separately output one filtered optical signal can be any one of the filtered optical signals in the embodiment where N filtered optical signals are separately output for the above N phases. Taking the above Figure 11 embodiment as an example, in the Figure 11 embodiment, the same pilot signal can have a first phase and a second phase. Filtering and separating the two phases of the optical signal in Figure 11 (a) diagram can obtain the Figure 18 shown first filtered optical signal and second filtered optical signal. In actual applications, when the filter filters and separates the optical signal with two phases, it can also only output the first filtered optical signal or the second filtered optical signal. Based on the pilot signal with a single phase on the first filtered optical signal or the second filtered optical signal, the detection of optical communication performance can be achieved. Compared with the scenario based on multiple filtered optical signals, it can also receive and process all the pilot signals, but it is only unable to receive each pilot signal of all phases, and there is a certain reception loss in signal processing. Similarly, three different phases with a 120° phase difference can also be set on the same pilot signal, and only two filtered optical signals are filtered and output at the optical detection device 3000. Each of the two filtered optical signals has the pilot signal with one of the three different phases.

[0127] S230. Perform optical communication performance detection according to at least one filtered optical signal.

[0128] In the embodiments of the present application, as Figure 5 shown, the signal processing structure X after the filter 110 can detect the optical communication performance based on at least one filtered optical signal. For example, obtain the optical power of the optical signal where at least one pilot signal is located according to the first filtered optical signal and the second filtered optical signal.

[0129] In some possible implementation manners, when the optical transmitter 1000 is based on a time-division scheme and a reference pilot signal is modulated in the second frequency spectrum partition p between the second pilot signals f2 of the first phase and the second phase. As Figure 6 、 Figure 7 and Figure 8As shown, the data processor 200 is further configured to: obtain the stimulated Raman scattering crosstalk degree of the second pilot signal f2 based on the first filtered electrical signal and the second filtered electrical signal.

[0130] In some possible implementation manners, when the optical transmitter 1000 implements signal modulation of the optical signal based on optical signals with different polarization states, the optical signals of at least one channel have different polarization states, and different pilot signals are carried on the optical signals with different polarization states. At this time, as Figure 5 shown, the signal processing structure X is further configured to: obtain the polarization-dependent loss of the optical signal based on at least one filtered optical signal. Exemplarily, it can be Figure 6 、 Figure 7 and Figure 8 shown that the data processor 200 calculates the polarization-dependent loss of the optical signal based on at least one filtered optical signal. In the embodiments of the present application, when the optical signals with different polarization states correspond to different pilot signals, the polarization-dependent loss can be calculated according to the powers of the pilot signals corresponding to different polarization states, so as to detect more optical communication performance parameters.

[0131] In some possible implementation manners, when multiple pilot signals are carried on the optical signal of one channel, as Figure 5 shown, the signal processing structure X is still configured to: obtain the filtering processing capability of the channel based on at least one filtered optical signal. Exemplarily, the filtering processing capability of the channel can be obtained according to the signal insertion loss ratio of at least one filtered electrical signal, and the signal insertion loss ratio is the ratio of the first insertion loss value to the second insertion loss value, where the first insertion loss value is the insertion loss values of the pilot signals of the two phases corresponding to the maximum frequency partition and the minimum frequency partition in the spectrum range corresponding to the channel, and the second insertion loss value is the insertion loss values of the pilot signals of all other phases except the two phases corresponding to the maximum frequency partition and the minimum frequency partition in the spectrum partition corresponding to the channel. In the embodiments of the present application, the filtering performance of the WSS for different channels can also be detected based on at least one filtered optical signal.

[0132] Embodiments of the present application provide an optical detection device, an optical transmitter, a detection method, and a communication method. When modulating an optical signal carrying service information, the optical transmitter modulates the same pilot signal in one channel to different spectral partitions of the optical signal with different phases, so that when the optical signal is transmitted on an optical fiber, the sum of the powers of at least one pilot signal in the same channel is less than a certain threshold. Through the above pilot signal modulation method, when the optical signal is transmitted on the optical fiber, the pilot signals in different channels thereof will not be affected by the SRS effect and cause power crosstalk problems. At the same time, during the transmission of the optical signal, the optical detection device can filter and separate different phases of the same pilot signal in the channel based on a filter, so as to enable the normal reception of pilot signals with multiple phases, thereby realizing the normal optical communication performance detection based on the pilot signals modulated by the above optical transmitter. Based on the above optical detection device, optical communication performance detection can be realized at low cost and high precision, and it can be applied to different code patterns. At the same time, the optical detection device does not have strict requirements on the accuracy of the filter. Taking a comb filter as an example, the comb filter with a larger period length has a lower price cost. And the embodiments of the present application can adopt comb filters with different costs and different specifications to adapt to the reception and processing of pilot signals in channels with different code patterns.

[0133] Embodiments of the present application also propose a computer-readable storage medium, which includes instructions that, when running on a data processor, cause the data processor to execute the detection method (such as the detection methods described in the above Figure 13 , Figure 15 , Figure 16 , Figure 18 and

[0134] related embodiments).

[0135] The memory involved in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchlink dynamic random access memory (SLDRAM), and direct rambus random access memory (DR RAM). It should be noted that the memories of the systems and methods described herein are intended to include, but are not limited to, these and any other suitable types of memories.

[0136] It should be understood that in various embodiments of the present application, the order numbers of the above processes do not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0137] Those of ordinary skill in the art can realize that the modules and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or by a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0138] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the systems, devices, and modules described above can refer to the corresponding processes in the foregoing method embodiments, and will not be described herein again.

[0139] In several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules is only a logical function division. In actual implementation, there may be other division methods. For example, multiple modules or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling, direct coupling, or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of devices or modules can be in electrical, mechanical, or other forms.

[0140] The modules described as separate components may or may not be physically separated. The components shown as modules may or may not be physical modules, that is, they can be located in one device or distributed to multiple devices. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0141] In addition, the functional modules in each embodiment of this application can be integrated in one device, or each module can exist physically alone, or two or more modules can be integrated in one device.

[0142] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using a software program, it can be implemented in whole or in part 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 and executed on a computer, the processes or functions described in the embodiments of this application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from a website, computer, server, or data center to another website, computer, server, or data center in a wired manner (such as coaxial cable, optical fiber, Digital Subscriber Line (DSL)) or wirelessly (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that the computer can access or a data storage device such as a server or data center that contains one or more integrated media. The available medium can be a magnetic medium (such as a floppy disk, hard disk, magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a Solid State Disk (SSD)), etc.

[0143] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims described above.

Claims

1. A light detection device, characterized in that, It includes a filter and a signal processing structure; wherein: The filter is used for: Receiving a first optical signal, the first optical signal including optical signals of at least one channel, each optical signal of the channel carrying at least one pilot signal, different pilot signals corresponding to different spectral ranges within the channel, the pilot signals having different phases, and the same pilot signal with different phases corresponding to different spectral sub-regions within the spectral range; the sum of the powers of the at least one pilot signal in the same channel being less than a certain threshold; Filtering the first optical signal to obtain at least one filtered optical signal, the at least one filtered optical signal carrying the at least one pilot signal; The signal processing structure is used for: obtaining the optical power of the optical signal within the spectral range where the at least one pilot signal is located according to the at least one filtered optical signal.

2. The optical detection device according to claim 1, wherein Half of the spectral period length of the filter is greater than or equal to the regional length of the spectral sub-region; the signal processing structure includes a first photodetector, a second photodetector, and a data processor; wherein: The filter is used for: filtering the first optical signal to obtain at least one filtered optical signal, the at least one filtered optical signal including a first filtered optical signal and a second filtered optical signal; The first photodetector is used for: performing photoelectric conversion on the first filtered optical signal to obtain a first filtered electrical signal; The second photodetector is used for: performing photoelectric conversion on the second filtered optical signal to obtain a second filtered electrical signal; The data processor is specifically used for: obtaining the optical power of the optical signal within the spectral range where the at least one pilot signal is located according to the first filtered electrical signal and the second filtered electrical signal.

3. The optical detection device according to claim 1 or 2, characterized in that, The at least one filtered optical signal includes a first filtered optical signal and a second filtered optical signal; the at least one pilot signal includes a first pilot signal, the first filtered optical signal carrying the first pilot signal with a first phase, and the second filtered optical signal carrying the first pilot signal with a second phase; the first phase and the second phase differ by 180°.

4. The optical detection device according to any one of claims 1-3, characterized in that, The at least one filtered optical signal includes a first filtered optical signal and a second filtered optical signal; the at least one pilot signal further includes a second pilot signal; In a first time slot, the first filtered optical signal carries the second pilot signal with a first phase, and the second filtered optical signal carries the second pilot signal with a second phase; the first phase and the second phase differ by 180°; In a second time slot, the first filtered optical signal carries the second pilot signal with a second phase, and the second filtered optical signal carries the second pilot signal with a first phase, the first time slot and the second time slot alternating with each other.

5. The optical detection device according to claim 4, characterized in that, The spectral range division of the first filtered optical signal and the second filtered optical signal is consistent with the spectral range division of the optical signal of the at least one channel; a quarter of the period length of the filter is equal to the regional length of the spectral sub-region; on the optical signal of the corresponding channel, there is a second spectral sub-region between the second pilot signal with a first phase and the second pilot signal with a second phase; At the first time slot, the second pilot signal with the first phase corresponds to the first spectral partition of the first filtered optical signal, and the second pilot signal with the second phase corresponds to the third spectral partition of the second filtered optical signal; the first spectral partition, the second spectral partition, and the third spectral partition are three sequentially adjacent spectral partitions; At the second time slot, the second pilot signal with the second phase corresponds to the first spectral partition of the first filtered optical signal, and the second pilot signal with the first phase corresponds to the third spectral partition of the second filtered optical signal.

6. The optical detection device according to claim 4, wherein The spectral range division of the first filtered optical signal and the second filtered optical signal is consistent with the spectral range division of the optical signals of the at least one channel; a reference pilot signal is further carried on the optical signal of the corresponding channel, the reference pilot signal corresponds to the second spectral partition of the second filtered optical signal, and the frequency of the reference pilot signal is different from that of the at least one pilot signal; the data processor is further configured to: Obtain the stimulated Raman scattering crosstalk degree of the second pilot signal according to the first filtered electrical signal and the second filtered electrical signal.

7. The optical detection device according to claim 4, wherein The spectral range division of the first filtered optical signal and the second filtered optical signal is consistent with the spectral range division of the optical signals of the at least one channel; the quarter-period length of the filter is equal to the partition length of the spectral partition; At the first time slot, the second pilot signal with the first phase corresponds to the first spectral partition of the first filtered optical signal, and the second pilot signal with the second phase corresponds to the second spectral partition of the second filtered optical signal; At the second time slot, the second pilot signal with the second phase corresponds to the first spectral partition of the first filtered optical signal, and the second pilot signal with the first phase corresponds to the second spectral partition of the second filtered optical signal; There is no corresponding pilot signal in the third spectral partition of the second filtered optical signal, and the first spectral partition, the second spectral partition, and the third spectral partition are three sequentially adjacent spectral partitions.

8. The optical detection device according to claim 4, wherein, The spectral range division of the first filtered optical signal and the second filtered optical signal is consistent with the spectral range division of the optical signals of the at least one channel; the quarter-period length of the filter is equal to the partition length of the spectral partition; At the first time slot, the second pilot signal with the first phase corresponds to the first spectral partition of the first filtered optical signal, and the second pilot signal with the second phase corresponds to the second spectral partition and the third spectral partition of the second filtered optical signal; the first spectral partition, the second spectral partition, and the third spectral partition are three sequentially adjacent spectral partitions; At the second time slot, the second pilot signal with the second phase corresponds to the first spectral partition of the first filtered optical signal, and the second pilot signal with the first phase corresponds to the second spectral partition and the third spectral partition of the second filtered optical signal; The modulation signal amplitudes of the second pilot signals corresponding to the second spectral partition and the third spectral partition are respectively half of the modulation signal amplitude of the second pilot signal corresponding to the first spectral partition.

9. The optical detection device according to claim 2, wherein, The at least one filtered optical signal includes a first filtered optical signal and a second filtered optical signal; the spectral range division of the first filtered optical signal and the second filtered optical signal is consistent with the spectral range division of the optical signals of the at least one channel; the quarter-period length of the filter is equal to the partition length of the spectral partition; the at least one pilot signal includes a third pilot signal; At a first time slot, the third pilot signal with a third phase corresponds to a second spectral partition of the first filtered optical signal, and the third pilot signal with a fourth phase corresponds to a third spectral partition of the second filtered optical signal; there is a 120° phase difference between the third phase and the fourth phase; At a second time slot, the third pilot signal with the third phase corresponds to a first spectral partition of the first filtered optical signal, and the third pilot signal with the fourth phase corresponds to the second spectral partition of the second filtered optical signal; The first spectral partition, the second spectral partition, and the third spectral partition are three adjacent spectral partitions in sequence.

10. The optical detection device according to any one of claims 1-9, characterized in that, The optical signals of the at least one channel have different polarization states, and different pilot signals are carried on the optical signals with different polarization states; the signal processing structure is further configured to: Obtain the polarization-dependent loss of the optical signals of the at least one channel according to the at least one filtered optical signal.

11. The optical detection device according to any one of claims 1-10, characterized in that, The filter is a comb filter.

12. An optical transmitter, characterized in that, The optical transmitter is configured to: Modulate a carrier optical signal to obtain an optical signal including one or more channels, at least one pilot signal is carried on the optical signal of each channel, different pilot signals correspond to different spectral ranges within the channel, the pilot signals have different phases, and the same pilot signal with different phases corresponds to different spectral partitions within the spectral range; the sum of the powers of the at least one pilot signal of the same channel is less than a certain threshold; Transmit the optical signal including one or more channels to an optical fiber.

13. The optical transmitter according to claim 12, wherein The modulating the carrier optical signal to obtain an optical signal including one or more channels includes: Generating the at least one pilot signal, the at least one pilot signal includes a first pilot signal, the first pilot signal has a first phase and a second phase, and the first phase and the second phase differ by 180°; Modulating the first pilot signal onto the carrier optical signal to obtain an optical signal corresponding to a channel, and the first pilot signal with the first phase and the first pilot signal with the second phase correspond to different spectral partitions within the spectral range.

14. The optical transmitter according to claim 12 or 13, characterized in that, The modulating the carrier optical signal to obtain an optical signal including one or more channels includes: Generating the at least one pilot signal, the at least one pilot signal includes a second pilot signal, the second pilot signal has a first phase and a second phase, and the first phase and the second phase differ by 180°; Modulating the second pilot signal with different phases onto the carrier optical signal to obtain an optical signal corresponding to a channel; at the first time slot and the second time slot, the second pilot signal with the same phase corresponds to different spectral partitions within the spectral range, and the first time slot and the second time slot alternate with each other.

15. The optical transmitter according to claim 14, characterized in that, On the optical signal of the corresponding channel, there is a second spectral partition between the second pilot signal of the first phase and the second pilot signal of the second phase; modulating the carrier optical signal to obtain an optical signal including one or more channels further includes: Modulating a reference pilot signal to correspond to the second spectral partition within the channel, the reference pilot signal having a different frequency from the at least one pilot signal.

16. The optical transmitter according to any one of claims 12-15, characterized in that, Modulating the carrier optical signal to obtain an optical signal including one or more channels includes: Generating the at least one pilot signal, the at least one pilot signal including a third pilot signal having a third phase and a fourth phase, the third phase and the fourth phase differing by 180°; Modulating the third pilot signals of different phases onto the carrier optical signal to obtain an optical signal corresponding to the channel; at a first time slot, the third pilot signal of the third phase corresponds to the second spectral partition within the channel, and the third pilot signal of the fourth phase corresponds to the third spectral partition within the channel; at a second time slot, the third pilot signal of the third phase corresponds to the first spectral partition within the channel, and the third pilot signal of the fourth phase corresponds to the second spectral partition within the channel; the first time slot and the second time slot alternate with each other; the first spectral partition, the second spectral partition, and the third spectral partition are three sequentially adjacent spectral partitions.

17. The optical transmitter according to any one of claims 12-16, characterized in that, Modulating the carrier optical signal to obtain an optical signal including one or more channels further includes: Modulating the carrier optical signal with different polarization states, different pilot signals being carried on the optical signals of different polarization states.

18. A detection method, characterized in that, Based on an optical detection device, the optical detection device including a filter; the method includes: Receiving a first optical signal, the first optical signal including an optical signal of at least one channel, each optical signal of the channel carrying at least one pilot signal, different pilot signals corresponding to different spectral ranges within the channel, the pilot signals having different phases, the same pilot signal of different phases corresponding to different spectral partitions within the spectral range; the sum of the powers of the at least one pilot signal of the same channel being less than a certain threshold; Filtering the first optical signal to obtain at least one filtered optical signal, the at least one filtered optical signal carrying the at least one pilot signal; The signal processing structure is configured to: obtain the optical power of the optical signal within the spectral range where the at least one pilot signal is located according to the at least one filtered optical signal.

19. The detection method according to claim 18, characterized in that, The at least one filtered optical signal includes a first filtered optical signal and a second filtered optical signal; Filtering the first optical signal to obtain at least one filtered optical signal includes: filtering the first optical signal to obtain at least one filtered optical signal, the at least one filtered optical signal including a first filtered optical signal and a second filtered optical signal; Obtaining the optical power of the optical signal within the spectral range where the at least one pilot signal is located according to the at least one filtered optical signal includes: performing photoelectric conversion on the first filtered optical signal to obtain a first filtered electrical signal; performing photoelectric conversion on the second filtered optical signal to obtain a second filtered electrical signal; and obtaining the optical power of the optical signal within the spectral range where the at least one pilot signal is located according to the first filtered electrical signal and the second filtered electrical signal.

20. The detection method according to claim 18 or 19, characterized in that, The at least one filtered optical signal includes a first filtered optical signal and a second filtered optical signal; the spectral range division of the first filtered optical signal and the second filtered optical signal is consistent with the spectral range division of the optical signals of the at least one channel; the at least one pilot signal further includes a second pilot signal; on the optical signal of the corresponding channel, there is a second spectral sub-region between the second pilot signal of the first phase and the second pilot signal of the second phase; the optical signal of the corresponding channel further carries a reference pilot signal, the reference pilot signal corresponds to the second spectral sub-region, and the frequency of the reference pilot signal is different from that of the at least one pilot signal; the method further includes: Obtaining the stimulated Raman scattering crosstalk degree of the second pilot signal according to the first filtered electrical signal and the second filtered electrical signal.

21. The detection method according to any one of claims 18-20, characterized in that, The optical signals of the at least one channel have different polarization states, and different pilot signals are carried on the optical signals of different polarization states; the method further includes: Obtaining the polarization-dependent loss of the optical signals of the at least one channel according to the at least one filtered optical signal.

22. A communication method, characterized in that, Based on an optical transmitter; the method includes: Modulating a carrier optical signal to obtain an optical signal including one or more channels, at least one pilot signal is carried on the optical signal of each channel, different pilot signals correspond to different spectral ranges within the channel, the pilot signals have different phases, and different spectral sub-regions within the spectral range corresponding to the same pilot signal of different phases; the sum of the powers of the at least one pilot signal of the same channel is less than a certain threshold; Transmitting the optical signal of the one or more channels to an optical fiber.

23. The communication method according to claim 22, wherein The modulating the carrier optical signal to obtain an optical signal including one or more channels includes: Generating the at least one pilot signal, the at least one pilot signal includes a first pilot signal, the first pilot signal has a first phase and a second phase, and the first phase and the second phase differ by 180°; Modulating the first pilot signal onto the carrier optical signal to obtain the optical signal of the corresponding channel, and different spectral sub-regions within the spectral range correspond to the first pilot signal of the first phase and the first pilot signal of the second phase.

24. The communication method according to claim 22 or 23, characterized in that, The modulating the carrier optical signal to obtain an optical signal including one or more channels includes: Generating the at least one pilot signal, the at least one pilot signal includes a second pilot signal, the second pilot signal has a first phase and a second phase, and the first phase and the second phase differ by 180°; In the first time slot and the second time slot, the second pilot signal with the same phase is modulated into optical signals corresponding to different spectral partitions of the carrier optical signal to obtain optical signals corresponding to channels, and the first time slot and the second time slot alternate with each other.

25. The communication method according to claim 24, wherein On the optical signal corresponding to the channel, there is a second spectral partition between the second pilot signal with the first phase and the second pilot signal with the second phase; modulating the carrier optical signal to obtain an optical signal including one or more channels further includes: Modulating a reference pilot signal into the second spectral partition within the corresponding channel, where the frequency of the reference pilot signal is different from that of the at least one pilot signal.

26. The communication method according to any one of claims 22-25, characterized in that, Modulating the carrier optical signal to obtain an optical signal including one or more channels includes: Generating the at least one pilot signal, where the at least one pilot signal includes a third pilot signal, and the third pilot signal has a third phase and a fourth phase, and the third phase and the fourth phase differ by 180°. Modulating the third pilot signal with different phases onto the carrier optical signal to obtain an optical signal corresponding to the channel; in the first time slot, the third pilot signal with the third phase corresponds to the second spectral partition, and the third pilot signal with the fourth phase corresponds to the third spectral partition; in the second time slot, the third pilot signal with the third phase corresponds to the first spectral partition, and the third pilot signal with the fourth phase corresponds to the second spectral partition; the first time slot and the second time slot alternate with each other; the first spectral partition, the second spectral partition, and the third spectral partition are three adjacent spectral partitions in sequence.

27. The communication method according to any one of claims 22-26, characterized in that, Modulating the carrier optical signal to obtain an optical signal including one or more channels further includes: Modulating the carrier optical signal with different polarization states, and different pilot signals are carried on the optical signals with different polarization states.

28. An optical communication system, characterized in that, Including at least one optical detection device according to any one of claims 1-11 and a plurality of optical transmitters according to any one of claims 12-17; the optical transmitter and the optical detection device are respectively coupled to an optical fiber.

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