Coherent optical communication system integrated with electro-optic frequency comb driver

Abstract

This invention belongs to the field of optical communication technology and discloses a coherent optical communication system driven by an integrated electro-optic frequency comb, comprising: a continuous wave laser (1), an electro-optic frequency comb chip (2), a radio frequency signal source (3), a radio frequency signal distribution module (4), a first fiber amplifier (5), an arbitrary waveform generator (6), a dual-polarization in-phase quadrature modulator (7), a second fiber amplifier (8), a single-mode fiber (9), a third fiber amplifier (10), a tunable bandpass filter (11), a local oscillator continuous wave laser (12), a coherent receiver (13), and an offline digital signal processing module (14); wherein, the electro-optic frequency comb chip (2) is loaded with a radio frequency signal and can perform electro-optic modulation on the continuous wave optical signal to generate a broadband, flat-top electro-optic frequency comb. By integrating an electro-optic frequency comb chip into the coherent optical communication system, this invention can significantly improve the system integration and greatly reduce the system cost.

Description

Technical Field

[0001] This invention belongs to the field of optical communication technology, and more specifically, relates to a coherent optical communication system driven by an integrated electro-optic frequency comb. Background Technology

[0002] The current era of big data has created a significant demand for increasing communication bandwidth and reducing system energy consumption in data centers. Wavelength division multiplexing (WDM) optical communication technology, which uses light waves as its carrier, has been extensively researched and developed. Current WDM optical communication systems use an array of multiple independent lasers as the light source, with each laser providing an optical signal for a specific channel. This design requires ensuring relatively stable frequency and phase relationships between the lasers, while also minimizing quality differences between the signals from different channels. Furthermore, since each laser requires its own hardware and control system, the system's energy consumption and cost are relatively high. Moreover, this structure cannot achieve dynamic adjustment of channel spacing, limiting the system's scalability and flexibility.

[0003] Optical frequency combs, composed of multiple comb teeth with equal frequency spacing and stable phase relationships, have become a promising alternative light source in WDM systems. Mode-locked laser-based optical comb systems are large in size, and their wavelength range is limited by the gain spectrum of the gain medium; Kerr combs based on the Kerr effect in microcavities exhibit a roll-off spectrum, and the tooth spacing is difficult to tune effectively.

[0004] The integrated electro-optic frequency comb, with its advantages such as spectral flatness, stability, and adjustable comb spacing, holds promise as a replacement for traditional multi-laser arrays as a multi-wavelength light source in WDM optical communication systems. This would reduce system architecture complexity and improve channel consistency. However, achieving efficient generation and precise control of the integrated electro-optic frequency comb, and effectively integrating it with coherent optical communication systems to fully leverage its potential in multi-channel carrying and high-speed transmission, thereby constructing a high-capacity, high-speed, and highly integrated optical communication system, remains a critical issue that urgently needs to be addressed. Summary of the Invention

[0005] In view of the above-mentioned defects or improvement needs of the existing technology, the purpose of this invention is to provide a coherent optical communication system driven by an integrated electro-optic frequency comb. By improving the various components of the system and their cooperative working methods, an electro-optic frequency comb chip is integrated into the system. Compared with the traditional solution of using a laser array as a light source, this can significantly improve the system integration and greatly reduce the system cost.

[0006] To achieve the above objectives, according to a first aspect of the present invention, an integrated electro-optic frequency comb driven coherent optical communication system is provided, characterized in that it comprises: a continuous wave laser (1), an electro-optic frequency comb chip (2), a radio frequency signal source (3), a radio frequency signal distribution module (4), a first fiber amplifier (5), an arbitrary waveform generator (6), a dual polarization in-phase quadrature modulator (7), a second fiber amplifier (8), a single-mode fiber (9), a third fiber amplifier (10), a tunable bandpass filter (11), a local oscillator continuous wave laser (12), a coherent receiver (13), and an offline digital signal processing module (14). The continuous wave laser (1) is used to generate a wavelength-tunable continuous wave optical signal and can simultaneously output one or more continuous wave optical signals with different center wavelengths; the radio frequency signal generated by the radio frequency signal source (3) is loaded onto the electro-optic frequency comb chip (2) via the radio frequency signal distribution module (4); the electro-optic frequency comb chip (2) is used to electro-optically modulate the continuous wave optical signal to generate a broadband, flat-top electro-optic frequency comb, thus obtaining the light source for the WDM system; the first fiber amplifier (5) is used to amplify the electro-optic frequency comb and serve as the light source for the coherent optical communication system; the arbitrary waveform generator (6) is used to provide a modulation signal for the dual polarization in-phase quadrature modulator (7), and the dual polarization in-phase quadrature modulator (7) is used to load the modulation signal onto multiple comb teeth of the electro-optic frequency comb, thus obtaining... The optical signal is transmitted via a fiber amplifier; the second fiber amplifier (8) is used to amplify the transmitted optical signal; the single-mode fiber (9) is used to transmit the optical signal over a preset distance; the third fiber amplifier (10) is used to amplify the optical signal transmitted via the single-mode fiber (9); the tunable bandpass filter (11) is used to perform channel selection on the optical signal output by the third fiber amplifier (10) and filter out the modulated single comb signal; the local oscillator continuous wave laser (12) is used to generate the local oscillator optical signal; the coherent receiver (13) is used to perform coherent detection on the local oscillator optical signal and the filtered comb signal to obtain an electrical signal; the offline digital signal processing module (14) is used to perform digital signal processing on the electrical signal to recover the data information carried by the optical signal.

[0007] As a further preferred embodiment of the present invention, the electro-optic frequency comb chip (2) includes a cascaded intensity modulator and a phase modulator; the phase modulator may be one or more.

[0008] As a further preferred embodiment of the present invention, both the intensity modulator and the phase modulator are electro-optic modulators based on a thin-film lithium niobate platform.

[0009] As a further preferred embodiment of the present invention, the type of the phase modulator is selected from a straight waveguide phase modulator, a cyclic phase modulator, and a folded phase modulator.

[0010] As a further preferred embodiment of the present invention, the intensity modulator is used to intensity modulate the continuous wave optical signal to generate a narrowband, flat-top electro-optic frequency comb, and the phase modulator is used to phase modulate the narrowband, flat-top electro-optic frequency comb to generate the broadband, flat-top electro-optic frequency comb.

[0011] As a further preferred embodiment of the present invention, the first fiber amplifier (5), the second fiber amplifier (8) and the third fiber amplifier (10) are all polarization-maintaining erbium-doped fiber amplifiers; The continuous wave laser (1) is one or more, and simultaneously serves as a light source input to the electro-optic frequency comb chip (2); The single-mode fiber (9) is a standard communication single-mode fiber.

[0012] According to a second aspect of the present invention, the present invention provides a method for using the above-mentioned integrated electro-optic frequency comb driven coherent optical communication system, characterized in that the frequency of the radio frequency signal output by the radio frequency signal source (3) is adjusted to achieve the tuning of the spacing between the comb teeth of the electro-optic frequency comb, thereby tuning the channel spacing of the coherent optical communication system.

[0013] According to a third aspect of the present invention, the present invention provides a method of using the above-mentioned integrated electro-optic frequency comb driven coherent optical communication system, characterized in that, by adjusting the power and phase of the radio frequency signal loaded by the radio frequency signal distribution module (4) onto each modulator on the electro-optic frequency comb chip (2), the flatness and number of comb teeth of the electro-optic frequency comb are tuned, so that the flatness fluctuation of the electro-optic frequency comb does not exceed 10 dB, and the number of channels of the optical communication system is tuned.

[0014] According to a fourth aspect of the present invention, the present invention provides a method for using the above-mentioned integrated electro-optic frequency comb driven coherent optical communication system, characterized in that a baseband or radio frequency signal with a corresponding preset modulation format is generated by adjusting an arbitrary waveform generator (6), thereby realizing the reconstruction of the modulation format and transmission rate in the optical communication system.

[0015] According to a fifth aspect of the present invention, the present invention provides a method of using the above-described integrated electro-optic frequency comb driven coherent optical communication system, characterized in that when the continuous wave laser (1) outputs only a continuous wave optical signal with a center wavelength, the electro-optic frequency comb chip (2) is able to generate an electro-optic frequency comb with a center wavelength. When the continuous wave laser (1) outputs multiple continuous wave optical signals with different center wavelengths at the same time, the electro-optic frequency comb chip (2) can generate multiple electro-optic frequency combs with multiple center wavelengths, thereby expanding the number of channels in the coherent optical communication system.

[0016] Compared with the prior art, the above technical solution conceived by this invention uses radio frequency signals to drive an electro-optic frequency comb chip to generate a broadband, flat electro-optic frequency comb, which serves as the light source for a WDM system. The electro-optic frequency comb is amplified by a first fiber amplifier and then input to a dual polarization in-phase quadrature modulator to load a modulation signal. Subsequently, it is amplified by a second fiber amplifier, transmitted through a fiber optic cable of a preset distance, amplified by a third fiber amplifier, and received by the receiving end.

[0017] Specifically, the present invention can achieve the following beneficial effects: 1. This invention uses a broadband, flat-top electro-optic frequency comb generated by an electro-optic frequency comb chip as the light source for a WDM system. Compared to the traditional approach using a laser array as the light source, this invention can obtain multiple channels even using only one continuous-wave laser as the seed light, significantly improving system integration and greatly reducing system cost (of course, to further expand the number of channels, this invention can also use multiple continuous-wave lasers as seed lights). The optical signal output from the continuous-wave laser enters the RF signal-driven electro-optic frequency comb chip to generate a broadband, flat-top electro-optic frequency comb, which serves as the light source for the coherent optical communication system. After the electro-optic frequency comb is loaded with data signals by a dual-polarization in-phase quadrature modulator, it is transmitted via an optical fiber link, and the data information is recovered at the receiving end through coherent detection and digital signal processing.

[0018] 2. This invention uses the same electro-optic frequency comb light source to provide a carrier for the coherent optical communication system. When only one continuous wave laser is used as the seed light, each channel is generated by the same light source, which avoids the frequency drift and consistency differences between different light sources in the laser array scheme. This helps to simplify the system calibration and maintenance process and improve the long-term operational stability and engineering implementation reliability of the coherent optical communication system.

[0019] 3. This invention uses a radio frequency (RF) signal source and an RF signal distribution module to generate a single-frequency RF signal, which is then applied to an electro-optic frequency comb chip. By modulating the power and phase of the applied RF signal, the electro-optic frequency comb chip can generate a broadband, flat-top electro-optic frequency comb (flatness fluctuation, for example, not exceeding 10 dB), without the need for shaping. This invention achieves flexible tuning of the channel spacing in the communication system by adjusting the frequency of the RF signal applied to the electro-optic frequency comb chip; by adjusting the power and phase of the RF signals of each modulator applied to the electro-optic frequency comb chip, it achieves tuning of the flatness and number of comb teeth of the electro-optic frequency comb. Tuning the number of comb teeth, in turn, tunes the number of channels, while minimizing flatness fluctuations ensures minimal quality differences between channels, thereby improving the reconfigurability of the light source. Furthermore, by simultaneously injecting multiple continuous-wave lasers as input light into the electro-optic frequency comb chip, the number of channels of the electro-optic frequency comb can be further expanded, which is beneficial for improving the transmission rate of coherent optical communication systems.

[0020] This invention enables the tuning of the electro-optic frequency comb's tooth spacing and number of teeth by adjusting the frequency, power, and phase of the radio frequency signal, as well as the number of center wavelengths output by the continuous wave laser. This, in turn, allows for the tuning of channel parameters in a coherent optical communication system. This invention improves system integration and reconfigurability, reduces system costs, and is suitable for high-speed coherent optical communication applications.

[0021] In summary, compared with traditional WDM systems, this invention has advantages in system integration, channel spacing tunability, and system cost. The coherent optical communication system driven by the integrated electro-optic frequency comb in this invention, by applying the integrated electro-optic frequency comb to the WDM system, can improve system integration and reconfigurability while increasing the communication capacity and rate of the coherent optical communication system and reducing system implementation costs. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a coherent optical communication system driven by an integrated electro-optic frequency comb in an embodiment of the present invention.

[0023] Figure 2 These are the original electro-optic frequency comb spectrum with a comb tooth spacing of 25 GHz and the partial electro-optic frequency comb spectrum modulated by a signal in a 24.5 Gbaud PM 16-QAM modulation format in Embodiment 1 of the present invention; wherein, Figure 2 (a) in the spectrum corresponds to the original electro-optic frequency comb spectrum. Figure 2 (b) in the spectrum corresponds to the modulated electro-optic frequency comb.

[0024] Figure 3 This includes the bit error rate (BER) analysis results of the 1550 nm channel in the electro-optic frequency comb loaded with a 24.5 Gbaud PM 16-QAM modulated signal in Embodiment 1 of the present invention, when the transmitting and receiving ends are connected back-to-back (B2B) and connected via a 20 km single-mode fiber; the constellation diagram when the received optical power is -12 dBm; and the BER analysis results of each channel. Figure 3 (a) in the table corresponds to the bit error rate analysis results. Figure 3 (b) in the diagram corresponds to the constellation diagram when the received optical power is -12 dBm. Figure 3 (c) in the figure corresponds to the bit error rate analysis results of 62 channels after transmission through 20 km of single-mode fiber.

[0025] Figure 4The present invention relates to a dual-broadband electro-optic frequency comb in Embodiment 2, wherein the comb tooth spacing is 25 GHz and the center wavelengths are 1545 nm and 1555 nm, respectively. It also includes the bit error rate analysis results for 86 channels after the electro-optic comb, loaded with a 24.5 Gbaud PM 16-QAM modulation signal, is transmitted through 20 km single-mode fiber. Figure 4 (a) in the spectrum corresponds to the dual broadband electro-optic frequency comb spectrum. Figure 4 (b) in the table corresponds to the bit error rate analysis results for 86 channels. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other. Moreover, the technical features involved in the embodiments of this invention described below can be replaced with other devices or modules with the same function.

[0027] The coherent optical communication system driven by the integrated electro-optic frequency comb in this invention uses the electro-optic frequency comb chip to generate an electro-optic comb as the light source of the WDM system. After amplification, a modulated signal is loaded, amplified again, transmitted through a certain length of single-mode optical fiber, amplified again, and received by a coherent receiver.

[0028] like Figure 1 As shown, the integrated electro-optic frequency comb driven coherent optical communication system includes: a continuous wave laser 1, an electro-optic frequency comb chip 2, a radio frequency signal source 3, a radio frequency signal distribution module 4, a first fiber amplifier 5, an arbitrary waveform generator 6, a dual polarization in-phase quadrature modulator 7, a second fiber amplifier 8, a single-mode fiber 9, a third fiber amplifier 10, a tunable bandpass filter 11, a local oscillator continuous wave laser 12, a coherent receiver 13, and an offline digital signal processing module 14.

[0029] The output terminal of the radio frequency signal source 3 is connected to the input terminal of the radio frequency signal distribution module 4. The radio frequency signal source 3 is used to generate radio frequency signals. The output terminal of the RF signal distribution module 4 is connected to the electrical input terminal of the electro-optic frequency comb chip 2. The RF signal distribution module 4 is used to load RF signals onto the electro-optic frequency comb chip 2 (that is, the RF signal distribution module 4 is used to distribute RF signals to each modulator in the electro-optic frequency comb chip 2, and the power and phase of each RF signal can be adjusted). The continuous wave laser 1 is connected to the optical input terminal of the electro-optic frequency comb chip 2. The continuous wave laser 1 is used to generate a wavelength-tunable continuous wave optical signal and can simultaneously output one or more continuous wave optical signals with different center wavelengths as input light injected into the electro-optic frequency comb chip. The optical output end of the electro-optic frequency comb chip 2 is connected to the input end of the first fiber amplifier 5, which is used to amplify the electro-optic comb generated by the electro-optic frequency comb chip 2. The output end of the first fiber amplifier 5 is connected to the optical input end of the dual polarization in-phase quadrature modulator 7, which is used to load the modulation signal onto the electro-optic frequency comb. The signal output by the arbitrary waveform generator 6 is loaded onto the dual polarization in-phase quadrature modulator 7. The arbitrary waveform generator 6 is used to generate a baseband or radio frequency signal corresponding to a preset modulation format (that is, the arbitrary waveform generator 6 is used to generate a modulation signal, which provides the dual polarization in-phase quadrature modulator 7 with modulation signals of different formats). The optical output end of the dual polarization in-phase quadrature modulator 7 is connected to the input end of the second fiber amplifier 8, which is used to amplify the modulated electro-optic frequency comb. The output of the second fiber amplifier 8 is connected to the input of the single-mode fiber 9, which is used to simulate a transmission link at a preset distance. The output end of the single-mode fiber 9 is connected to the input end of the third fiber amplifier 10, which is used to amplify the optical signal transmitted through the single-mode fiber 9. The output of the third fiber amplifier 10 is connected to the input of the tunable bandpass filter 11. The tunable bandpass filter 11 is used to perform channel selection on the modulated electro-optic frequency comb and filter out individual comb tooth signals. The local oscillator continuous wave laser 12 is connected to the first input terminal of the coherent receiver 13. The local oscillator continuous wave laser 12 is used to generate a local oscillator optical signal for the coherent receiver 13 to perform coherent detection (the local oscillator optical signal serves as the reference light for coherent detection). The output terminal of the tunable bandpass filter 11 is connected to the second input terminal of the coherent receiver 13. The coherent receiver 13 is used to perform coherent detection on the received optical signal to obtain an electrical signal. The output of the coherent receiver 13 is connected to the offline digital signal processing module 14; the offline digital signal processing module 14 is used to perform digital signal processing on the electrical signal to recover the data information carried by the optical signal and extract the bit error rate and constellation diagram of the channel.

[0030] The following are specific examples: Example 1 In this embodiment, a continuous-wave laser 1 generates a 1550 nm optical signal, and a radio frequency signal source 3 generates a 25 GHz modulation signal. The modulation format of the dual-polarization in-phase quadrature modulator 7 is 24.5 Gbaud PM 16-QAM, and the length of the single-mode fiber 9 is 20 km. The optical power after amplification by the first fiber amplifier 5 is approximately 17.8 dBm, the optical power after amplification by the second fiber amplifier 8 is approximately 10 dBm, and the optical power after amplification by the third fiber amplifier 10 is approximately 20 dBm. The electro-optic frequency comb chip is fabricated using thin-film lithium niobate material and includes a cascaded intensity modulator and two straight waveguide phase modulators (similar to the conventional definition, a straight waveguide phase modulator refers to a conventional phase modulation structure in which the optical signal propagates along a single straight waveguide without loops or folded paths), with an insertion loss of 15 dB. The half-wave voltage of the phase modulator at 25 GHz is 2.5 V. The first, second, and third fiber amplifiers are all polarization-maintaining erbium-doped fiber amplifiers.

[0031] In this example, a 25 GHz radio frequency signal is used to drive the electro-optic frequency comb chip 2 to generate the electro-optic comb spectrum, such as... Figure 2 As shown in (a) above; the partial spectrum of the electro-optical comb after loading a 24.5 Gbaud PM 16-QAM modulated signal through a dual-polarization in-phase quadrature modulator 7, as shown in (a). Figure 2 As shown in (b) of the diagram. Figure 2 As shown in (a), a 25 GHz radio frequency signal is applied to the optical signal output from the continuous wave laser 1 via an electro-optic frequency comb chip 2, generating a flat, broadband electro-optic comb with a repetition frequency of 25 GHz. Furthermore, as... Figure 2 As shown in (a), within a 10 dB flatness range, each peak corresponds to one channel, for a total of 62 channels, corresponding to a transmission rate of 12.15 Tb / s. Figure 2 As shown in (b), the resulting flat, broadband electro-optical comb produces small sidebands near the comb teeth after being loaded with a 24.5 Gbaud PM 16-QAM modulation signal by a dual polarization in-phase quadrature modulator 7.

[0032] In this embodiment, the bit error rate analysis results of the 1550 nm channel in the electro-optic frequency comb spectrum after loading the modulation signal are as follows: (B2B connection at the transmitter and receiver and connection via single-mode fiber 9) Figure 3 As shown in (a) above; constellation diagram of the 1550 nm channel in the modulated electro-optic comb spectrum when connected via B2B at the transmitter and receiver and via single-mode fiber 9, as shown below. Figure 3 As shown in (b) of the figure; the bit error rate of each channel in the electro-optic comb spectrum after loading the modulated signal, when connected in B2B connection at the transmitter and receiver and connected via single-mode fiber 9, as shown in the figure. Figure 3As shown in (c) in the diagram. Figure 3 As shown in (a), the bit error rate of the 1550 nm channel in the electro-optic comb spectrum after loading the modulated signal was measured at the transmitter and receiver B2B connection and via a 20 km single-mode fiber 9 connection; Figure 3 As shown in (b), the constellation diagram corresponding to a received optical power of -12 dBm was measured; Figure 3 As shown in (c), the bit error rate of the 62 channels of the electro-optic frequency comb after the modulation signal was applied was measured when the transmitter and receiver were connected in a B2B connection and when connected via a 20 km single-mode fiber 9.

[0033] Example 2 This embodiment specifically uses 1545 nm and 1555 nm optical signals generated by a continuous wave laser 1 and a 25 GHz modulation signal generated by a radio frequency signal source 3. The modulation format of the dual-polarization in-phase quadrature modulator 7 is 24.5 Gbaud PM 16-QAM, and the length of the single-mode fiber 9 is 20 km. The optical power after amplification by the first fiber amplifier 5 is 17.8 dBm, the optical power after amplification by the second fiber amplifier 8 is 10 dBm, and the optical power after amplification by the third fiber amplifier 10 is 20 dBm. The electro-optic frequency comb chip is fabricated using thin-film lithium niobate material and includes a cascaded intensity modulator and two straight waveguide phase modulators (similar to the conventional definition, a straight waveguide phase modulator refers to a conventional phase modulation structure in which the optical signal propagates along a single straight waveguide without loops or folded paths), with an insertion loss of 15 dB. The half-wave voltage of the phase modulator at 25 GHz is 2.5 V. The first, second, and third fiber amplifiers are all polarization-maintaining erbium-doped fiber amplifiers.

[0034] In this example, two continuous wave lights of different wavelengths are used as input light, and a 25 GHz radio frequency signal is used to drive the electro-optic frequency comb chip 2 to generate a dual broadband electro-optic frequency comb spectrum, such as... Figure 4 As shown in (a) above; the bit error rate analysis results of the dual broadband electro-optic frequency comb after being loaded with a 24.5 Gbaud PM 16-QAM modulated signal and transmitted through a single-mode fiber 9 are as follows. Figure 4 As shown in (b) in the figure; and, as Figure 4 As shown in (a), within a 10 dB flatness range, each peak corresponds to one channel, for a total of 86 channels, corresponding to a transmission rate of 16.85 Tb / s. Figure 4 As shown in (a), a 25 GHz radio frequency signal is applied to the optical signals output by the continuous wave laser 1, with center wavelengths of 1545 nm and 1555 nm respectively, via an electro-optic frequency comb chip 2, generating a dual broadband electro-optic frequency comb with a repetition frequency of 25 GHz; Figure 4 As shown in (b), the bit error rate of the electro-optical comb after being loaded with a 24.5 Gbaud PM 16-QAM modulated signal and transmitted through a 20 km single-mode fiber 9 was measured.

[0035] The above embodiments are merely examples. For instance, the electro-optic frequency comb chip based on the thin-film lithium niobate platform in the above embodiments can also be constructed using other optoelectronic materials with similar functions, in addition to thin-film lithium niobate. The flat-top electro-optic frequency comb in this invention, similar to conventional requirements, needs to maintain small fluctuations in the output optical power of each comb tooth within the effective operating bandwidth, thereby facilitating balanced modulation of each channel in the coherent optical communication system and improving the overall system performance. Furthermore, the transmission distance of single-mode fiber can be flexibly adjusted according to actual needs. The solution of this invention is applicable to any distance, whether it is long-distance optical communication >100 km, or application scenarios for metropolitan area networks (10~100 km) and data centers (<10 km). Moreover, in addition to straight waveguide phase modulators, the phase modulator can also be a cyclic phase modulator or a folded phase modulator.

[0036] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An integrated electro-optical frequency comb driven coherent optical communication system, characterized by, include: Continuous wave laser (1), electro-optic frequency comb chip (2), radio frequency signal source (3), radio frequency signal distribution module (4), first fiber amplifier (5), arbitrary waveform generator (6), dual polarization in-phase quadrature modulator (7), second fiber amplifier (8), single-mode fiber (9), third fiber amplifier (10), tunable bandpass filter (11), local oscillator continuous wave laser (12), coherent receiver (13) and offline digital signal processing module (14); The continuous wave laser (1) is used to generate a wavelength-tunable continuous wave optical signal and can simultaneously output one or more continuous wave optical signals with different center wavelengths; the radio frequency signal generated by the radio frequency signal source (3) is loaded onto the electro-optic frequency comb chip (2) via the radio frequency signal distribution module (4); the electro-optic frequency comb chip (2) is used to electro-optically modulate the continuous wave optical signal to generate a broadband, flat-top electro-optic frequency comb, thus obtaining the light source for the WDM system; the first fiber amplifier (5) is used to amplify the electro-optic frequency comb and serve as the light source for the coherent optical communication system; the arbitrary waveform generator (6) is used to provide a modulation signal for the dual polarization in-phase quadrature modulator (7), and the dual polarization in-phase quadrature modulator (7) is used to load the modulation signal onto multiple comb teeth of the electro-optic frequency comb, thus obtaining... The optical signal is transmitted via a fiber amplifier; the second fiber amplifier (8) is used to amplify the transmitted optical signal; the single-mode fiber (9) is used to transmit the optical signal over a preset distance; the third fiber amplifier (10) is used to amplify the optical signal transmitted via the single-mode fiber (9); the tunable bandpass filter (11) is used to perform channel selection on the optical signal output by the third fiber amplifier (10) and filter out the modulated single comb signal; the local oscillator continuous wave laser (12) is used to generate the local oscillator optical signal; the coherent receiver (13) is used to perform coherent detection on the local oscillator optical signal and the filtered comb signal to obtain an electrical signal; the offline digital signal processing module (14) is used to perform digital signal processing on the electrical signal to recover the data information carried by the optical signal.

2. The integrated electro-optical frequency comb driven coherent optical communication system of claim 1, wherein, The electro-optic frequency comb chip (2) includes cascaded intensity modulators and phase modulators; the phase modulators are one or more.

3. The coherent optical communication system driven by the integrated electro-optic frequency comb according to claim 2, characterized in that, Both the intensity modulator and the phase modulator are electro-optic modulators based on a thin-film lithium niobate platform.

4. The coherent optical communication system driven by the integrated electro-optic frequency comb according to claim 2, characterized in that, The phase modulator is selected from straight waveguide phase modulators, cyclic phase modulators, and folded phase modulators.

5. The coherent optical communication system driven by the integrated electro-optic frequency comb according to claim 2, characterized in that, The intensity modulator is used to intensity modulate the continuous wave optical signal to generate a narrowband, flat-top electro-optic frequency comb, and the phase modulator is used to phase modulate the narrowband, flat-top electro-optic frequency comb to generate the broadband, flat-top electro-optic frequency comb.

6. The coherent optical communication system driven by the integrated electro-optic frequency comb according to claim 1, characterized in that, The first fiber amplifier (5), the second fiber amplifier (8) and the third fiber amplifier (10) are all polarization-maintaining erbium-doped fiber amplifiers; The continuous wave laser (1) is one or more, and simultaneously serves as a light source input to the electro-optic frequency comb chip (2); The single-mode fiber (9) is a standard communication single-mode fiber.

7. The method of using the coherent optical communication system driven by the integrated electro-optic frequency comb as described in any one of claims 1-6, characterized in that, By adjusting the frequency of the radio frequency signal output by the radio frequency signal source (3), the spacing between the teeth of the electro-optic frequency comb can be tuned, thereby tuning the channel spacing of the coherent optical communication system.

8. A method of using the coherent optical communication system driven by the integrated electro-optic frequency comb as described in any one of claims 1-6, characterized in that, By adjusting the power and phase of the radio frequency signal loaded by the radio frequency signal distribution module (4) onto each modulator on the electro-optic frequency comb chip (2), the flatness and number of comb teeth of the electro-optic frequency comb are tuned, so that the flatness fluctuation of the electro-optic frequency comb does not exceed 10 dB, and the number of channels of the optical communication system is tuned.

9. A method of using the coherent optical communication system driven by the integrated electro-optic frequency comb as described in any one of claims 1-6, characterized in that, By adjusting the arbitrary waveform generator (6), a baseband or radio frequency signal with a corresponding preset modulation format is generated, thereby realizing the reconstruction of the modulation format and transmission rate in the optical communication system.

10. A method of using the coherent optical communication system driven by the integrated electro-optic frequency comb as described in any one of claims 1-6, characterized in that, When the continuous wave laser (1) outputs only a continuous wave light signal with a center wavelength, the electro-optic frequency comb chip (2) can generate an electro-optic frequency comb with a center wavelength. When the continuous wave laser (1) outputs multiple continuous wave optical signals with different center wavelengths at the same time, the electro-optic frequency comb chip (2) can generate multiple electro-optic frequency combs with multiple center wavelengths, thereby expanding the number of channels in the coherent optical communication system.

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