Multi-source integrated ultra-high-speed optical communication system of edge emission coherent array laser

Abstract

The invention provides an edge emission coherent array laser multi-source integrated ultra-high-speed optical communication system, and relates to the technical field of optical communication, a part of laser sources in an emission end laser source array output optical signals to carry data information, and a part of the laser sources output optical signals to generate local reference signals; optical signals bearing data information are subjected to phase or amplitude modulation through the high-speed modulator and then input into the polarization multiplexing module to perform polarization control on part of or all the optical signals, and the merging module merges all the optical signals and local reference signals and outputs the merged signals to an optical fiber link; and a receiving end wave division module receives the optical signal output by the optical fiber link and separates a local reference optical signal and a data optical signal, and a coherent detection module performs coherent detection on the data optical signal based on the local reference optical signal to obtain data information. Through the multi-channel laser source, the high-speed modulator and the self-adaptive local reference light path, Pb / s-level and even no-upper-limit data transmission capability is realized, and the system has high bandwidth, low bit error rate and high integration level.

Description

Technical Field

[0001] The present invention relates to the field of optical communication technology, and relates to a multi-source integrated ultra-high-speed optical communication system for edge-emitting coherent array lasers. Background Art

[0002] With the explosive growth of services such as artificial intelligence, cloud computing, edge computing, and high-definition video, the global data traffic shows an exponential upward trend. Traditional coherent optical communication systems usually use discrete devices to implement the functions of light sources, modulation, and detection, with low integration. In this case, the output power, line width, and stability of discrete light sources are difficult to meet the requirements of high-speed transmission. The discrete modulation and detection devices lack efficient coordination and cannot process high-speed signals in a timely manner. At rates above Tb / s, the phase, amplitude, and polarization state of the signal change extremely fast, and discrete devices are difficult to accurately track and process these changes; the low system integration results in poor compatibility between the DSP and other discrete devices, and the role of the DSP in compensating for dispersion, suppressing noise, and eliminating nonlinear effects cannot be fully exerted, leading to a decline in signal quality and an increase in the bit error rate. Therefore, traditional coherent optical communication systems are difficult to meet the future requirements of rates up to Tb / s or even Pb / s.

[0003] In recent years, the development of new materials and processes such as thin-film lithium niobate (LiNbO3) and silicon photonics platforms has made it possible to achieve high-performance and low-cost integrated coherent optical communication systems. However, the following problems still exist in the prior art: (1) The bandwidth of the modulator is limited and it is difficult to support the single-channel rate of Tb / s; (2) The low integration of the multi-channel system leads to a sharp increase in power consumption, cost, and complexity; (3) The local reference signal (LO) depends on an external light source, which limits the flexibility and scalability of the system; (4) There is a lack of a unified architecture to support the coordinated operation of multiple multiplexing methods such as polarization multiplexing, wavelength division multiplexing, and space division multiplexing.

[0004] Therefore, it is urgent to construct a coherent optical communication system with high integration, multi-dimensional multiplexing, and flexible adaptation to multiple modulation formats to meet the future communication requirements of up to 1000 Tbps or even Pb / s. Summary of the Invention

[0005] In view of the above problems, the present invention provides a multi-source integrated ultra-high-speed optical communication system for edge-emitting coherent array lasers, which realizes unlimited data transmission capacity while taking into account low bit error rate, low cost, and high reliability by introducing a high-speed interferometric modulator array, a multi-dimensional multiplexing mechanism, an adaptive local reference optical path, and a scalable receiving architecture.

[0006] To achieve the above object, the present invention provides a multi-source integrated ultra-high-speed optical communication system for an edge-emitting coherent array laser, including a transmitting end and a receiving end; The transmitting end includes a laser source array connected in sequence. The optical signals output by at least one laser source in the laser source array are used to carry data information, and the optical signals output by the remaining at least one laser source are used to generate a local reference signal. All the optical signals carrying data information are respectively input into a high-speed modulator. After the high-speed modulator performs phase or amplitude modulation on the optical signals, the signals are output to a polarization multiplexing module. The polarization multiplexing module performs polarization control on some or all of the optical signals and then outputs the signals to a combining module. The combining module combines all the input optical signals and the local reference signal into one optical signal and outputs the signal to an optical fiber link; The receiving end includes a demultiplexing module, a coherent detection module, and a digital signal processing module connected in sequence. The demultiplexing module receives the optical signal transmitted through the optical fiber link, separates the local reference optical signal and the data optical signal, and the coherent detection module performs coherent detection on the data optical signal based on the local reference optical signal to obtain data information.

[0007] As a further improvement of the present invention, the laser source array adopts an integrated coherent array laser or an independent laser array.

[0008] As a further improvement of the present invention, a phase-locked loop or an optical phase locking circuit is used to control the high-precision synchronization of each laser source in the laser source array.

[0009] As a further improvement of the present invention, the high-speed modulator is an interference type structure based on thin-film lithium niobate, silicon photonics, indium phosphide or polymer materials, including a Mach-Zehnder interferometer, a ring resonator and a directional coupler, and the bandwidth is not less than 40 GHz.

[0010] As a further improvement of the present invention, the polarization multiplexing module includes a polarization controller, a wave plate and a polarization beam splitter arranged in sequence to dynamically adjust the polarization state of the optical signal.

[0011] As a further improvement of the present invention, the laser source array is integrated with a thermoelectric modulation unit, and the thermoelectric modulation unit controls the temperature of the lasers in the laser source array to achieve fast wavelength stability.

[0012] As a further improvement of the present invention, the combining module adopts a wavelength division multiplexer or a spatial multiplexer to combine all the data optical signals and the local reference signal according to the wavelength or the spatial dimension.

[0013] As a further improvement of the present invention, the combining module is integrated with an optical amplifier, a filter and an isolator.

[0014] As a further improvement of the present invention, the coherent detection includes self-homodyne detection, heterodyne detection or co-frequency homodyne detection.

[0015] As a further improvement of the present invention, the demultiplexing module separates optical signals through a demultiplexer or an optical-electric hybrid filter.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The multi-source integrated ultra-high-speed optical communication system of the edge-emitting coherent array laser of the present invention realizes data transmission capacity at the Pb / s level or even without an upper limit through the design of a multi-channel laser source, a high-speed modulator array and an adaptive local reference optical path, and at the same time has core advantages such as high bandwidth, low bit error rate, and high integration. This system is applicable to ultra-high-speed optical communication scenarios such as data center interconnection, 6G fronthaul / midhaul, metropolitan area network, and backbone network, and has broad market prospects and application value.

[0017] The communication system of the present invention has ultra-high bandwidth. The bandwidth of a single modulator is ≥ 40 GHz, and can reach up to 100 GHz, supporting single-channel rate at the Tb / s level; combined with multi-dimensional multiplexing (WDM, SDM, PolMux) combination, it realizes the total rate at the Pb / s level; the system design supports an infinitely expandable architecture, and there is theoretically no upper limit on bandwidth.

[0018] The communication system of the present invention has extremely large capacity, supports multiple modulation formats (QPSK, QAM, DP-QAM, etc.) and multi-dimensional multiplexing, significantly improving the spectral efficiency; polarization multiplexing doubles the channel capacity, and WDM provides dozens to hundreds of channels for parallel transmission; it supports an elastic expansion mechanism and can increase the number of channels at any time according to service requirements.

[0019] The communication system of the present invention has a low bit error rate. The local reference signal and the data signal share the same source, reducing the influence of phase noise; the coherent detection technology provides high sensitivity and anti-interference ability, significantly reducing the bit error rate; DSP and AI technologies assist in demodulation, further improving the signal recovery accuracy.

[0020] The communication system of the present invention has high integration, and all modules can be implemented using integrated chips; it is particularly suitable for silicon photonics platforms or thin-film lithium niobate platforms, supporting large-scale production and deployment.

[0021] The communication system of the present invention reduces the dependence on external light sources, reduces system complexity and maintenance costs; the high-integration design reduces the number of components and manufacturing costs; it supports modular deployment, facilitating later maintenance and upgrade. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a complete structural schematic diagram of the edge-emitting coherent array laser multi-source integrated ultra-high-speed optical communication system disclosed in an embodiment of the present invention; Figure 2 Schematic diagram of the detailed structure of the transmitting end of a multi-source integrated ultra-high-speed optical communication system with an edge-emitting coherent array laser disclosed in an embodiment of the present invention; Figure 3 Schematic diagram of the detailed structure of the receiving end of a multi-source integrated ultra-high-speed optical communication system with an edge-emitting coherent array laser disclosed in an embodiment of the present invention. Specific embodiments

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] The present invention will be further described in detail below with reference to the accompanying drawings: As Figure 1 shown, a multi-source integrated ultra-high-speed optical communication system with an edge-emitting coherent array laser provided by the present invention includes a transmitting end and a receiving end; The transmitting end includes a laser source array connected in sequence. The optical signals output by at least one laser source in the laser source array are used to carry data information, and the optical signals output by the remaining at least one laser source are used to generate a local reference signal. All the optical signals carrying data information are respectively input into a high-speed modulator. The high-speed modulator modulates the optical signals in terms of phase or amplitude and then outputs them to a polarization multiplexing module. The polarization multiplexing module performs polarization control on some or all of the optical signals and then outputs them to a combining module. The combining module combines all the input optical signals and the local reference signal into one optical signal and outputs it to an optical fiber link; The receiving end includes a demultiplexing module, a coherent detection module, and a digital signal processing module connected in sequence. The demultiplexing module receives the optical signals transmitted through the optical fiber link, separates the local reference optical signal and the data optical signal, and the coherent detection module performs coherent detection on the data optical signal based on the local reference optical signal to obtain data information.

[0025] Among them, The detailed structure of the transmitting end of the present invention is as Figure 2As shown in the figure, it includes a laser source array and a high-speed interferometric modulation array connected in sequence. Among the laser sources in the laser source array, the light emitted by some laser sources serves as data channels to carry data information, and some are used to generate local reference signals. That is, multiple data signals and a local reference signal are obtained from the laser source array. After the data signals are modulated by a modulator respectively and then polarization-controlled respectively, the local reference signal is filtered / attenuated to purify the optical spectrum of the local reference signal and optimize the optical power matching. The polarization-controlled data signals and the filtered / attenuated local reference signal are aggregated and merged by a merging module into a single optical signal and output to an optical fiber link; Specifically, The laser source array in the present invention: (1) It includes at least N laser sources, where one or more are used to carry data information, and the remaining one or more are used to generate local reference signals; (2) The laser source array adopts an integrated coherent array laser or an independent laser array. The independent laser array is a light source array composed of multiple independent lasers, and the frequencies and phases of the laser sources are synchronized with each other.

[0026] (3) It supports the dynamic frequency tuning function, which is convenient for realizing flexible wavelength allocation and wavelength division multiplexing; (4) The high-precision synchronization of the laser sources in the laser source array is controlled by a phase-locked loop or an optical phase-locking circuit.

[0027] (5) The laser source array is integrated with a thermoelectric modulation unit, and the thermoelectric modulation unit controls the temperature of the lasers in the laser source array to achieve fast wavelength stabilization.

[0028] The local reference signal in the present invention: The local reference signal generated by the lasers in the laser source array or an independent laser source at the transmitting end needs to be filtered and attenuated.

[0029] The high-speed modulator in the present invention: (1) A high-speed interferometric modulator array composed of one or more high-speed interferometric modulators, corresponding to one or more optical signals used to carry data information respectively, receiving the optical signals output by the laser source, and performing phase or amplitude modulation on the optical signals; (2) The high-speed modulator is an interferometric structure based on thin-film lithium niobate, silicon photonics, indium phosphide or polymer materials. Preferably, its bandwidth is not less than 40 GHz, and some high-end models can reach more than 100 GHz; the interferometric structure can select Mach-Zehnder interferometers, ring resonators, directional couplers, etc.; (3) It supports multiple modulation formats, including QPSK, QAM, DP-QPSK, DP-16QAM, DP-64QAM, etc.; (4) The partial high-speed modulator is built-in with a digital predistortion module for compensating non-linear effects.

[0030] The polarization multiplexing module in the present invention: (1) The polarization multiplexing module is a flexible and optional module; (2) It includes a polarization controller, a wave plate, and a polarization beam splitter arranged in sequence to dynamically adjust the polarization state of the optical signal; (3) It performs polarization control on some or all of the modulated optical signals to achieve dual-polarization modulation, so as to increase the channel capacity.

[0031] (4) It supports the combined use of polarization multiplexing and multi-dimensional multiplexing technologies such as wavelength division multiplexing and spatial multiplexing.

[0032] The combining module in the present invention: (1) It uses a wavelength division multiplexer or a spatial multiplexer to combine all data optical signals and local reference optical signals according to the wavelength or spatial dimension; (2) It combines the modulated multiple data optical signals and the local reference optical signal into one optical signal and outputs it to the optical fiber link; (3) It is integrated with functional units such as an optical amplifier, a filter, and an isolator to improve signal integrity; (4) It supports an elastic multiplexing mechanism and can dynamically add new channels without affecting the operation of the existing system.

[0033] Further, The detailed structure of the receiving end in the present invention is as Figure 3 shown: A fiber input interface is provided at the front end of the demultiplexing module, which is connected to the fiber link from the fiber output interface of the combining module. The demultiplexing module separates an optical signal input from the fiber link into multiple data optical signals and a local reference optical signal, and inputs the multiple data optical signals into a coherent detection module respectively. The coherent detection module performs coherent detection on each data optical signal based on the local reference optical signal and outputs I / Q electrical signals. The I / Q electrical signals are processed by a data signal processing module (DSP) such as equalization, adjustment, error correction, etc., to obtain multiple data and summarize them. Then, the AI-assisted demodulation module restores the multiple data and outputs the data.

[0034] Specifically, The receiving end in the present invention: (1) It includes a demultiplexing module and a coherent detection module for separating data optical signals from local reference optical signals and performing coherent detection on the data optical signals based on the local reference optical signal; (3) The demultiplexing module separates the optical signal through a demultiplexer or an optoelectronic hybrid filter. Further, as Figure 3 shown, it is separated into data optical signals and local reference optical signals of multiple channels; (2) The coherent detection module includes a 90° mixer and a balanced detector. As shown in Figure 3 the figure, coherent detection is performed on each data channel to output I / Q electrical signals. Coherent detection includes self-homodyne detection, heterodyne detection, or homodyne zero-difference detection, etc.; (4) Support digital signal processing (DSP) algorithms for operations such as demodulation, equalization, and error correction; (5) An AI-assisted demodulation module can be optionally configured to improve the recovery ability under complex channels.

[0035] The local reference optical signal in the present invention: A local reference optical signal extraction unit is provided, which can be extracted by self-homodyne and the extraction path in the data channel is marked.

[0036] The optical fiber link in the present invention: As an optical signal transmission medium, it connects the transmitter and the receiver. Specifically, a fiber optic input interface is provided at the front end of the demultiplexing module at the receiver to receive the multiplexed optical signal from the transmitter. Embodiment 1:

[0037] The transmitter is provided with a laser source array including 64 laser channels and 8 local reference optical channels. Each laser channel is connected to a thin-film lithium niobate MZI modulator, and 32 of the channels achieve dual-polarization modulation through a polarization multiplexing module. All modulated signals are combined with the local reference optical signal through WDM and then sent to the receiver.

[0038] The receiver uses a coherent detector for self-homodyne detection and is supplemented by DSP for signal recovery, achieving a total transmission rate of 1024 Tbps (1 Pbps). Embodiment 2:

[0039] The transmitter is provided with a laser source array composed of multiple independent lasers, and frequency synchronization is achieved through a phase-locked circuit. The high-speed modulator is a Mach-Zehnder structure on a silicon photonics platform, supporting a modulation bandwidth of up to 100 GHz. The local reference signal is obtained by splitting a part of the optical power from one of the data channels and then filtering and attenuating it. The receiver uses heterodyne detection to complete signal demodulation and improves the bit error rate performance through an AI demodulation module, achieving an elastic expansion ability without an upper limit.

[0040] Advantages of the present invention: The multi-source integrated ultra-high-speed optical communication system of the edge-emitting coherent array laser of the present invention realizes data transmission capabilities at the Pb / s level and even without an upper limit through the design of multi-channel laser sources, high-speed modulator arrays, and adaptive local reference optical paths. At the same time, it has core advantages such as high bandwidth, low bit error rate, and high integration. This system is applicable to ultra-high-speed optical communication scenarios such as data center interconnection, 6G fronthaul / midhaul, metropolitan area networks, and backbone networks, and has broad market prospects and application value.

[0041] The communication system of the present invention has ultra-high bandwidth. The bandwidth of a single modulator ≥ 40 GHz, up to 100 GHz, supporting single-channel rates at the Tb / s level; combined with multi-dimensional multiplexing (WDM, SDM, PolMux) combinations, achieving a total rate at the Pb / s level; the system design supports an infinitely expandable architecture, and there is theoretically no bandwidth upper limit.

[0042] The communication system of the present invention has an extremely large capacity, supports various modulation formats (QPSK, QAM, DP-QAM, etc.) and multi-dimensional multiplexing, significantly improving the spectral efficiency; polarization multiplexing doubles the channel capacity, and WDM provides dozens to hundreds of channels for parallel transmission; it supports an elastic expansion mechanism and can increase the number of channels at any time according to service requirements.

[0043] The communication system of the present invention has a low bit error rate. The local reference signal and the data signal share the same source, reducing the influence of phase noise; coherent detection technology provides high sensitivity and anti-interference ability, significantly reducing the bit error rate; DSP and AI technologies assist in demodulation, further improving the signal recovery accuracy.

[0044] The communication system of the present invention has high integration, and all modules can be implemented using integrated chips; it is particularly suitable for silicon photonics platforms or thin-film lithium niobate platforms, supporting large-scale production and deployment.

[0045] The communication system of the present invention reduces the dependence on external light sources, reduces system complexity and maintenance costs; the high-integration design reduces the number of components and reduces manufacturing costs; it supports modular deployment, facilitating later maintenance and upgrade.

[0046] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. Edge-emitting coherent array laser multi-source integrated ultra-high-speed optical communication system, characterized in that: It includes a transmitting end and a receiving end; The transmitting end includes a laser source array connected in sequence. The optical signals output by at least one laser source in the laser source array are used to carry data information, and the optical signals output by the remaining at least one laser source are used to generate a local reference signal. All the optical signals carrying data information are respectively input into a high-speed modulator. The high-speed modulator modulates the optical signals in terms of phase or amplitude and then outputs them to a polarization multiplexing module. The polarization multiplexing module performs polarization control on some or all of the optical signals and then outputs them to a combining module. The combining module combines all the input optical signals and the local reference signal into one optical signal and outputs it to an optical fiber link; The receiving end includes a demultiplexing module, a coherent detection module, and a digital signal processing module connected in sequence. The demultiplexing module receives the optical signal transmitted through the optical fiber link and separates the local reference optical signal and the data optical signal. The coherent detection module performs coherent detection on the data optical signal based on the local reference optical signal to obtain data information.

2. The edge-emitting coherent array laser multi-source integrated ultra-high-speed optical communication system according to claim 1, wherein The laser source array uses an integrated coherent array laser or an independent laser array.

3. The edge-emitting coherent array laser multi-source integrated ultra-high-speed optical communication system according to claim 1, characterized in that: The high-precision synchronization of each laser source in the laser source array is controlled by a phase-locked loop or an optical phase-locking circuit.

4. The edge-emitting coherent array laser multi-source integrated ultra-high-speed optical communication system according to claim 1, characterized in that: The high-speed modulator is an interference type structure based on thin-film lithium niobate, silicon photonics, indium phosphide, or polymer materials, including a Mach-Zehnder interferometer, a ring resonator, and a directional coupler, with a bandwidth not less than 40 GHz.

5. The edge-emitting coherent array laser multi-source integrated ultra-high-speed optical communication system according to claim 1, characterized in that: The polarization multiplexing module includes a polarization controller, a wave plate, and a polarization beam splitter arranged in sequence to dynamically adjust the polarization state of the optical signal.

6. The edge-emitting coherent array laser multi-source integrated ultra-high-speed optical communication system according to claim 1, characterized in that: The laser source array is integrated with a thermoelectric modulation unit, and the thermoelectric modulation unit controls the temperature of the lasers in the laser source array to achieve fast wavelength stability.

7. The edge-emitting coherent array laser multi-source integrated ultra-high-speed optical communication system according to claim 1, characterized in that: The combining module uses a wavelength division multiplexer or a spatial multiplexer to combine all the data optical signals and the local reference signal according to the wavelength or spatial dimension.

8. The edge-emitting coherent array laser multi-source integrated ultra-high-speed optical communication system according to claim 1, characterized in that: The combining module is integrated with an optical amplifier, a filter, and an isolator.

9. The edge-emitting coherent array laser multi-source integrated ultra-high-speed optical communication system according to claim 1, characterized in that: The coherent detection includes self-homodyne detection, heterodyne detection, or homodyne detection with the same frequency.

10. The edge-emitting coherent array laser multi-source integrated ultra-high-speed optical communication system according to claim 1, characterized in that: The demultiplexing module separates the optical signal through a demultiplexing multiplexer or an optoelectronic hybrid filter.

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