An optical receiving module, data transmission method and related device

Abstract

Embodiments of the present application provide an optical receiving module, a data transmission method and related equipment, for improving the bandwidth of the optical receiving module. The optical receiving module provided by the embodiments of the present application comprises a 1xN optical splitter, N optical-electric conversion modules, N analog-digital converters ADCs and a processor. The 1xN optical splitter is connected with the N optical-electric conversion modules, the N optical-electric conversion modules are connected with the N ADCs one by one, and the N ADCs are connected with the processor. The optical splitter is configured to split a broadband optical signal into N paths of optical signals and input the N paths of optical signals into the N optical-electric conversion modules respectively. The optical-electric conversion module is configured to perform optical-electric conversion on the optical signal to obtain a sub-band electric signal of the broadband optical signal. The N sub-band electric signals are sequentially connected in frequency, and the frequency interval of the marker signals of the N sub-band electric signals is fixed as a first frequency interval. The ADC is configured to perform analog-digital conversion on the sub-band electric signal to obtain a digital signal. The processor is configured to splice the digital signals from the N ADCs based on the first frequency interval to obtain a broadband digital signal.

Description

Technical Field

[0001] This application relates to the field of optical communication, and in particular to an optical receiving module, a data transmission method, and related equipment. Background Technology

[0002] In the field of optical communication, optical signals are received using optical receiver modules. These modules include photoelectric converters and analog-to-digital converters. The photoelectric converter converts optical signals into electrical signals, while the analog-to-digital converter converts electrical signals from analog to digital.

[0003] With the development of optical communication technology, the bandwidth of optical signals is increasing, thus placing greater demands on the bandwidth of optical receiving modules. However, current optical receiving modules have limited bandwidth due to the limited bandwidth of their photoelectric conversion modules and analog-to-digital converters, resulting in a restricted receiveable signal bandwidth and limiting the potential for further increases in optical signal bandwidth. Therefore, there is an urgent need for a high-bandwidth optical receiving module. Summary of the Invention

[0004] This application provides an optical receiving module, a data transmission method, and related equipment to improve the bandwidth of the optical receiving module.

[0005] In a first aspect, embodiments of this application provide an optical receiving module. The optical receiving module includes: a 1xN beam splitter, N photoelectric conversion modules, N analog-to-digital converters (ADCs), and a processor, where N is a positive integer and N≥2; the 1xN beam splitter is connected to the N photoelectric conversion modules, the N photoelectric conversion modules are connected to the N ADCs one by one, and the N ADCs are connected to the processor; the beam splitter is used to divide the receiving broadband optical signal (i.e., the broadband optical signal received by the optical receiving module) into N optical signals, which are then input to the N photoelectric conversion modules respectively; the photoelectric conversion modules are used to perform photoelectric conversion on the optical signals to obtain receiving terminal charged signals of the receiving broadband optical signal, the N receiving terminal charged signals are sequentially connected in frequency, and the frequency interval of the marker signals of the N receiving terminal charged signals is fixed at a first frequency interval; the ADCs are used to perform analog-to-digital conversion on the receiving terminal charged signals to obtain digital signals; the processor is used to splice the digital signals from the N ADCs based on the first frequency interval to obtain the receiving broadband digital signal.

[0006] In this embodiment, the receiving broadband optical signal is divided into N paths by a beam splitter. These N optical signals undergo photoelectric conversion based on a first frequency interval to obtain receiving terminal electrical signals in different frequency bands. The demodulation frequency bands of the N photoelectric conversion modules are near their corresponding sub-bands, resulting in high demodulation accuracy and low noise introduction for each receiving terminal electrical signal. After the N receiving terminal electrical signals are converted from analog to digital signals, they are spliced ​​together based on the first frequency interval to form a complete receiving broadband digital signal corresponding to the receiving broadband optical signal, thus enabling the reception of the receiving broadband optical signal. In this structure, both the photoelectric conversion module and the ADC are devices whose receiving bandwidth covers the corresponding sub-band. As long as the frequency bands of multiple photoelectric conversion modules / ADCs can be spliced ​​together to form a complete broadband optical / electrical frequency band, the reception of the receiving broadband optical signal can be achieved based on multiple narrow-bandwidth photoelectric conversion modules and ADCs. This improves the receiving optical bandwidth of the optical receiving module even when the bandwidth of the photoelectric conversion module and ADC is limited.

[0007] In one alternative implementation, a synchronous clock circuit is connected to N ADCs; the synchronous clock circuit is used to send trigger signals to the N ADCs at fixed time intervals, the fixed time intervals corresponding to the time difference between the optical path difference between the N ADCs and the beam splitter; the ADCs are used to perform analog-to-digital conversion on the received terminal charged signal under the trigger of the trigger signal.

[0008] In this embodiment, "the fixed time interval corresponds to the time difference between the optical path differences between the N ADCs and the beam splitter" means that the fixed time interval is equal to or approximately equal to the time difference between the optical path differences between the N ADCs and the beam splitter. The interval between the trigger signals sent by the synchronization clock circuit to the N ADCs is stable, and the signals received by the N ADCs have the same signal period.

[0009] If the fixed time interval equals the optical path difference between the splitters, the noise introduced is minimal, and the demodulation effect is optimal. However, due to device limitations or synchronization clock accuracy issues, the fixed time interval may not be exactly equal to the optical path difference between the splitters. In this case, the processor can compensate for the residual difference between a: the fixed time interval and b: the optical path difference locked by the synchronization clock circuit.

[0010] In this embodiment, the ADCs of different channels are controlled by a clock synchronization circuit to sample at fixed time intervals. These fixed time intervals correspond to the optical path difference between different channels, thereby compensating for the link delay of different channels and ensuring that multiple ADCs can synchronously sample different receiving terminal band signals of the same broadband electrical signal at the receiving end.

[0011] In one alternative implementation, the fixed time interval of the synchronous clock circuit is equal to the time difference corresponding to the optical path difference between N ADCs and the beam splitter.

[0012] In one alternative implementation, the fixed time interval of the synchronous clock circuit is approximately equal to the time difference corresponding to the optical path difference between N ADCs and the beam splitter, which is not limited in this application.

[0013] In one alternative implementation, the optical splitter is also used to receive a linear frequency modulated signal, which includes subcarriers of N ADCs corresponding to the frequency bands; the ADCs are used to perform analog-to-digital conversion on the subcarriers of the corresponding frequency bands to obtain digital signals of the corresponding frequency bands; and the processor is used to determine a fixed time interval based on the phase difference and / or frequency difference of the N digital signals from the N ADCs.

[0014] In this embodiment, the link delay on each channel is measured by a linear frequency modulation signal, thereby determining the trigger time interval of each ADC and compensating for the link delay.

[0015] In one optional implementation, the broadband electrical signal corresponding to the broadband optical signal at the receiving end includes the N sub-band electrical signals that are sequentially connected in frequency; the amplitude of the marker signal is higher than the average amplitude of the broadband electrical signal; or, the amplitude of the marker signal is lower than the average amplitude of the broadband electrical signal.

[0016] In this embodiment, the amplitude is used to distinguish between the marker signal and the broadband electrical signal so that the optical receiving module can detect the marker signal.

[0017] In one alternative implementation, among N sub-charged signals connected sequentially in frequency, the frequency intervals of the marker signals of any adjacent sub-charged signals are the same.

[0018] In this embodiment, the frequency intervals of the marker signals are the same, which makes it easier for the processor to identify multiple marker signals and improves processing efficiency.

[0019] In one alternative implementation, each of the N sub-charged signals includes at least one of the aforementioned marker signals.

[0020] In the embodiments of this application, if each sub-charged signal includes a marker signal, the signal reception quality is high; if each sub-charged signal includes multiple marker signals, the failure of a single marker signal can be prevented, thus improving robustness.

[0021] In one optional implementation, the photoelectric conversion module is a coherent receiver, the beam splitter is a power beam splitter, and the optical receiving module also includes a multi-frequency synchronous light source. The power beam splitter is used to divide the received broadband optical signal into N paths according to power and input them to N coherent receivers respectively. The multi-frequency synchronous light source is used to provide frequency-spaced locked coherent light sources for each of the N coherent receivers. The frequencies of the N coherent light sources are different, but the spacing remains stable. The coherent receiver is used to coherently demodulate the optical signal based on the coherent light sources to obtain the received terminal charged signal of the received broadband optical signal (the received terminal charged signal is the result of the optical receiving module's analysis of the corresponding sub-charged signal in the received broadband optical signal).

[0022] In the embodiments of this application, the coherent receiver has advantages such as high sensitivity, anti-dispersion / nonlinearity, flexible spectral efficiency, and support for long-distance transmission, and can receive and process large-capacity communication signals with complex modulation for polarization multiplexing and long-distance transmission.

[0023] Optionally, the coherent receiver may include an optical mixer and an optoelectronic conversion module.

[0024] In one alternative implementation, the frequency spacing of the N coherent light sources is fixed as a first frequency spacing.

[0025] In this embodiment, the frequency spacing of the N coherent light sources is the same as the first frequency spacing, so the processor does not need to shift the frequency of the detected signal, which simplifies the signal processing of the processor and makes the signal processing simple and efficient.

[0026] In one optional implementation, the frequency spacing of the N coherent light sources is fixed as a second frequency spacing that is approximately the same as the first frequency spacing, and the processor is used to calibrate and compensate for the frequency difference between transmission and reception.

[0027] In this embodiment, the frequency interval of the N coherent light sources is not limited to the same as the first frequency interval, which reduces the restriction on the signal and allows for more flexible selection of coherent light sources.

[0028] In one alternative implementation, the multi-frequency synchronous light source includes a laser, a Mach-Zehnder modulator (MZM), and N injection-locked lasers connected in sequence. The laser serves as a seed light source for emitting a light source signal. The MZM generates a comb-shaped light signal based on the light source signal, with the frequency interval of the comb-shaped light signal being a first frequency interval. The injection-locked lasers generate a single-frequency laser that matches their own resonant frequency based on the comb-shaped light signal, with the frequency interval of the single-frequency lasers of the N injection-locked lasers being the first frequency interval.

[0029] In one alternative implementation, the multi-frequency synchronous light source includes an optical frequency comb device and a frequency splitter; the optical frequency comb device is used to generate a comb-shaped optical signal; the frequency splitter is used to connect N coherent receivers, and to divide the comb-shaped optical signal into N optical signals at a first frequency interval, and to input the N optical signals into the corresponding coherent receivers respectively.

[0030] Optionally, the optical frequency comb device may consist of a laser + a micro resonant cavity, or a laser + a fiber Fabry-Pérot loop, or a laser + a cascaded modulator.

[0031] In one optional implementation, the receiving broadband optical signal includes an I-channel optical signal and a Q-channel optical signal; a coherent receiver is used to coherently demodulate the two independent component optical signals I and Q to obtain the sub-band I-channel electrical signal and the sub-band Q-channel electrical signal of the receiving broadband optical signal.

[0032] In this embodiment, the I-channel optical signal and the Q-channel optical signal are coherently demodulated to achieve multiplexing of the I-channel optical signal and the Q-channel optical signal, thereby improving channel capacity and the utilization rate of the optical fiber link.

[0033] In one alternative implementation, N polarization controllers are also included, located between the 1xN beam splitter and the N coherent receivers; the polarization controllers are used to adjust the polarization state of the optical signal from the 1xN beam splitter.

[0034] In one alternative implementation, a polarization controller is also included, located before the 1xN beam splitter; the polarization controller is used to adjust the polarization state of the received broadband optical signal and input the polarization-adjusted received broadband optical signal into the 1xN beam splitter.

[0035] In one optional implementation, the photoelectric conversion module is a photodetector (PD), and the beam splitter is a power beam splitter. The module also includes N filters and N frequency shifters. The frequency spacing of the N filters is consistent with the first frequency spacing. The power beam splitter is connected to the N filters, the N filters are connected to the N frequency shifters one by one, and the N frequency shifters are connected to the N PDs one by one. The power beam splitter is used to divide the received broadband optical signal into N received broadband optical signals according to power, and input the N received broadband optical signals into the N filters respectively. The filters are used to filter the received broadband optical signals to obtain the received terminal band optical signal of the corresponding frequency band. The optical frequency shifter is used to shift the received terminal band optical signal from the filter to the detection range of the PD. The PD is used to perform photoelectric conversion on the frequency-shifted received terminal band optical signal to obtain the received terminal electrical signal of the corresponding frequency band.

[0036] In the embodiments of this application, the photodetector PD has the advantages of simple structure and strong compatibility, and can directly receive short-range, low-complexity communication signals or other simple broadband signals.

[0037] In one optional implementation, there are N sub-band optical signals, including a first sub-band optical signal in the center frequency band and at least one pair of second sub-band optical signals, the frequency of each pair of second sub-band optical signals being centrally symmetrical with respect to the first sub-band optical signal; and the optical signal after frequency shifting of the second sub-band optical signal is located within the detection range of the PD.

[0038] In one optional implementation, the receiving broadband optical signal includes an X-axis polarization component optical signal and a Y-axis polarization component optical signal; a polarization beam splitter is used to split the polarization-multiplexed signal to obtain sub-band X-axis electrical signals and sub-band Y-axis electrical signals of the receiving broadband optical signal.

[0039] In the embodiments of this application, the channel capacity and the utilization rate of the optical fiber link can be improved by multiplexing X-polarization and Y-polarization.

[0040] Secondly, embodiments of this application provide a data transmission method. This data transmission method includes: transmitting a transmitting broadband optical signal, wherein the broadband optical signal corresponds to a broadband electrical signal comprising N sub-band electrical signals sequentially connected in frequency, the frequency interval of the marker signals of the N sub-band electrical signals being fixed as a first frequency interval; the amplitude of the marker signal being higher than the average amplitude of the broadband electrical signal; or, the amplitude of the marker signal being lower than the average amplitude of the broadband electrical signal.

[0041] In this embodiment of the application, the transmitting broadband optical signal is transmitted to the optical receiving module and becomes the receiving broadband optical signal.

[0042] In one alternative implementation, among the N sub-charged signals that are sequentially connected in frequency, any adjacent sub-charged signals have the same frequency interval.

[0043] Thirdly, embodiments of this application provide a detection device, which includes the optical receiving module described in the first aspect.

[0044] Fourthly, embodiments of this application provide an optical communication network, which includes an optical transmitting module and an optical receiving module, wherein the optical receiving module is the optical receiving module described in the first aspect.

[0045] The beneficial effects of the second to fourth aspects are described in the first aspect and will not be repeated here. Attached Figure Description

[0046] Figure 1 A schematic diagram of the optical communication network provided in this application;

[0047] Figure 2 A schematic diagram of the detection device provided in the embodiments of this application;

[0048] Figure 3 A schematic diagram of the structure of an optical receiving module provided in an embodiment of this application;

[0049] Figure 4 A schematic diagram of the sub-band optical signal and the marker signal provided in an embodiment of this application;

[0050] Figure 5 This is another structural schematic diagram of the optical receiving module provided in an embodiment of this application;

[0051] Figure 6 This is another structural schematic diagram of the optical receiving module provided in an embodiment of this application;

[0052] Figure 7 A schematic diagram of a linear modulation signal provided in an embodiment of this application;

[0053] Figure 8 This is another structural schematic diagram of the optical receiving module provided in an embodiment of this application;

[0054] Figure 9a A schematic diagram of the structure of an ICR provided in an embodiment of this application;

[0055] Figure 9b Another structural schematic diagram of the ICR provided in the embodiments of this application;

[0056] Figure 10 This is another structural schematic diagram of the optical receiving module provided in an embodiment of this application;

[0057] Figure 11 A schematic diagram of the transmitting signal provided in an embodiment of this application;

[0058] Figure 12 A schematic diagram of the structure of a multi-frequency synchronous light source provided in an embodiment of this application;

[0059] Figure 13 A schematic diagram of the receiving end acquisition signal provided in an embodiment of this application;

[0060] Figure 14 A schematic diagram of the spliced ​​receiver acquisition signal provided in an embodiment of this application;

[0061] Figure 15 This is another structural schematic diagram of the optical receiving module provided in an embodiment of this application;

[0062] Figure 16 This is another structural schematic diagram of the optical receiving module provided in an embodiment of this application;

[0063] Figure 17 This is another structural schematic diagram of the optical receiving module provided in an embodiment of this application;

[0064] Figure 18 A schematic diagram of a sub-band optical signal provided in an embodiment of this application;

[0065] Figure 19 A schematic diagram of the structure of an optical transmitter provided in an embodiment of this application;

[0066] Figure 20 This diagram illustrates the increasing demand for various optical modules in the wavelength division multiplexing (WDM) network provided in this application embodiment. Detailed Implementation

[0067] The embodiments of this application will now be described with reference to the accompanying drawings. Those skilled in the art will recognize that, with technological advancements and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are equally applicable to similar technical problems.

[0068] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms are interchangeable where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, so that a process, method, system, product, or apparatus that comprises a series of units is not necessarily limited to those units, but may include other units not explicitly listed or inherent to those processes, methods, products, or apparatuses. Additionally, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can be expressed as: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0069] In the field of optical communication, optical signals are received using optical receiver modules. These modules include photoelectric converters and analog-to-digital converters. The photoelectric converter converts optical signals into electrical signals, while the analog-to-digital converter converts electrical signals from analog to digital.

[0070] With the rapid development of AI large-scale models, East-West data computing, and intelligent remote computing, the data traffic in data centers and backbone transmission networks is constantly increasing, leading to a continuous increase in the bandwidth of signals transmitted in optical links. This business scenario places higher demands on the high-speed signal (i.e., high-bandwidth signal) processing capabilities of optical receiving modules and measurement and testing instruments.

[0071] However, current optical receiver modules have limited bandwidth due to the limited bandwidth of photoelectric conversion modules (such as direct detection receivers (PD) and coherent detection receivers (ICR)) and analog-to-digital converters, which restricts the bandwidth of the signals that can be received, thus limiting the increase in the bandwidth of optical signals. Therefore, there is an urgent need for a high-bandwidth optical receiver module to meet the requirements for receiving, measuring, and analyzing high-bandwidth signals.

[0072] To meet the requirements for receiving, measuring, and analyzing high-bandwidth signals, this application provides an optical receiving module. This module divides the received broadband optical signal into multiple signals, acquires the corresponding electrical signals of the received broadband optical signal using a narrowband optoelectronic conversion module and a narrowband analog-to-digital converter, and reconstructs the corresponding electrical signal of the received broadband optical signal by splicing the received terminal electrical signals. Thus, based on the narrowband optoelectronic conversion module and the narrowband analog-to-digital converter, the module achieves the reception of the received broadband optical signal.

[0073] The optical receiver module provided in this embodiment can be applied to... Figure 1 The optical communication network shown can achieve long-distance, high-capacity information transmission. For example... Figure 1 As shown, an optical communication network includes an optical transmitter, relay equipment, and an optical receiver. The optical transmitter modulates a light source according to the electrical signal to be transmitted, obtaining a transmitted optical signal. The relay equipment is used to transmit the transmitted optical signal between the optical transmitter and the optical receiver. The transmitted optical signal (e.g., a transmitted broadband optical signal) is transmitted to the optical receiver, becoming the received optical signal (e.g., a received broadband optical signal). The optical receiver includes a photodetector, demodulation devices, etc., used to convert the received optical signal into an electrical signal, thus enabling signal reception.

[0074] The optical receiving module provided in this application embodiment can be... Figure 1The optical receiver module is used as a high-speed optical module in wavelength division multiplexing (WDM) networks such as data center interconnect (DCI), metropolitan area networks (MANs), and long-haul networks. The optical receiver module converts signals from the optical transmitter into electrical signals, which are then analyzed by a computer to obtain service data. Service data processing can be performed on devices such as computers and computing servers, or it can be done in fields-programmable gate arrays (FPGAs) and digital signal processing (DSP) chips.

[0075] Optionally, the optical receiving module provided in this application embodiment can also be applied to... Figure 2 The test setup shown can be used as a test instrument for optical communication systems. Figure 2 As shown, the test setup includes an optical receiver module and a DSP processing module. The optical receiver module receives optical signals and converts them into electrical signals. The DSP processing module analyzes the electrical signals to determine the quality of the optical signals, demodulate the modulation signal, perform bit error rate analysis, and analyze link impairments.

[0076] Figure 3 This is a schematic diagram of the structure of an optical receiving module provided in an embodiment of this application. Figure 3 As shown, the optical module 3000 includes: a 1xN beam splitter 3100, N photoelectric conversion modules 3200, N analog-to-digital converters (ADCs) 3300, and a processor 3400 (e.g., Figure 3 The digital signal processing module DSP 3400 in the image can also be other types of processors. Here, N is a positive integer, and N≥2. A 1xN beam splitter 3100 is connected to N photoelectric conversion modules 3200, each of the N photoelectric conversion modules 3200 is connected to one of the N ADCs 3300, and each of the N ADCs 3300 is connected to the DSP 3400.

[0077] A 1xN optical splitter 3100 is used to receive a broadband optical signal at the receiving end and split the broadband optical signal into N channels, which are then input to N photoelectric conversion modules 3200. After the 1xN optical splitter 3100, the optical signal is split into N channels, each channel including a photoelectric conversion module 3200 and an ADC 3300.

[0078] The photoelectric conversion module 3200 is used to perform photoelectric conversion on optical signals to obtain the receiving terminal charged signals of the receiving broadband optical signals. N receiving terminal charged signals are connected sequentially in frequency, and the frequency interval of the N receiving terminal charged signals is fixed as the first frequency interval.

[0079] Figure 4This is a schematic diagram of the receiving broadband optical signal in an embodiment of this application. Figure 4 As shown, the receiving broadband optical signal includes N sub-band optical signals connected sequentially in frequency (adjacent sub-band optical signals are separated by dashed lines). Figure 4 (where N is 5). Figure 4 The shorter arrows represent the marker signals of the sub-band optical signals. The amplitude of the marker signals is lower than the average amplitude of the received broadband optical signal (or it may be higher than the average amplitude of the received broadband optical signal; this application does not limit this). The frequency interval of the N sub-band optical signals is the frequency interval of the marker signals of the N sub-band optical signals. The broadband electrical signal corresponding to the received broadband optical signal also includes the aforementioned marker signals. The amplitude relationship of each signal in the broadband electrical signal corresponding to the received broadband optical signal can also be found in [reference needed]. Figure 4 .

[0080] In fact, the number of sub-band optical signals in the broadband optical signal at the receiving end is the same as the number of photoelectric conversion modules 3200 / ADC 3300 in the receiving optical module, which is N. Figure 4 This is merely an example of a broadband optical signal at the receiving end, and... Figure 3 The corresponding receiving broadband optical signal should include two sub-band optical signals.

[0081] In this embodiment of the application, the receiving terminal band signal is the result of the photoelectric conversion module 3200 parsing the corresponding sub-band optical signal in the receiving broadband optical signal. Therefore, the receiving terminal band signal corresponds to the aforementioned sub-band optical signal.

[0082] The ADC 3300 is used to perform analog-to-digital conversion on the received terminal optical signal to obtain a digital signal.

[0083] The DSP 3400 is used to stitch together digital signals from N ADC 3300s based on a first frequency interval to obtain a broadband electrical signal at the receiving end.

[0084] In this embodiment of the application, N can be any positive integer greater than or equal to 2. Figure 3 The example uses N=2, but this does not impose any limitation on N.

[0085] In this embodiment, a 1xN beam splitter 3100 divides the receiving broadband optical signal into N paths. These N optical signals undergo photoelectric conversion based on a first frequency interval to obtain receiving terminal electrical signals in different frequency bands. The demodulation frequency bands of the N photoelectric conversion modules 3200 are near their corresponding sub-bands, resulting in narrow bandwidth and high demodulation accuracy for each receiving terminal electrical signal. After the N receiving terminal electrical signals are converted from analog to digital signals, the DSP 3400 splices the N digital signals based on the first frequency interval, allowing them to be combined into a complete broadband electrical signal corresponding to the receiving broadband optical signal, thereby achieving the reception of the receiving broadband optical signal. In this structure, the photoelectric conversion module 3200 and the ADC 3300 are devices corresponding to subbands. As long as the frequency bands of multiple photoelectric conversion modules 3200 / ADC 3300 can be spliced ​​into a complete broadband optical frequency band / broadband electrical frequency band, the reception of broadband optical signals at the receiving end can be realized based on multiple narrowband photoelectric conversion modules 3200 and ADC 3300. Thus, the receiving optical bandwidth of the optical receiving module 3000 can be improved when the bandwidth of the photoelectric conversion module 3200 and ADC 3300 is limited.

[0086] In this embodiment, N ADCs 3300 are used to perform analog-to-digital conversion on N receiver terminal electrical signals respectively. A 1xN beam splitter 3100 is connected to each optoelectronic conversion module 3200 via optical fiber. Due to the difference in fiber length, there is an optical path difference between the various branch optical paths after the 1xN beam splitter 3100 (i.e., the optical paths from the 1xN beam splitter 3100 to each optoelectronic conversion module 3200). This optical path difference causes the arrival times of the receiver terminal electrical signals of the broadband electrical signal at the corresponding ADC 3300 to be inconsistent. To ensure that multiple ADCs 3300 synchronously sample the different receiver terminal electrical signals of the broadband electrical signal, the sampling time of the ADCs 3300 can be controlled by a synchronization clock circuit.

[0087] In this embodiment of the application, to achieve synchronous sampling of different terminal electrical signals of the receiving broadband electrical signal, two key points need to be addressed: Key point 1, multiple ADCs 3300 need to acquire data stably; Key point 2, accurately measure the signal delay of multiple signals arriving at multiple ADCs 3300, and use algorithms to compensate for the delay differences of multiple signals.

[0088] For key point 1, a synchronous clock circuit can be used to synchronously trigger sampling of multiple ADC 3300s. The corresponding structure is as follows: Figure 5As shown, the synchronous clock circuit 3500 sends trigger signals to N ADCs 3300 at fixed time intervals. These fixed time intervals are equal to the time difference corresponding to the optical path difference between the N ADCs 3300 and the beam splitter 3100 (i.e., the optical path difference between each branch optical path). Only when triggered by the trigger signal does the ADC 3300 perform analog-to-digital conversion on the received terminal signal, thus ensuring that multiple ADCs 3300 stably sample data at fixed time intervals. The sampling time interval compensates for the optical path difference between each branch optical path, thereby enabling the sampling of different received terminal signals of the same broadband electrical signal.

[0089] For key point 2, it can be measured using a linear frequency modulated signal. For example... Figure 6 As shown, a direct connection is made between the transmitting and receiving ends of the optical signal. This reduces dispersion introduced by frequency differences, thereby reducing measurement errors. Then, the signal is transmitted from the transmitting end. Figure 7 The linear frequency modulation signal shown is as follows: Figure 7 As shown in Figure (b), the linear frequency modulated signal is loaded onto different subcarriers and ultimately received in parallel by the optical receiver module 3000. Each ICR (integrated photoelectric conversion module 3200) + ADC 3300 combination in the optical receiver module 3000 receives one of the linear frequency modulated receiving terminal band signals. The signal measured by each ADC 3300 is as follows: Figure 7 As shown in Figure (a), the link delay (i.e., the aforementioned fixed time interval) of multiple branch optical paths (from the beam splitter 3100 to each photoelectric conversion module 3200, also known as different channels) in the optical receiving module 3000 can be measured by the phase difference and / or frequency difference of the linear frequency modulation signal. Based on the measured link delay, the link delay can be compensated by setting the algorithm parameters of the DSP 3400 and the trigger interval of the synchronization clock circuit 3500 for different ADCs 3300.

[0090] In this embodiment, the ADCs of different channels are controlled by a clock synchronization circuit to sample at fixed time intervals. These fixed time intervals correspond to the optical path difference between different channels, thereby compensating for the link delay of different channels and ensuring that multiple ADCs can synchronously sample different receiving terminal band signals of the same broadband electrical signal at the receiving end.

[0091] In this embodiment, the link delay on each channel is measured by a linear frequency modulation signal, thereby determining the trigger time interval of each ADC and compensating for the link delay.

[0092] It is worth noting that, Figure 3 and Figure 5The structure of the optical receiver module 3000 is illustrated using a two-channel configuration (photoelectric conversion module 3200 + ADC 3300) as an example. In practice, the embodiments of this application do not limit the number of channels in the optical receiver module 3000; there can be three, four, or more channels. Considering factors such as miniaturization, cost, heat dissipation, and control complexity, setting two channels within the optical receiver module 3000 is a relatively easy solution to implement.

[0093] Optionally, if the optical path portion of the optical receiver module 3000 is integrated on a chip, it is possible to precisely control that there is no optical path difference between multiple branch optical paths. In this case, the synchronization clock circuit 3500 is not required to trigger each ADC 3300 to sample, and it can still ensure that multiple ADCs 3300 synchronously sample different terminal-charged signals of the broadband electrical signal at the receiving end. This application does not impose any limitations on this.

[0094] Alternatively, by integrating the optical path portion of the optical receiver module 3000 onto the chip, the optical path difference between multiple branch optical paths can be designed in advance. This eliminates the need to detect the optical path difference between each branch optical path, allowing direct determination of the sampling trigger time interval between each ADC 3300.

[0095] In this embodiment, the DSP 3400 splices electrical signals from N ADCs 3300 based on a first frequency interval between the sub-band electrical signals to obtain a receiving broadband electrical signal. This first frequency interval is reflected both in the sampling frequency bands of the different ADCs 3300 and in the receiving broadband optical signal. Figure 8 As shown, the optical receiver module 3000 includes an optical domain signal processing unit, an electrical domain signal processing unit, and a receiver-end DSP processing unit.

[0096] To ensure the correct reception of high-bandwidth signals (broadband optical signals at the receiving end) in the optical receiver module 3000, a single-tone marker signal needs to be added to the signal transmitted from the high-speed transmitter. This marker signal serves as the reference for the local oscillator frequency offset estimation (LOFOE) module. This function is implemented through the transmitter's DSP processing. The high-speed signal is then modulated into the optical frequency range and transmitted to the optical receiver module 3000 via the optical link.

[0097] In the optical domain signal processing unit, the photoelectric conversion module 3200 can be a coherent receiver (ICR). The 1xN beam splitter 3100 is a power beam splitter, and the optical receiver module 3000 also includes a multi-frequency synchronous light source 3600. The received broadband optical signal is split into N paths according to power by the 1xN beam splitter 3100 and then input into N ICRs respectively.

[0098] Before entering the ICR, polarization alignment can be performed using a polarization controller to achieve the highest reception efficiency. Optionally, the frequency offset alignment function of the polarization controller can also be replaced by a DSP 3400. The DSP 3400 performs a polarization state of polarization (SOP) recovery algorithm, which can achieve the same frequency offset alignment effect.

[0099] like Figure 4 As shown, the long arrows indicate the local oscillator signals of different ICRs, which are also the coherent light sources provided by the multi-frequency synchronous light source 3600 for each of the N ICRs. Each signal, after entering an ICR, is coherently combined with the local oscillator signals of different frequencies. Then, in the electrical signal processing unit, it enters different ADCs 3300. At this time, the trigger port of the ADC 3300 is controlled by the synchronous clock circuit 3500 to ensure that it can synchronously receive multiple signals. See also... Figure 6 and Figure 7 The synchronization technology can control the sampling difference between multiple branch optical paths to the picosecond (ps) level. Due to the limited receiving bandwidth of the ADC 3300, a single ADC 3300 only... Figure 4 The signal (charged signal at the receiving end) within a small frequency range is sampled. Finally, after receiving-end digital preprocessing and Rx DSP (DSP 3400) processing, the signals acquired by each ADC 3300 are combined.

[0100] For the DSP processing section at the transmitting end, multiple single-tone marker signals with stable frequency intervals are added to the transmitted signal during signal generation. For example, a broadband signal with a bandwidth of 30GHz is divided into three channels at the receiving end (i.e., three-channel optoelectronic conversion modules 3200 + ADC 3300), dividing the 30GHz bandwidth signal into three 10GHz frequency bands for reception. Single-tone marker signals with frequencies of 5GHz, 15GHz, and 25GHz can be added to the transmitted signal. Thus, at the receiving end (receiving optical module 3000), only the single-tone marker signals detected by channels 1 to 3 need to be spliced ​​together at 10GHz intervals. This ensures that the received 10GHz sub-band signals can be combined into a single complete 30GHz bandwidth signal.

[0101] It should be noted that: ① The number of single-tone marker signals is consistent with the number of photoelectric conversion modules 3200 at the receiving end; ② These single-tone marker signals are not required to be equally spaced, but equally spaced single-tone signals are the easiest to process; ③ The addition of single-tone marker signals with appropriate power will not significantly affect the signal quality at this frequency, because the added single-tone marker signals are added through digital DSP, which only introduces noise at a single frequency point, and has a low impact on the overall signal transmission performance.

[0102] Figure 8 The core of the optical domain signal processing unit shown is to use a frequency-interval-locked optical frequency comb signal as the receiving local oscillator signal for multiple ICRs. Figure 9a Here is a structural diagram of the ICR, such as Figure 9a As shown, the inputs of the ICR are a signal optical port and a local oscillator signal port. The signal optical port is connected to the beam splitter 3100, and the local oscillator optical port is connected to the multi-frequency synchronous light source 3600. The output after passing through the optical mixer (optical hybrid) within the ICR is {E1, E2, E3, E4}. Assume the input signals to the signal optical port and the local oscillator signal port are E... s and E LO Its expression can be written as:

[0103]

[0104] After balanced detection and reception, it can be used to suppress common-mode components while amplifying the beat frequency between the signal light and the local oscillator light. It acquires the photocurrent signals from the I-channel and Q-channel. Its expression can be written as:

[0105]

[0106] Where R is the responsivity of the photodetector.

[0107] Then the local oscillator signal of the ICR of the nth channel can be written as: Where ω n Let be the oscillation frequency of the local oscillator signal of the nth channel. The receiving broadband electrical signal E... s It can be written as: Substituting its expression into the expressions for the photocurrent signals of the I and Q channels above, we can obtain:

[0108]

[0109] It is important to note that: ① The frequency interval of the local oscillator signals of the N ICRs must be relatively stable. This can be achieved in various ways, including optical frequency combs, injection-locked lasers, and harmonic generation. ② Based on the principle of coherent reception, each ICR can only receive one local oscillator signal of a single frequency. If the local oscillator signal has multiple frequencies, it will cause aliasing of the received signals.

[0110] Afterwards, the electrical signal received by the ICR coherent receiver is received by the ADC 3300 at the back end. These ADC 3300s are synchronously sampled based on the trigger signal of the synchronous clock circuit 3500. Each ADC 3300 in each channel only needs to sample the electrical signal within its own bandwidth, and the ADC 3300s in different channels do not need to be of the same specification, and their bandwidth is not limited.

[0111] In this embodiment, the N channels of the optical receiving module 3000 correspond to N local oscillator signals and N sub-band signals. Each sub-band signal may include one or more marker signals. If each sub-band signal includes one marker signal, the signal reception quality is high; if each sub-band signal includes multiple marker signals, it can prevent the failure of a single marker signal and improve robustness.

[0112] Optional, such as Figure 9b As shown, within the ICR, a polarization beam splitter (PBS) and a power beam splitter (BS) may also be included before the optical mixer. The polarization beam splitter is used to split the signal light, and the power beam splitter is used to split the local oscillation (LO) light.

[0113] At the receiving end DSP processing unit, the digital preprocessing subunit performs local oscillator frequency offset estimation (LOFOE) on all sub-band signals acquired by the ADC 3300. This determines the relative frequency of each sub-band signal acquired by the ADC 3300 and filters out overlapping portions of these sub-band signals using digital filtering. Because a calibration signal is added at the transmitting end, aliasing signals can be filtered and reconstructed very accurately. Then, the digital preprocessing subunit performs algorithmic compensation for delay impairments, SOP impairments, and other defects on the multi-channel acquired electrical signals. Finally, the compensated signals are spliced ​​together and sent to the final Rx DSP (DSP3400) algorithm circuit for processing, completing the multi-channel acquisition and analysis of high-speed optical signals.

[0114] In this embodiment, the multi-frequency synchronous light source 3600 may include a laser, a Mach-Zehnder modulator (MZM), and N injection-locked lasers. The corresponding structure is as follows: Figure 10 As shown.

[0115] Taking the coherent reception and analysis of a 100Gbaud optical signal split into two channels as an example, the principle can be extrapolated to 200Gbaud, 300Gbaud, 400Gbaud, and higher baud rates. The bandwidth corresponding to a 100Gbaud signal is generally around 100GHz. If coherent reception is performed through two channels, the bandwidth received by each channel is approximately 50GHz.

[0116] like Figure 11 As shown, the transmitting DSP inserts marker signals into the transmitted signal at 25 GHz and -25 GHz relative to the carrier, respectively. The amplitude of the marker signals is greater than the average amplitude of the transmitted signal. In practical applications, to avoid the marker signals affecting the signal-to-noise ratio (SNR), a marker signal with an amplitude slightly higher than the average is sufficient. Then, a high-speed transmitter generates... Figure 11 The signal is shown and sent, and then transmitted through the optical system.

[0117] The optical signal arrives at the receiver (optical receiver module 3000) and is split into multiple channels for reception by the beam splitter 3100. By fine-tuning the polarization controller, the polarization state of the optical signal is rotated to match the polarization direction inside the ICR, and then it is received separately by the two ICRs.

[0118] Figure 10 The synchronous clock circuit 3500 part in the middle has the following structure: Figure 12 As shown, this is used to generate a group of local oscillator signals with stable frequency intervals. Figure 12 As shown, the synchronous clock circuit 3500 includes Laser0, MZM, coupler, and N injection-locked lasers. The frequency of Laser0 is set to f. 发端 If a 25GHz radio frequency signal is injected into the MZM, a center frequency of f will be generated after the MZM. 发端 A comb-shaped optical signal with a frequency interval of 25 GHz is generated. This comb-shaped optical signal is then injected as seed light into an injection-locked laser (ILL) to generate a regenerated signal. Since the ILLs have different resonant frequencies, each ILL will only select one frequency from the frequency comb (comb-shaped optical signal) for resonant regeneration, thus generating a single-frequency signal. Furthermore, since the N ILLs generate regenerated signals using the same seed signal, the relative frequency intervals of these regenerated signals are stable, and their long-term stability is determined by the long-term stability of the RF signal input to the MZM.

[0119] Note that, for correct signal reception, the local oscillator frequencies of the two ICR channels must satisfy f2-f1=50GHz, (f1+f2) / 2=f 发端Therefore, we can choose the regenerated signal excited by the ±1st harmonic of the comb signal generated after MZM. The two local oscillator frequencies are stabilized at 50GHz to ensure consistency with the transmitting end's marker signal, facilitating the determination of the relative frequency of the received signal during subsequent LOFOE. It should be noted that: ① the interval does not need to be strictly equal to 50GHz, but the frequency interval must be a fixed value that does not change over time. If other frequency values ​​are chosen, frequency errors need to be corrected during subsequent splicing; ② (f1+f2) / 2, which is the center frequency of this set of local oscillator frequencies, should be as consistent as possible with the transmitting end's carrier frequency. For example, here the frequency of Laser0 is chosen as f... 发端 In practice, there may be differences ranging from a few MHz to several GHz, which can be compensated for using a subsequent DSP.

[0120] After coherent reception by ICR, the signals from both frequency bands are coherently received and shifted to the baseband frequency, where they are then acquired by the ADC3300. For example... Figure 13 As shown, the signals acquired by the two ADCs are represented by darker and lighter curves, respectively. It can be seen that the local oscillator signal is near 0 frequency. Because the local oscillator signal selected for the two ICRs basically coincides with the frequency of the single-tone marker signal at the origin, the final acquired marker signal appears near 0 frequency. If other frequencies are selected, the marker signal will appear in other locations. In actual use, the frequency selection of the marker signal is not restricted.

[0121] Because we chose a frequency interval of 50GHz for the marking, we shifted the frequency of the collected signal left and right to obtain the frequency-shifted signal. At this point, the marking signal is... Figure 11 If the signals have the same frequency, it indicates that the signal frequency recovery is complete. It can be seen that the signals acquired by the two ADCs overlap. Since the spectral boundaries of each sub-band signal are known, filtering and compensation can be performed using a digital DSP to compensate for and combine the overlapping spectrum. The final result is... Figure 14 The spectrum shown is the final broadband high-speed signal acquired.

[0122] In this embodiment, the synchronous clock circuit 3500 may include a single-frequency laser, a miniature resonant cavity, and a wavelength selective switch (WSS). The corresponding structure is as follows: Figure 15 As shown.

[0123] like Figure 15As shown, the multi-frequency synchronous light source 3600 can also be implemented using an optical frequency comb + WSS filter scheme. The optical frequency comb (comb-shaped optical signal) can be generated by injecting a single-frequency laser into a micro-resonant cavity. The spacing of the optical frequency comb can be adjusted by designing the geometry and material properties of the micro-resonant cavity, and by changing the refractive index of the cavity material through electro-optic modulation. The generated high-power optical frequency comb is filtered by the WSS, injecting single-frequency signals of different wavelengths into different ICRs, thereby completing multi-channel signal reception.

[0124] It should be noted that: ① There are various methods for generating optical frequency combs, and any method for generating optical frequency combs can be applied to this scenario; ② The method of filtering and splitting the frequency comb signal into multiple paths is not limited to WSS. The same effect can be achieved by using methods such as Bragg gratings.

[0125] In this embodiment, the polarization controller can also be positioned before the beam splitter 3100 (e.g., Figure 16 As shown in the diagram, the polarization-dependent impairments of the signal are compensated for at the back end using an Rx DSP (DSP 3400). If a corresponding polarization restoration algorithm is available, the polarization controller can be removed, and signal reception can still be achieved.

[0126] In the embodiments of this application, besides ICR, the photoelectric conversion module 3200 can also be in the form of a PD. For example... Figure 17 As shown, the photoelectric conversion module 3200 is a photodetector PD, and the 1xN beam splitter 3100 is a power beam splitter. Figure 17 The following explanation uses an example with N=2 channels.

[0127] The optical receiver module 3000 also includes N filters and N optical frequency shifters. The frequency spacing of the N filters is consistent with the first frequency spacing. A power splitter is connected to the N filters, and each of the N filters is connected to one of the N optical frequency shifters. Each of the N frequency shifters is connected to one of the N power distribution units (PDs). The filters, optical frequency shifters, PDs, and ADC 3300 together constitute a channel, for example... Figure 17 The system consists of filter 1, optical frequency shifter 1, PD1, and ADC 3300.

[0128] A power splitter is used to split a receiving broadband optical signal into N receiving broadband optical signals according to power, and then input the N receiving broadband optical signals into N filters respectively.

[0129] The filter is used to filter the received broadband optical signal at the receiver end, obtaining the receiver terminal broadband optical signal in the corresponding frequency band. Different channels of the filter correspond to different frequency bands, and the corresponding spectrum is shown below. Figure 18As shown. For example, taking 4 channels as an example, the receiving broadband optical signal can be divided into 4 receiving subband optical signals, including a first subband optical signal in the center frequency band and at least one pair of second subband optical signals, the frequency of each pair of second subband optical signals being symmetrical with respect to the center of the first subband optical signal.

[0130] In each channel, an optical frequency shifter is used to shift the received terminal band optical signal from the filter of that channel to the detection range of the PD of that channel. The PD is used to perform photoelectric conversion on the frequency-shifted received terminal band optical signal to obtain the received terminal band electrical signal of the corresponding frequency band.

[0131] For example Figure 18 As shown, channel 2 corresponds to the second sub-band optical signal 1, filter 2, frequency shifter 2, and PD2. The broadband optical signal is filtered by filter 2 to obtain the second sub-band optical signal 1. Frequency shifter 2 shifts the second sub-band optical signal 1 to the detection range of the PD. PD2 is used to perform photoelectric conversion on the frequency-shifted second sub-band optical signal 1 to obtain the corresponding sub-band electrical signal. The receiving structure of the optical frequency shifter + PD is essentially a coherent reception of a single-sideband modulated signal.

[0132] Figure 19 This is a schematic diagram of the structure of an optical signal transmitting end provided in an embodiment of this application. Figure 19 As shown, the optical transmitter includes a tagging signal module and an optical transmission module. The optical transmission module is used to acquire the transmitting broadband optical signal based on the transmitting broadband electrical signal, and the tagging signal module is used to add the aforementioned tagging signal to the transmitting broadband electrical signal.

[0133] like Figure 20 As shown, the demand for 800G, 1.6T, and 3.2T optical modules in future wavelength division multiplexing (WDM) networks is rapidly increasing. If the receiving optical module 3000 provided in this embodiment is miniaturized and integrated, it is expected to achieve coherent reception and analysis of high-speed signals at a lower cost and with less technical difficulty. Customer-side service data is transmitted in the WDM network after multiplexing multiplexed optical signals, and is finally received and parsed by the receiving optical module 3000, converting it into service data that can be recognized by the customer-side equipment. The receiving optical module 3000 can perform photoelectric signal conversion and certain DSP processing at the receiving end. Due to the high-bandwidth reception characteristics of the receiving optical module 3000, it can coherently receive signals with high single-wavelength rates, meeting the needs of the above scenarios and possessing certain application potential.

[0134] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0135] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0136] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0137] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0138] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. An optical receiving module, characterized in that, include: A 1xN beam splitter, N photoelectric conversion modules, N analog-to-digital converters (ADCs), and a processor, where N is a positive integer and N≥2; The 1xN beam splitter is connected to the N photoelectric conversion modules, the N photoelectric conversion modules are connected to the N ADCs one by one, and the N ADCs are connected to the processor; The beam splitter is used to split the receiving broadband optical signal into N optical signals, which are then input into the N photoelectric conversion modules respectively. The photoelectric conversion module is used to perform photoelectric conversion on the optical signal to obtain the receiving terminal charged signal of the receiving broadband optical signal. N receiving terminal charged signals are connected sequentially in frequency, and the frequency interval of the marking signal of the N receiving terminal charged signals is fixed as the first frequency interval. The ADC is used to perform analog-to-digital conversion on the received terminal signal to obtain a digital signal; The processor is configured to splice digital signals from the N ADCs based on the first frequency interval to obtain a receiving broadband digital signal.

2. The module of claim 1, wherein, It also includes a synchronous clock circuit, which is connected to the N ADCs; The synchronous clock circuit is used to send trigger signals to the N ADCs at fixed time intervals, the fixed time intervals corresponding to the time difference between the optical path difference between the N ADCs and the beam splitter; The ADC is used to perform analog-to-digital conversion on the received terminal energized signal when triggered by the trigger signal.

3. The module of claim 2, wherein, The optical splitter is also used to receive a linear frequency modulation signal, which includes subcarriers of the corresponding frequency bands of the N ADCs; The ADC is used to perform analog-to-digital conversion on the subcarriers of the corresponding frequency band to obtain the digital signal of the corresponding frequency band; The processor is configured to determine the fixed time interval based on the phase difference and / or frequency difference of the N digital signals from the N ADCs.

4. The module according to any one of claims 1 to 3, characterized in that, The broadband electrical signal corresponding to the broadband optical signal at the receiving end includes N sub-band electrical signals connected sequentially in frequency. The amplitude of the marker signal is higher than the average amplitude of the broadband electrical signal; or, The amplitude of the marker signal is lower than the average amplitude of the broadband electrical signal.

5. The module according to claim 4, characterized in that, Among the N sub-charged signals that are connected sequentially in frequency, the frequency interval of the marker signals of any adjacent sub-charged signals is the same.

6. The module according to any one of claims 1 to 5, characterized in that, Each of the N sub-charged signals includes at least one of the marked signals.

7. The module according to any one of claims 1 to 6, characterized in that, The photoelectric conversion module is a coherent receiver, the beam splitter is a power beam splitter, and the optical receiving module also includes a multi-frequency synchronous light source; The power splitter is used to split the broadband optical signal at the receiving end into N paths according to power and input them into N coherent receivers respectively; The multi-frequency synchronous light source is used to provide coherent light sources for the N coherent receivers respectively, and the N coherent light sources have different frequencies; The coherent receiver is used to coherently demodulate the optical signal based on the coherent light source to obtain the received terminal charged signal of the received broadband optical signal.

8. The module according to claim 7, characterized in that, The frequency interval of the N coherent light sources is fixed as the first frequency interval.

9. The module according to claim 7 or 8, characterized in that, The multi-frequency synchronous light source includes a laser, a Mach-Zehnder modulator (MZM), and N injection-locked lasers connected in sequence. The laser is used to emit light source signals; The MZM is used to generate a comb-shaped light signal based on the light source signal, wherein the frequency interval of the comb-shaped light signal is the first frequency interval; The injection-locked laser is used to generate a single-frequency laser that matches its own frequency based on the comb-shaped light signal, and the frequency interval of the single-frequency lasers of the N injection-locked lasers is the first frequency interval.

10. The module according to claim 7 or 8, characterized in that, The multi-frequency synchronous light source includes an optical frequency comb device and a frequency beam splitter; The optical frequency comb device is used to generate comb-shaped optical signals; The frequency splitter is used to connect the N coherent receivers, and to split the comb-shaped optical signal into N optical signals at the first frequency interval, and to input the N optical signals into the corresponding coherent receivers respectively.

11. The module according to any one of claims 7 to 10, characterized in that, The receiving broadband optical signal includes I-channel optical signal and Q-channel optical signal; The coherent receiver is used to coherently demodulate the optical signal based on the coherent light source to obtain the sub-band I-channel electrical signal and the sub-band Q-channel electrical signal of the receiving broadband optical signal.

12. The module according to claim 11, characterized in that, It also includes N polarization controllers, which are located between the 1xN beam splitter and the N coherent receivers; The polarization controller is used to adjust the polarization state of the optical signal from the 1xN beam splitter.

13. The module according to claim 11, characterized in that, It also includes a polarization controller, which is located before the 1xN beam splitter; The polarization controller is used to adjust the polarization state of the receiving broadband optical signal and input the polarization-adjusted receiving broadband optical signal into the 1xN beam splitter.

14. The module according to any one of claims 1 to 6, characterized in that, The photoelectric conversion module is a photodetector (PD), and the beam splitter is a power beam splitter. The module further includes N filters and N frequency shifters. The frequency spacing of the N filters is consistent with the first frequency spacing. The power splitter is connected to the N filters. The N filters are connected to the N frequency shifters one by one. The N frequency shifters are connected to the N PDs one by one. The power splitter is used to split the receiving broadband optical signal into N receiving broadband optical signals according to the power, and input the N receiving broadband optical signals into N filters respectively. The filter is used to filter the broadband optical signal at the receiving end to obtain the broadband optical signal at the receiving end of the corresponding frequency band. The optical frequency shifter is used to shift the received terminal band optical signal from the filter to the detection range of the PD; The PD is used to perform photoelectric conversion on the frequency-shifted receiver terminal optical signal to obtain the receiver terminal electrical signal of the corresponding frequency band.

15. The module according to claim 14, characterized in that, The N sub-band optical signals include a first sub-band optical signal in the center frequency band and at least one pair of second sub-band optical signals, wherein the frequency of each pair of second sub-band optical signals is symmetrical with respect to the center of the first sub-band optical signal. Furthermore, the optical signal after frequency shifting of the second sub-band optical signal is located within the detection range of the PD.

16. The module according to any one of claims 1 to 15, characterized in that, The receiving broadband optical signal includes X-line polarized light and Y-line polarized light; The photoelectric conversion module is used to perform photoelectric conversion on the optical signal to obtain the sub-band X-channel electrical signal and the sub-band Y-channel electrical signal of the receiving broadband optical signal.

17. A data transmission method, characterized in that, include: A broadband optical signal is transmitted, and the broadband electrical signal corresponding to the broadband optical signal includes N sub-band electrical signals connected sequentially in frequency, wherein the frequency interval of the marker signal of the N sub-band electrical signals is fixed as a first frequency interval. The amplitude of the marker signal is higher than the average amplitude of the broadband electrical signal; or, The amplitude of the marker signal is lower than the average amplitude of the broadband electrical signal.

18. The method according to claim 17, characterized in that, Among the N sub-band signals that are connected sequentially in frequency, any adjacent sub-band signals have the same frequency interval.

19. A detection device, characterized in that, Includes the optical receiving module according to any one of claims 1 to 16.

20. An optical communication network, characterized in that, It includes an optical transmitting module and an optical receiving module, wherein the optical receiving module is the optical receiving module according to any one of claims 1 to 16.

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