Degenerate array optical digitization method based on wavelength division multiplexing

Abstract

In response to the problems of high complexity, great synchronization difficulty, and poor consistency in array digitization systems, the present invention proposes a degenerate array optical digitization method based on wavelength division multiplexing. N optical carriers of different wavelengths are used to load N different analog signals and realize the array acquisition function. The wavelength division multiplexing principle is used to generate the optical sampling clock, and the parallel demultiplexing process is used to achieve degeneration. This method fully utilizes the high parallelism in the wavelength domain to realize a highly simplified array digitization system. The implementation of simplification greatly reduces the complexity of the system. While reducing the redundancy of multi-channel hardware, it improves the consistency and synchronization between multi-channel digital links and enhances the quality of signal conversion. The method has a simple structure and is easy to integrate. It is an effective solution for realizing on-chip high-performance arrayed optical analog-to-digital conversion systems in the future.

Description

Technical Field

[0001] The present invention relates to a photon information processing technology, in particular to a degenerate array optical digitization method based on wavelength division multiplexing. Background Art

[0002] In fields such as radar and wireless communications, the demand for efficient processing of multi-channel, wide-bandwidth signals is becoming increasingly urgent. To meet this demand, digitalization, broadbandization, and array-based transceiver systems have become key technological developments. Unlike analog signals, digital signals are virtually unaffected by noise, attenuation, or distortion, resulting in greater stability and reliability. Digitization converts analog signals into discrete digital signals, making them easier to transmit, store, and process within digital systems. Broadband signals are crucial for improving data transmission rates, optimizing spectrum utilization, enhancing system anti-interference capabilities, and improving signal processing efficiency. Optical digitization technology has garnered widespread attention for its high-speed, wide-bandwidth performance advantages and its application in fields such as high-resolution radar. Optical sampling, quantization-based photonic analog-to-digital conversion systems combine the advantages of photon sampling technology (large bandwidth, low jitter, and high parallelism) with the high quantization accuracy of electronic analog-to-digital converters and have become a mainstream solution in optical digitization systems. However, the evolution of optical digitization systems towards array-based systems still faces numerous challenges, such as high system complexity, stringent synchronization requirements, high integration difficulties, and concerns about size and power consumption. These challenges hinder their continued development into array-based applications.

[0003] The current existing technical solutions cannot meet all the requirements of array digitization. For example, multi-channel electronic analog-to-digital converters face difficult-to-solve crosstalk caused by parasitic inductance and parasitic capacitance [WU Y, LU W, YE F, REN J. Analysis and Cancellation of Crosstalk in Multi-Channel Pipelined-SAR ADCs [C]. 2022 11th International Conference on Communications, Circuits and Systems (ICCCAS): 136-139.]. In order to achieve high reliability, common-mode consistency and other indicators, the design of the analog front end tends to be complicated [Zhu Zhangming, Liu Shubin. Technical challenges and development trends of high-performance analog-to-digital converters [J]. Chinese Science: Information Science, 2024, 54 (01): 48-57.], which further restricts its array development. Therefore, in order to promote the wider application of optical digitization technology in phased array radar, wireless communication, integrated interawareness and other systems, it is urgent to solve the above challenges.

[0004] Patent document CN115840321A discloses a photonic analog-to-digital conversion method and system. By combining passive components such as a continuous laser light source array and a wavelength division multiplexer, the number of active components such as electro-optical modulators in the traditional photonic analog-to-digital conversion system is reduced, thereby reducing the complexity of the system and link loss, and improving the performance of the photonic analog-to-digital conversion system. By simply increasing the number of continuous laser light sources in the continuous laser light source array and the number of channels of the wavelength division multiplexer / demultiplexer, the sampling rate of the photonic analog-to-digital conversion system can be increased exponentially while the single-channel sampling rate of the back-end electronic analog-to-digital converter is fixed, and the system has the ability to be easily expanded on a large scale. However, the invention only proposes a method for improving the sampling rate of the photonic analog-to-digital conversion system based on a continuous laser light source array and a wavelength division multiplexer for the digitization of a single-channel analog signal, and does not propose a solution to the problems of high complexity, low synchronization, poor consistency, large volume and power consumption existing in the digital system for arrayed multi-channel analog signal acquisition. Summary of the Invention

[0005] In response to the problems of high complexity, great synchronization difficulty, and poor consistency in array digitization systems, the present invention proposes a degenerate array optical digitization method based on wavelength division multiplexing. N optical carriers of different wavelengths are used to load N different analog signals and realize the array acquisition function. The wavelength division multiplexing principle is used to generate the optical sampling clock, and the parallel demultiplexing process is used to achieve degeneration. This method fully utilizes the high parallelism in the wavelength domain to realize a highly simplified array digitization system. The implementation of simplification greatly reduces the complexity of the system. While reducing the redundancy of multi-channel hardware, it improves the consistency and synchronization between multi-channel digital links and enhances the quality of signal conversion. The method has a simple structure and is easy to integrate. It is an effective solution for realizing on-chip high-performance arrayed optical analog-to-digital conversion systems in the future.

[0006] The technical solutions of the present invention are as follows:

[0007] The present invention provides a degenerate array optical digitization method based on wavelength division multiplexing, comprising the steps of:

[0008] Generate N optical carriers of different wavelengths, where N ≥ 2;

[0009] Through the principle of wavelength division multiplexing, an optical carrier with N different wavelengths is combined into an optical carrier. The optical carrier with N different wavelengths is modulated electro-optically to generate an optical sampling clock, generating an optical pulse with N different central wavelengths. The repetition frequency of the optical pulse is f s ;

[0010] Using the wavelength division multiplexing principle, one optical pulse with N different central wavelengths is split into N optical pulses with different central wavelengths. N different analog input signals are sampled simultaneously, so that the N optical pulses carry the information of the N analog input signals respectively.

[0011] The sampled optical pulses of N different central wavelengths are combined into one channel, decelerated in the time domain by M-level parallel demultiplexing modules, and decomposed into 2^M parallel channels. Each channel outputs a decelerated optical pulse with N different central wavelengths, with a repetition frequency of f. s / 2^M, where M≥1;

[0012] Extracting the parallel demultiplexed 2^M optical pulses with N different central wavelengths into N optical pulses with different wavelengths according to the differences in the wavelength domain, thereby obtaining 2^M*N optical signals;

[0013] Convert the split 2^M*N optical signals into 2^M*N electrical signals;

[0014] The 2^M*N electrical signals are quantized and encoded into 2^M*N electrical digital signals, and then time domain rearranged in the digital domain to achieve the complete digitization process of the original analog signal.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1) The degenerate array optical digitization method proposed in this invention provides N optical carriers of different wavelengths based on wavelength division multiplexing to carry N inputs of different analog information, realizing unified loading and control of N-channel optical signal multiplexing, consistent timing between channels, and high synchronization. The degenerate system effectively reduces the differences between channels, improves consistency and robustness, and can better adapt to the needs of different environments and working conditions, thereby improving the reliability and accuracy of signal analog-to-digital conversion.

[0017] 2) The degenerate array optical digitization method based on wavelength division multiplexing proposed in this invention maximizes the parallelism of the optical front end, realizes efficient digital processing of multi-channel analog signals based on a set of hardware systems, avoids the problems of high system complexity, high power consumption, and large size caused by multi-channel hardware redundancy, promotes the miniaturization and integration of array digitization systems, and promotes the practical engineering development of optical digitization towards array applications.

[0018] 3) Compared to invention CN115840321A, the wavelength-division multiplexing-based degenerate array optical digitization method proposed in this invention specifically addresses the challenge of efficiently digitizing multiple distinct analog signals. This addresses the challenges of high link complexity and poor consistency during the expansion of multi-channel array digitization systems, which are often overlooked by other single-channel signal digitization solutions. This invention provides array systems with greater scalability and reliability, adapting to the growing array requirements of applications such as phased array radar and wireless communications. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1This is an overall architecture diagram of an embodiment of a degenerate array optical digitization method based on wavelength division multiplexing according to the present invention;

[0020] Figure 2 This is a time domain diagram of combining N optical carriers of different wavelengths into one channel through the principle of wavelength division multiplexing, which describes the time domain independence between optical carriers of different wavelengths.

[0021] Figure 3 (a) Schematic diagram of generating an optical sampling clock by electro-optical modulation of N optical carriers of different wavelengths. Figure 3 (b) Schematic diagram of N optical pulses with different central wavelengths sampling N different analog input signals simultaneously; Figure 3 (c) Schematic diagram of the time domain deceleration of the four-channel output of the sampled single central wavelength optical pulse after passing through the two-stage parallel demultiplexing module; DETAILED DESCRIPTION

[0022] A specific embodiment of the present invention is given below in conjunction with the accompanying drawings. This embodiment is implemented based on the technical solution of the present invention and provides detailed implementation methods and processes, but the protection scope of the present invention is not limited to the following embodiment.

[0023] See Figure 1 , Figure 1This is an overall architecture diagram of an embodiment of a degenerate array optical digitization method based on wavelength division multiplexing of the present invention. As can be seen from the figure, the degenerate array optical digitization method based on wavelength division multiplexing of the present invention includes a continuous light laser array 1, a wavelength division multiplexer 2, an optical sampling clock generation module 3, a wavelength demultiplexer 4, an electro-optical modulator array 5, an analog signal source 6, a wavelength division multiplexer 7, a parallel demultiplexer module 8, a wavelength demultiplexer 9, a photoelectric converter array 10, an electronic analog-to-digital converter array 11 and a digital signal processing module 12. The continuous light laser array is composed of N continuous light laser units arranged in parallel, the electro-optical modulator array is composed of N electro-optical modulators arranged in parallel, the photoelectric converter array 10 is composed of 2^M*N PD units arranged in parallel, and the electronic analog-to-digital converter array 11 is composed of 2^M*N electronic analog-to-digital converters arranged in parallel. The N output ends of the N continuous light laser units 1-1 in the continuous light laser array 1 are respectively connected to the N input ends of the wavelength division multiplexer 2, the output end of the wavelength division multiplexer 2 is connected to the input end of the optical sampling clock generation module 3, the output end of the optical sampling clock generation module 3 is connected to the input end of the wavelength division multiplexer 4, the N output ends of the wavelength division multiplexer 4 are respectively connected to the N first input ends of the N electro-optical modulator units 5-1 in the electro-optical modulator array 5, the analog signal source 6 is respectively connected to the N second input ends of the N electro-optical modulator units 5-1 in the electro-optical modulator array 5, the N output ends of the electro-optical modulator 5 are respectively connected to the N input ends of the wavelength division multiplexer 7, and the output ends of the wavelength division multiplexer 7 are respectively connected to the parallel The input end of the row demultiplexing module is connected, the 2^M output ends of the parallel demultiplexing module are respectively connected to the input ends of the 2^M wave decomposition multiplexers 9, the N output ends of the 2^M*N wave decomposition multiplexers 9 are respectively connected to the 2^M*N input ends of the 2^M*N PD units 10-1 in the photoelectric converter array 10, the output ends of the 2^M*N PD units 10-1 in the photoelectric converter array 10 are respectively connected to the input ends of the 2^M*N electronic analog-to-digital converters 11-1 in the electronic analog-to-digital converter array 11, and the output ends of the 2^M*N electronic analog-to-digital converters 11-1 in the electronic analog-to-digital converter array 11 are respectively connected to the 2^M*N input ends of the digital signal processing module 12, where M≥1 and N≥2.

[0024] The above-mentioned degenerate array optical digitization method based on wavelength division multiplexing includes the following steps:

[0025] 1) If Figure 2 As shown, the continuous light laser array 1 directly generates N optical carriers of different wavelengths which are combined into one beam through the wavelength division multiplexer 2, where N≥2.

[0026] 2) If Figure 3As shown in (a), an optical carrier with N different wavelengths is input into the optical sampling clock generation module 3, generating an optical pulse with N different center wavelengths, with a repetition frequency of fs;

[0027] 3) If Figure 3 As shown in (b), the wavelength division multiplexer 4 splits the optical pulse with N different central wavelengths output by the optical sampling clock generation module 3 into N optical pulses with different central wavelengths according to the differences in the wavelength domain, and inputs them into the N electro-optical modulator units 5-1 of the electro-optical modulator array 5 respectively. The N electro-optical modulators modulate the N different analog signals generated by the analog signal source 6 and load them onto the N optical pulses with different wavelengths. The N optical pulses are then combined into one channel by the wavelength division multiplexer 7.

[0028] 4) If Figure 3 As shown in (c), the output of the wavelength division multiplexer 7 enters the parallel demultiplexing processing module 8. The parallel demultiplexing processing module 8 is mainly composed of cascaded dual-output electro-optical modulators. After the modulation of the driving microwave signal, the repetition frequency of the output optical pulse of each modulator is equal to half of its input optical pulse. After passing through M levels of parallel demultiplexing processing modules 8, the output 2^M channels with a sampling rate of f s / 2^M optical signals, achieving time domain speed reduction processing. The wavelength division multiplexer 9 simultaneously splits each optical signal with N different central wavelengths into N optical signals, obtaining a total of 2^M*N optical signals, where M≥1;

[0029] 5) 2^M*N PD units 10-1 convert the 2^M*N optical signals into 2^M*N electrical signals respectively, and 2^M*N electronic analog-to-digital converters 11-1 quantize and encode the 2^M*N electrical signals into 2^M*N electrical digital signals. Then, the digital signal processing module 12 performs time domain rearrangement on the 2^M*N electrical digital signals in the digital domain, realizing the complete digitization process of the original analog signal.

[0030] The present invention's degenerate array optical digitization method based on wavelength division multiplexing (WDM) significantly simplifies array optical digitization systems by leveraging the principles of WDM. This effectively avoids challenges such as redundant components, high power consumption, poor consistency, and low synchronization, significantly reducing system complexity. By leveraging the principles of WDM, the present invention maximizes the parallelism of the optical front end, significantly expanding the number of array signal acquisition channels in array optical digitization systems. This novel degenerate array optical digitization method offers new possibilities for the development of high-performance, highly integrated array digital acquisition technologies.

Claims

1. A degenerate array optical digitization method based on wavelength division multiplexing, characterized in that: Including steps: Generate N optical carriers of different wavelengths, where N ≥ 2; Through the principle of wavelength division multiplexing, N optical carriers with different wavelengths are combined into one channel, and the optical carriers with N different wavelengths are modulated electro-optically to generate an optical sampling clock, thereby generating an optical pulse with N different central wavelengths, with a repetition frequency of f. s ; Using the wavelength division multiplexing principle, one optical pulse with N different central wavelengths is split into N optical pulses with different wavelengths. The N different analog input signals are sampled simultaneously, so that the optical pulses carry the information of the analog input signals. The N channels of sampled optical pulses with different central wavelengths are combined into one channel, and then decomposed into 2^M parallel channels through M-level parallel demultiplexing modules. The repetition frequency of each channel outputting N optical pulses with different central wavelengths after deceleration is f s / 2^M, where M≥1; The parallel demultiplexed 2^M optical pulses with N different central wavelengths are split into N optical pulses with different wavelengths according to the differences in the wavelength domain, thereby obtaining 2^M*N optical signals; Convert the split 2^M*N optical signals into 2^M*N electrical signals; The 2^M*N electrical signals are quantized and encoded into 2^M*N electrical digital signals, and then time domain rearranged in the digital domain to achieve the complete digitization process of the original analog signal.

2. The degenerate array optical digitization method based on wavelength division multiplexing according to claim 1, characterized in that: The optical carriers with N different wavelengths generate an optical sampling clock by electro-optical modulation, generating an optical pulse with N different center wavelengths, with a repetition frequency of f s , specifically including the steps: N optical carriers with different wavelengths are combined into one optical carrier with N different wavelengths through the wavelength division multiplexing principle; Passing an optical carrier with N different wavelengths into the optical input end of the electro-optical modulator of the optical sampling clock module; The RF drive signal is fed into the RF input of the electro-optical modulator of the optical sampling clock module, so that the repetition frequency of the optical pulse output by the electro-optical modulator is f s .

3. The degenerate array optical digitization method based on wavelength division multiplexing according to claim 1, characterized in that: The N channels of optical pulses with different central wavelengths are used to simultaneously sample N channels of different analog input signals, specifically comprising the following steps: Splitting one optical pulse with N different central wavelengths into N optical pulses with different central wavelengths through the wavelength division multiplexing principle; Passing N optical pulses of different wavelengths into N optical input ports of the N-channel electro-optical modulator of the electro-optical modulation module; Inputting the N analog input signals to be sampled into the N radio frequency input terminals of the N electro-optical modulators of the electro-optical modulation module respectively; N channels of sampled optical pulses with different central wavelengths are combined into one channel of sampled optical pulses with N different wavelengths through the wavelength division multiplexing principle.

4. The degenerate array optical digitization method based on wavelength division multiplexing according to claim 1, characterized in that: The method of combining N channels of sampled optical pulses with different central wavelengths into one channel and performing time domain speed reduction processing through M-level parallel demultiplexing modules specifically includes the following steps: N channels of sampled optical pulses with different central wavelengths are combined into one channel of sampled optical pulses with N different wavelengths through the wavelength division multiplexing principle; Inputting a channel of sampled optical pulses with N different central wavelengths into the optical input end of the cascaded dual-output electro-optical modulator of the parallel demultiplexing module; The RF drive signal is passed to the RF input of each cascaded dual-output electro-optical modulator of the M-level parallel demultiplexing module. The frequency of the RF drive signal of each dual-output electro-optical modulator is equal to the repetition frequency of the optical pulse output from itself. In the order of cascade, the frequencies are f s / 2, f s / 4……f s / 2^M, where M≥1.

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