Optical frequency comb self-starting device and method

Abstract

The invention provides an optical frequency comb self-starting device and method. A laser generates a pump light signal; the photon chip outputs an optical frequency comb signal and transmits a pump light signal, the photon chip comprises an optical microresonator and a coupling waveguide, and the optical microresonator and the coupling waveguide are both provided with tuning electrodes; the acquisition system monitors a pump light signal and an optical frequency comb signal in real time; and the control system automatically identifies a mode locking signal according to a monitoring result, judges whether the optical frequency comb reaches a mode locking state or not, adjusts the pumping current and the tuning electrode voltage according to the mode locking signal, and generates a mode locking state optical frequency comb signal of a target wavelength. According to the invention, the mode of the laser and the mode of the micro-resonator can be automatically interlocked, the mode-locked state optical frequency comb can be generated without manual intervention, and the mode-locked state optical frequency comb signal with continuously tunable wavelength can be automatically and controllably generated through the coordinated adjustment of multiple parameters such as tuning electrode voltage and pumping current and the automatic identification of the mode-locked state.

Description

Technical Field

[0001] The present invention relates to the field of laser technology, and in particular to an optical frequency comb self-starting device and method. Background Art

[0002] Optical frequency combs appear as equally spaced pulse signals in the time domain and equally spaced frequency components in the frequency domain. They are widely used in precision measurement, optical communications, and optical computing. Optical frequency combs based on the Kerr effect of microresonators have advantages such as low power consumption and easy integration, but existing technologies have the following drawbacks: Traditional optical frequency combs rely on fixed resonator modes and cannot dynamically adapt to the multi-wavelength requirements of scenarios such as optical communications and precision measurement, resulting in system redundancy and increased costs. Existing solutions require manual adjustment of pump light and thermal balance parameters, which has low experimental efficiency and is difficult to deploy outside the laboratory. Existing devices rely on discrete components (such as amplifiers and polarization modulators), resulting in bulky size. Traditional methods have difficulty in automatically identifying and switching between different locking modes and require real-time monitoring by professionals.

[0003] Therefore, there is an urgent need for an optical frequency comb device that can achieve fully automatic startup and continuous wavelength tuning. Summary of the Invention

[0004] The present invention provides a self-starting device and method for an optical frequency comb, which is used to solve the defects in the prior art that it is difficult to automatically identify and switch between different locking modes, and manual parameter adjustment is required, resulting in low experimental efficiency and difficulty in deployment outside the laboratory. The device and method can realize the complete self-starting of the optical frequency comb and the controllable generation of different locking modes.

[0005] The present invention provides an optical frequency comb self-starting device, comprising a laser, a photonic chip, a control system and an acquisition system; The laser is used to generate a pump light signal; The photonic chip is used to output an optical frequency comb signal and transmit a pump light signal. The photonic chip includes an integrated optical microresonator and a coupled waveguide. The optical microresonator is provided with a microresonator tuning electrode, and the coupled waveguide is provided with a waveguide phase tuning electrode. The acquisition system is used to monitor the pump light signal and the optical frequency comb signal in real time; The control system is connected to the laser, the microresonator tuning electrode, the waveguide phase tuning electrode, and the acquisition system, respectively. The control system is used to automatically identify a mode-locked signal based on monitoring results of the pump light signal and the optical frequency comb signal fed back by the acquisition system, and adjust the pump current of the laser, the control voltage of the microresonator tuning electrode, and the control voltage of the waveguide phase tuning electrode based on the mode-locked signal identification result, so that the photonic chip generates a mode-locked optical frequency comb signal of a target wavelength.

[0006] According to the optical frequency comb self-starting device provided by the present invention, the device further includes a wavelength division multiplexer and a beam splitter; The laser inputs the pump light signal into the photonic chip coupling waveguide; the pump light signal is coupled to the optical microresonator through the evanescent field effect, and the backscattered light generated by the optical microresonator is coupled to the coupling waveguide and transmitted back to the laser cavity, thereby generating a self-injection locking effect; The wavelength division multiplexer is used to divide the output signal of the received photonic chip into a pump light signal and an optical frequency comb signal, and output the pump light signal as the first monitoring signal to the acquisition system; The beam splitter is used to receive the optical frequency comb signal, split the optical frequency comb signal into an optical frequency comb output signal and a second monitoring signal according to a preset ratio, and output the second monitoring signal to the acquisition system.

[0007] According to the optical frequency comb self-starting device provided by the present invention, the control system includes a tunable constant current source, a multi-channel electrode driving module, a temperature control module and a main control chip; The tunable constant current source is used to provide an adjustable laser pump current for the laser; The multi-channel electrode driving module includes a micro-resonator tuning electrode driving module and a waveguide phase tuning electrode driving module, wherein the micro-resonator tuning electrode driving module is used to tune the resonant mode of the optical micro-resonator, and the waveguide phase tuning electrode driving module is used to adjust the optical phase of the coupled waveguide; The temperature control module is used to control the operating temperature of the laser; The main control chip integrates a continuously tunable optical frequency comb self-starting algorithm, which is used to perform mode-locking signal judgment based on the first monitoring signal and the second monitoring signal received in real time, and automatically adjust the pump current, multi-channel electrode voltage driving module and temperature control module according to the mode-locking signal judgment result to generate a mode-locked state frequency comb signal of the target wavelength.

[0008] According to the optical frequency comb self-starting device provided by the present invention, the optical microresonator includes a first microresonator and a second microresonator coupled to each other, and the first microresonator and the second microresonator are both provided with a first microresonator tuning electrode. By jointly adjusting the control voltages of the two first microresonator tuning electrodes, the first microresonator and the second microresonator are coupled to achieve pump enhancement.

[0009] According to the optical frequency comb self-starting device provided by the present invention, the optical microresonator includes a third microresonator and a fourth microresonator that are coupled to each other. The fourth microresonator and the third microresonator are both provided with a second microresonator tuning electrode. By adjusting the control voltages of the two second microresonator tuning electrodes in a linked manner, mode splitting is selectively applied to the pump mode of the third microresonator. When the resonant mode of the third microresonator resonates with the pump laser, the pump laser is simultaneously detuned in the far-infrared relative to the original position of the pump mode of the third microresonator.

[0010] The present invention further provides an optical frequency comb self-starting method, which is implemented by any of the above optical frequency comb self-starting devices, and the method comprises: The interlocking relationship between the laser and the optical microresonator is established through self-injection locking, and the optical frequency comb signal and the transmission pump light signal are output through the photonic chip; Based on the optical frequency comb signal and the pump light signal, the pump current of the laser, the control voltage of the microresonator tuning electrode, and the control voltage of the waveguide phase tuning electrode are adjusted in a coordinated manner so that the photonic chip generates a mode-locked optical frequency comb signal of a target wavelength; In the process of generating a mode-locked optical frequency comb signal of a target wavelength, determining whether a mode-locked signal exists based on a monitoring result of the optical frequency comb signal, and if it is determined that the mode-locked signal exists, determining the power corresponding to the mode-locked frequency comb signals of different wavelengths; Based on the power and mode-locked signal judgment results corresponding to the target wavelength mode-locked state frequency comb signal, the control voltage of the microresonator tuning electrode and the control voltage of the waveguide phase tuning electrode are adjusted so that the photonic chip automatically generates and outputs the target wavelength mode-locked state optical frequency comb signal.

[0011] According to the optical frequency comb self-starting method provided by the present invention, the interlocking relationship between the laser and the optical microresonator is established by self-injection locking, specifically comprising: Outputting pump light through a laser, the pump light is introduced into the coupling waveguide of the photonic chip and coupled to the optical microresonator through the evanescent field effect; Part of the pump light is backscattered by the roughness of the optical microresonator surface and returns to the laser cavity along the coupling waveguide, generating a self-injection locking effect; When the initial detuning between the laser output mode and the optical microresonator is within a preset range and the backscattered light meets the feedback phase condition, the optical frequency comb signal output is achieved.

[0012] According to the optical frequency comb self-starting method provided by the present invention, based on the pump light signal and the optical frequency comb signal, the pump current of the laser, the control voltage of the microresonator tuning electrode, and the control voltage of the waveguide phase tuning electrode are linked and adjusted to generate a mode-locked optical frequency comb signal of a target wavelength, specifically comprising: Adjust the laser pump current to control the laser wavelength to the target wavelength, and scan the microresonator tuning electrode control voltage , determining whether a microresonator resonant mode exists according to the pump light signal; Adjust the waveguide phase tuning electrode control voltage , determining whether a mode-locked state exists according to the optical frequency comb signal; The power of different mode-locked states is marked, and the control voltage of the resonator tuning electrode is adjusted based on the target mode-locked state power to generate a target mode-locked state optical frequency comb signal.

[0013] According to the optical frequency comb self-starting method provided by the present invention, after completing the generation of the target wavelength mode-locked optical frequency comb signal, the method further includes finely adjusting the output wavelength, specifically comprising: According to the target wavelength, adjusting the control voltage of the microresonator tuning electrode, the pump current of the laser, and the control voltage of the waveguide phase tuning electrode; During the adjustment process, whether the mode-locked state is maintained is determined according to the optical frequency comb signal.

[0014] According to the optical frequency comb self-starting method provided by the present invention, judging whether a mode-locked signal exists based on the monitoring result of the optical frequency comb signal specifically includes: Obtaining a voltage signal array corresponding to the optical frequency comb signal to be determined; Determine the global maximum value in the voltage signal array, The global maximum value is used as the starting point of the effective voltage signal to be analyzed, the voltage signal array is segmented by the first-order difference of the effective data group, and each segment of data in the voltage signal array is marked as being in a mode-locked state by the continuous interval length, data segment slope, and data segment amplitude of each segment.

[0015] According to the optical frequency comb self-starting method provided by the present invention, based on the power corresponding to the frequency comb signal in the mode-locked state of the target wavelength and the mode-locked signal judgment result, the control voltage of the microresonator tuning electrode and the control voltage of the waveguide phase tuning electrode are adjusted to complete the automatic generation of the optical frequency comb signal in the mode-locked state of the target wavelength, including: Based on the power and mode-locked signal judgment results corresponding to the frequency comb signal in the target wavelength mode-locked state, the control voltage of the microresonator tuning electrode and the control voltage of the waveguide phase tuning electrode are adjusted so that the power and peak-to-peak value of the optical frequency comb signal are within the threshold range, thereby completing the automatic generation of the optical frequency comb signal in the target wavelength mode-locked state.

[0016] The present invention provides an optical frequency comb self-starting device and method, comprising a laser, a photonic chip, a control system, and an acquisition system. The laser is used to generate a pump light signal. The photonic chip is used to output an optical frequency comb signal and transmit the pump light signal. The photonic chip includes an integrated optical microresonator and a coupled waveguide, wherein the optical microresonator is provided with a microresonator tuning electrode, and the coupled waveguide is provided with a waveguide phase tuning electrode. The acquisition system is used to monitor the pump light signal and the optical frequency comb signal in real time. The control system is connected to the laser, the microresonator tuning electrode, the waveguide phase tuning electrode, and the acquisition system, respectively. The control system is used to automatically identify a mode-locked signal based on monitoring results of the pump light signal and the optical frequency comb signal fed back by the acquisition system, and to adjust the pump current of the laser, the control voltage of the microresonator tuning electrode, and the control voltage of the waveguide phase tuning electrode based on the mode-locked signal identification results, so that the photonic chip generates a mode-locked optical frequency comb signal of a target wavelength. The present invention uses self-injection locking technology to automatically interlock the laser and microresonator modes, generating a mode-locked optical frequency comb without human intervention. By coordinating the adjustment of multiple parameters such as the microresonator electrode voltage and the laser pump current, continuous tuning of the optical frequency comb wavelength is achieved. The mode-locked state is automatically identified through the mode-locking signal judgment logic, achieving controllable generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 It is a schematic structural diagram of the optical frequency comb self-starting device provided by the present invention.

[0019] Figure 2 This is a schematic diagram of the coupling between the laser and the single resonator structure photonic chip provided by the present invention.

[0020] Figure 3 This is a schematic diagram of the single optical microresonator structure of the annular on-chip microresonator structure provided by the present invention.

[0021] Figure 4 This is a schematic diagram of the single optical microresonator structure of the vortex linear on-chip microresonator structure provided by the present invention.

[0022] Figure 5 This is a schematic diagram of the dual optical microresonator structure provided by the present invention, in which a first microresonator and a second microresonator are resonantly coupled.

[0023] Figure 6 It is a schematic diagram of the structure of a dual optical microresonator with resonant coupling of a third microresonator and a fourth microresonator provided by the present invention.

[0024] Figure 7 A schematic flow chart of the optical frequency comb self-starting method provided by the present invention.

[0025] Figure 8 The present invention provides continuously tunable self-starting optical frequency comb control logic.

[0026] Figure 9 The present invention provides mode-locking signal judgment logic.

[0027] Figure 10 Schematic diagram of the optical frequency comb mode-locking signal provided by the present invention.

[0028] Figure 11 The present invention provides optical spectra corresponding to signals of different mode-locking states.

[0029] Figure 12 A schematic diagram of a flow chart for controllably generating a locking state provided by the present invention. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0031] In practical applications, optical frequency combs appear as equally spaced pulses in the time domain and as a series of equally spaced frequency components with well-defined phase relationships in the frequency domain. They have found widespread application in cutting-edge research fields such as precision measurement, optical computing, and fiber-optic communications. In recent years, optical frequency combs generated based on the Kerr effect have become feasible at the chip level, reducing the power consumption required for comb generation and facilitating their large-scale, efficient production. Optical frequency combs offer advantages such as low power consumption, high conversion efficiency, and ease of integration, making them highly valuable for industrial applications. By balancing gain and loss, dispersion, and nonlinearities within a microresonator, a mode-locked optical frequency comb can be excited. In the frequency domain, a mode-locked optical frequency comb exhibits equally spaced, phase-coherent, and discrete spectral lines with a fixed envelope shape, maintaining a low-noise, flat output power curve, and periodic optical pulses in the time domain. The conditions for generating a mode-locked optical frequency comb are primarily that the pump power exceeds the parametric oscillation threshold and that the laser pump mode is red-detuned (i.e., shifted toward longer wavelengths) relative to the resonant mode of the microresonator. The larger the detuning, the wider the spectrum of the generated optical frequency comb, but the required pump power also increases significantly. However, the generation of optical frequency combs in microresonators often requires complex control procedures, especially for the control of thermal effects within the resonator. Currently, various methods for generating optical frequency combs have been developed, including rapid frequency tuning, assisted photothermal balance, and self-injection locking.

[0032] Traditional frequency tuning and auxiliary photothermal balancing methods generate mode-locked optical frequency combs by balancing the thermal effects within the resonator. However, there is no locking relationship between the resonator mode and the laser mode, making it impossible to achieve continuous tunability of the optical frequency comb wavelength in principle. Untunable optical frequency comb signals are difficult to directly integrate into optical communications, optical sensing, and optical computing systems, making optical frequency comb systems difficult to implement in engineering applications. Furthermore, traditional frequency tuning and auxiliary photothermal balancing methods require large and complex mode-locked optical frequency comb generation and feedback systems, making them difficult to deploy outside the laboratory. Furthermore, they require the operator to monitor the real-time spectrum or the power within the resonator to manually control the state of the pump light or auxiliary light, resulting in low experimental efficiency and poor repeatability.

[0033] Self-injection locking (SIL) technology can create a start-key optical frequency comb, but its principle is complex and requires a high level of operator expertise. A start-key optical frequency comb device without a self-starting design is impractical. Furthermore, existing start-key optical frequency comb devices still lack the ability to tune wavelengths.

[0034] At the same time, the pump power is in a square relationship with the spectral width of the optical frequency comb. Since the output power of the laser is limited, it is necessary to achieve pump enhancement through a coupling structure to increase the bandwidth of the optical frequency comb.

[0035] CN117913637A proposes a monostable single-soliton generation system and method. By simply adjusting the pump and microresonator detuning in one direction, optical frequency comb signals can be directly obtained. However, this invention still relies on an experimental platform to obtain optical frequency comb signals. The required light source, polarization controller, optical microresonator spectrometer, and oscilloscope are not portable and integrated, making them difficult to deploy outside the laboratory. Furthermore, this method of obtaining optical frequency comb signals still requires operator expertise and cannot be fully automated without manual intervention.

[0036] CN118380838A discloses a fully integrated photogenerated microwave device, in which a continuous pump laser is coupled to a microresonator module and dark pulses or bright optical frequency comb signals are generated through self-injection locking and nonlinear effects. This solution does not require an electronic feedback locking system and has small size and low power consumption. However, the obtained optical frequency comb signal lacks modulation freedom and the wavelength is not tunable. This disadvantage limits the application of optical frequency comb signals in optical communications, optical sensing, and precision measurement.

[0037] CN119148442A proposes an intelligent adaptive control and self-feedback stabilization system for a microresonator soliton frequency comb. This system utilizes an auxiliary photothermal tuning scheme, combined with an FPGA chip to monitor and control the parameters of each system component. This system achieves lumped excitation, parallel control, and collaborative feedback for the on-chip soliton frequency comb generation system. However, the auxiliary photothermal balancing method generates solitons by balancing the thermal effects within the cavity. There is no locking relationship between the cavity mode and the laser, resulting in a very short mode-locked signal length and a non-continuous wavelength tunability.

[0038] CN119575729A is an optical frequency comb generation device and method based on a lithium niobate thin film waveguide and a double microring in series, which effectively improves the efficiency of the optical frequency comb. However, it requires complex pump light and auxiliary light and coordinated modulation of the back-end device amplifier and polarization modulator to achieve power compensation, which increases the structural complexity. The difficulty in integration limits the possibility of its engineering application, and the auxiliary light-thermal balance scheme is difficult to achieve continuous tunable wavelength in principle.

[0039] To address these issues, there is an urgent need for a device that can achieve complete self-startup of the optical frequency comb and controllable generation of different locking states, quickly obtain optical frequency comb signals based on the device, improve the usability and ergonomics of the optical frequency comb, and achieve continuous tunability of the wavelength of the generated optical frequency comb signal, thereby reducing the hardware complexity and cost of laboratory or industrial systems, realizing portable packaging of the optical frequency comb system, enhancing its long-term stability, and enabling rapid deployment in environments outside the laboratory.

[0040] In view of this, the present invention provides an optical frequency comb self-starting device and method to overcome the above-mentioned defects of the prior art.

[0041] The present invention will be described in detail below with reference to specific embodiments.

[0042] In some specific embodiments of the present invention, Figure 1 As shown, this solution provides an optical frequency comb self-starting device, including a laser 11, a photonic chip 12, an acquisition system 13 and a control system 14. The laser 11 is used to generate a pump light signal; The photonic chip 12 is used to output an optical frequency comb signal and transmit a pump light signal. The photonic chip includes an integrated optical microresonator and a coupled waveguide. The optical microresonator is provided with a microresonator tuning electrode, and the coupled waveguide is provided with a waveguide phase tuning electrode. The acquisition system 13 is used to monitor the pump light signal and the optical frequency comb signal in real time; The control system 14 is connected to the laser 11, the microresonator tuning electrode, the waveguide phase tuning electrode and the acquisition system respectively. The control system 14 is used to automatically identify the mode-locked signal based on the monitoring results of the pump light signal and the optical frequency comb signal fed back by the acquisition system, and adjust the pump current of the laser, the control voltage of the microresonator tuning electrode and the control voltage of the waveguide phase tuning electrode according to the mode-locked signal identification result, so that the photonic chip generates a mode-locked optical frequency comb signal of the target wavelength.

[0043] It should be noted that existing optical frequency comb generation schemes rely on fixed resonant modes and cannot dynamically adjust the wavelength. They can only be achieved through real-time manual monitoring of the spectrum or power and manual adjustment of pump light parameters. This results in low experimental efficiency and poor repeatability, making it difficult to deploy outside the laboratory. In addition, existing schemes cannot automatically identify or switch the locked mode state, and cannot meet the practical application of optical frequency combs in optical communications, precision measurement and other fields.

[0044] Therefore, the control system of the present invention is respectively connected to the laser, the microresonator tuning electrode, and the waveguide phase tuning electrode. Based on the monitoring results of the pump light signal and the optical frequency comb signal, the control system automatically identifies the mode-locking signal. Based on the mode-locking signal identification result, the control system realizes continuous wavelength tuning through parameter collaborative tuning, automatically generates the mode-locking state, and eliminates manual intervention.

[0045] In some possible embodiments of the present invention, Figure 1 As shown, the optical frequency comb self-starting device further includes a wavelength division multiplexer 15 and a beam splitter 16; The laser 11 inputs the pump light signal into the coupling waveguide of the photonic chip; the pump light signal is coupled to the optical microresonator through the evanescent field effect, and the backscattered light generated by the optical microresonator is coupled to the coupling waveguide and transmitted back to the laser cavity, generating a self-injection locking effect; The wavelength division multiplexer 15 is used to divide the output signal of the received photonic chip into a pump light signal and an optical frequency comb signal, and output the pump light signal as the first monitoring signal to the acquisition system; The beam splitter 16 is used to receive the optical frequency comb signal, split the optical frequency comb signal into an optical frequency comb output signal and a second monitoring signal according to a preset ratio, and output the second monitoring signal to the acquisition system.

[0046] In a possible embodiment, Figure 1 As shown, the optical frequency comb self-starting device also includes a first photodetector 17 and a second photodetector 18, the input end of the first photodetector 17 is connected to the wavelength division multiplexer 15, the input end of the second photodetector 18 is connected to the beam splitter 16, and the output end of the first photodetector 17 and the output end of the second photodetector 18 are both connected to the acquisition system 13, for converting the first monitoring signal and the second monitoring signal into voltage signals and outputting them to the acquisition system 13.

[0047] Specifically, this embodiment provides an implementation of an optical frequency comb self-starting device, which generates an optical frequency comb through a self-injection locking method, and generates a monitoring signal of the pump light through the combined action of a wavelength division multiplexer and a beam splitter, such as Figure 1 The first monitoring signal in , and the monitoring signal of the generated mode-locked optical frequency comb, such as Figure 1 The second monitoring signal in.

[0048] In a possible embodiment, the input end of the isolator may be coupled to the output end of the optical microresonator to receive the pump light signal coupled out by the optical microresonator and block the reversely transmitted light.

[0049] In a possible embodiment, mode spot conversion is achieved through microlenses to optimize coupling efficiency and increase the on-chip laser power coupled to the photonic chip.

[0050] In a possible embodiment, the microlens serves as a spot converter, and its core purpose is to optimize the coupling efficiency and increase the on-chip laser power coupled to the photonic chip. The coupling efficiency can be optimized by optimizing the laser output spot parameters, designing the photonic chip end face coupling structure, and polishing the photonic chip end face.

[0051] In some possible implementations of the present invention, the laser uses a distributed feedback semiconductor laser, integrates a periodic grating structure in the active region, and utilizes Bragg reflection to selectively feedback a specific wavelength and achieve output.

[0052] Specifically, an embodiment of the present invention provides an implementation of a laser, which is a distributed feedback semiconductor laser. A periodic grating structure (Bragg grating) is integrated in the active region, and Bragg reflection is used to selectively feedback a specific wavelength and achieve output.

[0053] In some possible embodiments of the present invention, the photonic chip uses a silicon nitride material platform, and an optical microresonator and a coupling waveguide are etched on the silicon nitride material platform. Metal electrodes are attached to the waveguide section from the waveguide input port to the coupling point and to the optical microresonator through a metal lift-off process.

[0054] Specifically, the embodiment of the present invention provides an implementation method of a photonic chip, which uses a silicon nitride material platform and silicon nitride or other highly nonlinear materials to improve the quality factor (Q ≥ 10 6 ), enhancing the efficiency of four-wave mixing. The silicon nitride material platform is engraved with optical microresonators and their coupling structures with waveguides, such as Figure 2 As shown, heaters are attached to the waveguide section from the waveguide input port to the coupling point and the microresonator through a metal lift-off process to tune the microresonator cavity length and the light transmission phase of the waveguide section.

[0055] It is worth noting that the cavity membrane tuning structure and the waveguide phase tuning structure are not limited to heaters, and devices or components that can be modulated based on the electro-optical effect of the material to achieve tuning functions are applicable to this embodiment.

[0056] Furthermore, the embodiments of the present invention are described using a silicon nitride material platform as an example. The apparatus and method of the present invention are equally applicable to other photonic chip material platforms, and therefore will not be further elaborated here. The embodiments of the present invention are described using metal electrodes as an example. Different electrode materials only affect tuning efficiency and energy consumption ratio. The self-starting logic and continuously tunable logic of the mode-locked optical frequency comb do not require substantial optimization. Therefore, the apparatus and method of the present invention are equally applicable to other electrode materials and are not specifically limited in the present invention.

[0057] In a possible embodiment, the input end of the isolator is coupled to the output end of the photonic chip to ensure unidirectional transmission of light coupled from the output end of the photonic chip and to isolate the backscattered light of the back-end device from being transmitted back to the photonic chip.

[0058] In a possible embodiment, the wavelength division multiplexing input end is coupled to the isolator output end to split the optical signal into two signals: pump light and mode-locked optical frequency comb. The pump light is input into the acquisition system as the monitoring signal 1, and the mode-locked optical frequency comb signal is transmitted backward.

[0059] In a possible embodiment, the beam splitter splits the mode-locked optical frequency comb signal into an output signal and a monitoring signal 2 in a ratio of 99:1.

[0060] In a possible embodiment, the beam splitter may be selected with a ratio of 90:10 or other ratios in addition to 99:1. The specific ratio may be pre-set according to different task requirements.

[0061] In some possible implementations of the present invention, the acquisition system includes two acquisition modules, which are respectively used to receive the first monitoring signal and the second monitoring signal.

[0062] Specifically, an embodiment of the present invention provides an implementation of an acquisition system, which includes two photodiodes, corresponding transimpedance amplifier circuits and an acquisition module, respectively monitoring a pump light signal and an optical frequency comb monitoring light signal.

[0063] In a possible embodiment, the acquisition system is encapsulated in the optical frequency comb device and can be composed of a photodetector and an acquisition card. However, for the method proposed in the present invention, a bench-top oscilloscope and a data acquisition card can also be used as the acquisition system. Compared with integrated photodetectors and acquisition cards, these alternative solutions are large in size and high in cost, which is not conducive to the portable integration and rapid deployment of the locked optical frequency comb system. However, the corresponding technical indicators such as sampling accuracy, sampling bandwidth, and sampling depth are better, and can be selected on the experimental platform as a suboptimal solution.

[0064] In some possible implementations of the present invention, the control system includes a tunable constant current source, a multi-channel electrode driving module, a temperature control module and a main control chip; The tunable constant current source is used to provide an adjustable laser pump current for the laser; The multi-channel electrode driving module includes a micro-resonator tuning electrode driving module and a waveguide phase tuning electrode driving module, wherein the micro-resonator tuning electrode driving module is used to tune the resonant mode of the optical micro-resonator, and the waveguide phase tuning electrode driving module is used to adjust the optical phase of the coupled waveguide; The temperature control module is used to control the operating temperature of the laser; The main control chip integrates a continuously tunable optical frequency comb self-starting algorithm, which is used to perform mode-locking signal judgment based on the first monitoring signal and the second monitoring signal received in real time, and automatically adjust the pump current, multi-channel electrode voltage driving module and temperature control module according to the mode-locking signal judgment result to generate a mode-locked state frequency comb signal of the target wavelength.

[0065] Specifically, an embodiment of the present invention provides an implementation method of a control system, which includes a tunable low-noise laser pump constant current source, high-precision temperature control, and multi-channel tunable low-noise electrode drive, such as a single-chip microcomputer that can be used as a main control chip to perform calculations, control, and resource scheduling.

[0066] In a possible embodiment, the control system is integrated on a circuit board, with a single-chip microcomputer as the main controller. According to the architecture and method proposed in the present invention, a computer, FPGA or other control system can also be used as the host computer to implement calculations and control.

[0067] In some possible implementations of the present invention, the optical microresonator includes a single optical microresonator or a dual optical microresonator resonant coupling structure.

[0068] Specifically, an embodiment of the present invention provides an implementation of a photonic chip, which uses a single optical microresonator or a dual optical microresonator resonant coupling structure to realize the function of an optical microresonator.

[0069] Specifically, the optical microresonator has a high quality factor. The laser is coupled into the optical microresonator through the evanescent field effect, and four-wave mixing is used to generate equally spaced frequency components in the frequency domain. A mode-locked optical frequency comb is formed through the dual balance of gain and loss, dispersion and nonlinearity in the microresonator. The light in the microresonator will also produce backscattered light due to the surface roughness of the microresonator. The backscattered light is transmitted into the laser cavity along the waveguide to realize the self-injection locking process.

[0070] Further, if Figure 2 As shown in the figure, a thermistor structure is attached to the optical microresonator through a metal lift-off process. By applying a voltage across the tuning electrodes, the microresonator cavity length can be effectively adjusted, thereby shifting the spacing of the microresonator's resonant modes. On the optical waveguide, a thermistor structure is attached to the side near the input end face through a metal lift-off process. By applying a voltage across the tuning electrodes, the waveguide geometry and refractive index can be effectively adjusted, thereby changing the optical phase.

[0071] In a possible embodiment, the laser is not limited to a distributed feedback semiconductor laser, but may be a distributed Bragg reflector, a Fabry-Perot cavity multi-mode laser diode or other lasers.

[0072] In a possible embodiment, in addition to using the metal lift-off process, electrodes may be plated on the waveguide section and the microresonator section by deposition, sputtering, or the like.

[0073] In a possible embodiment, the micro-resonator structure etched on the photonic chip is not limited to Figure 2 The "finger" structure, such as Figure 3 、 4 As shown, single optical microresonator structures such as rings and vortex lines are all applicable to the optical frequency comb self-starting device and method proposed in the present invention, and electrode structures are attached to both the waveguide section and the optical microresonator section.

[0074] It's worth noting that the conditions for generating a mode-locked optical frequency comb primarily require that the pump power exceed the parametric oscillation threshold and that the laser pump mode be red-detuned (i.e., shifted toward longer wavelengths) relative to the microresonator's resonant mode. A larger detuning increases the spectral width of the generated optical frequency comb, but also significantly increases the required pump power. The pump power and the spectral width of the optical frequency comb are quadratically related. Due to the limited output power of the laser, coupling structure design is necessary to enhance the effective pump power.

[0075] Therefore, in addition to a single optical microresonator, the present invention utilizes a photonic chip with a resonantly coupled dual optical microresonator structure as the core component of the optical module. By introducing dual-resonator coupling to increase the effective pump power, a self-starting optical frequency comb with higher efficiency and wider spectral bandwidth can be achieved. Similar to the single microresonator structure, the resonantly coupled dual-resonator structure incorporates tuning electrodes on both microresonators, and adjusting the electrode voltage can alter the mode position relationship between the two microresonators.

[0076] In some possible embodiments of the present invention, the optical microresonator includes a first microresonator and a second microresonator coupled to each other, and the first microresonator and the second microresonator are both provided with a first microresonator tuning electrode. By jointly adjusting the control voltages of the two first microresonator tuning electrodes, the first microresonator and the second microresonator are coupled to achieve pump enhancement.

[0077] Specifically, the embodiment of the present invention provides an implementation of a dual optical microresonator resonant coupling structure, such as Figure 5 As shown, a self-starting optical microcomb with a larger spectral width is realized through a resonantly coupled dual optical microresonator structure. A second microresonator is introduced between the waveguide and the first microresonator. By adjusting the voltage of the microresonator tuning electrode, the second microresonator can produce a resonance enhancement effect, thereby increasing the effective pump power.

[0078] In some possible embodiments of the present invention, the optical microresonator includes a third microresonator and a fourth microresonator coupled to each other, and the fourth microresonator and the third microresonator are both provided with a second microresonator tuning electrode. By jointly adjusting the control voltages of the two second microresonator tuning electrodes, mode splitting is selectively applied to the pump mode of the third microresonator, so that when the resonant mode of the third microresonator resonates with the pump laser, the pump laser is simultaneously detuned in the far-infrared relative to the original position of the pump mode of the third microresonator.

[0079] Specifically, the embodiment of the present invention provides another implementation method of a dual optical microresonator resonant coupling structure, which realizes a more efficient self-starting optical microcomb through the resonant coupling dual optical microresonator structure. The resonant mode spacing of a single microresonator structure is determined by the resonator circumference and the anomalous dispersion of the waveguide. When the continuous laser pump mode is red-detuned to the pump resonance peak, it can excite the mode-locked optical frequency comb. However, excessive red detuning causes most of the pump light to fail to couple into the resonator and directly transmit the output, which is very inefficient. Figure 6 As shown in the figure, through the mutually coupled microresonator structure, it is possible to selectively apply mode splitting to the pump mode by adjusting the voltage of the microresonator tuning electrode, causing the pump mode to move independently while the other modes remain unchanged. This improvement allows the pump laser to be simultaneously detuned in the far-infrared relative to the original resonance peak position when resonating with the pump resonance peak. This allows most of the pump light to be coupled into the resonator while maintaining the same pumping conditions, significantly improving the efficiency of optical frequency comb generation.

[0080] The optical frequency comb self-starting device provided in an embodiment of the present invention adopts a microresonator backscattered light feedback path and a phase electrode tuning structure to achieve the formation and stable maintenance of a self-injection locked state; adopts a microresonator electrode and a laser current drive module to achieve dynamic wavelength tuning and stable output; adopts a dual microresonator resonant coupling structure to achieve pump enhancement through the mutually coupled microresonator structure, thereby increasing the bandwidth of the optical frequency comb, and enhances the pump light coupling efficiency through mode splitting, thereby solving the problems of large transmission loss and low efficiency of traditional single microresonators; through electrode integrated tuning, the microresonator and waveguide section are plated with metal electrodes, and dynamic mode matching is achieved through voltage tuning; it can integrate components such as lasers, silicon nitride photonic chips, isolators, and wavelength division multiplexers, and adopts compact packaging and modular integration to achieve portable packaging, supporting rapid deployment outside the laboratory (such as airborne and submarine exploration); the temperature control module and vibration-resistant packaging ensure long-term stability in outdoor environments, ensuring the highly robust design of the optical frequency comb self-starting device.

[0081] In some specific embodiments of the present invention, Figure 7As shown, this solution provides an optical frequency comb self-starting method, which is implemented by the optical frequency comb self-starting device provided by any of the above embodiments, and the method includes: Step 710: establishing an interlocking relationship between the laser and the optical microresonator through self-injection locking, and outputting an optical frequency comb signal and transmitting a pump light signal through the photonic chip; Step 720: Based on the optical frequency comb signal and the pump light signal, the pump current of the laser, the control voltage of the microresonator tuning electrode, and the control voltage of the waveguide phase tuning electrode are adjusted in a coordinated manner so that the photonic chip generates a mode-locked optical frequency comb signal of a target wavelength. Step 730: During the process of generating a mode-locked optical frequency comb signal at a target wavelength, determining whether a mode-locked signal exists based on the monitoring result of the optical frequency comb signal, and if it is determined that a mode-locked signal exists, determining the power corresponding to the mode-locked frequency comb signals at different wavelengths; Step 740: Based on the power corresponding to the target wavelength mode-locked state frequency comb signal and the mode-locked signal judgment result, the control voltage of the microresonator tuning electrode and the control voltage of the waveguide phase tuning electrode are adjusted so that the photonic chip automatically generates and outputs the target wavelength mode-locked state optical frequency comb signal.

[0082] Specifically, an embodiment of the present invention provides an implementation method for a self-starting method of an optical frequency comb, which automatically identifies the locked mode state through gradient analysis, continuous interval screening, and threshold discrimination, replacing the traditional manual monitoring of the spectrum or power. Continuous wavelength tuning is achieved through the coordinated adjustment of the laser current, microresonator tuning electrode voltage, and waveguide phase tuning electrode voltage. According to the target locked mode power, the microresonator tuning electrode voltage is automatically adjusted until the optical frequency comb monitoring signal is within the target power range, thereby achieving flexible spectrum switching.

[0083] In some possible implementations of the present invention, establishing an interlocking relationship between the laser and the optical microresonator by self-injection locking specifically includes: Outputting pump light through a laser, the pump light is introduced into the coupling waveguide of the photonic chip and coupled to the optical microresonator through the evanescent field effect; Part of the pump light is backscattered by the roughness of the optical microresonator surface and returns to the laser cavity along the coupling waveguide, generating a self-injection locking effect; When the initial detuning between the laser output mode and the optical microresonator is within a preset range and the backscattered light meets the feedback phase condition, the optical frequency comb signal output is achieved.

[0084] Specifically, an embodiment of the present invention provides an implementation method for generating an optical frequency comb signal by a self-injection locking method.

[0085] Specifically, the semiconductor laser is end-face coupled to a photonic chip engraved with an optical microresonator structure through a microlens. Light is transmitted from the waveguide input port of the photonic chip along the waveguide and coupled into the optical microresonator through the evanescent field effect at the coupling position. The optical microresonator generates backscattered light that is coupled to the waveguide and transmitted back to the semiconductor laser cavity, producing a self-injection locking effect. When the laser output mode and the initial detuning of the optical microresonator are within a certain range and the backscattered light meets the feedback phase condition, the system can achieve optical frequency comb output.

[0086] It is worth noting that self-injection locking establishes an interlocking relationship between the resonator mode and the laser mode, extending the tunable bandwidth from the original extremely short mode-locked signal length to the injection-locked bandwidth. The core parameters that need to be adjusted in the self-injection locking method are the feedback phase and the initial detuning of the laser output laser mode and the optical microresonator, while the optical frequency comb device can freely adjust the feedback phase and the initial detuning of the laser output laser mode and the optical microresonator, which is an important basis for the continuous wavelength tuning method of the present invention.

[0087] In some possible embodiments of the present invention, based on the pump light signal and the optical frequency comb signal, the pump current of the laser, the control voltage of the microresonator tuning electrode, and the control voltage of the waveguide phase tuning electrode are linked to generate a mode-locked optical frequency comb signal of a target wavelength, specifically including: Adjust the laser pump current to control the laser wavelength to the target wavelength, and scan the microresonator tuning electrode control voltage , determining whether a microresonator resonant mode exists according to the pump light signal; Adjust the waveguide phase tuning electrode control voltage , determining whether a mode-locked state exists according to the optical frequency comb signal; The power of different mode-locked states is marked, and the control voltage of the resonator tuning electrode is adjusted based on the target mode-locked state power to generate a target mode-locked state optical frequency comb signal.

[0088] Specifically, an embodiment of the present invention provides a method for generating an optical frequency comb signal that can achieve continuous tunable wavelength, outputs a wavelength-tunable optical frequency comb signal, dynamically adapts to application requirements, can cover a specific spectral range in the field of optical communication applications, and dynamically adjusts the output wavelength according to the requirements of the back-end system, such as dynamically allocating channels in a wavelength division multiplexing system, realizing real-time multi-component analysis through tuning scanning in a precision spectral analysis clock, and matching different atomic transition frequencies in an optical clock system.

[0089] Specifically, the laser current is adjusted to control the laser to the target wavelength, and the microresonator tuning electrode control voltage is scanned. , judging whether there is a micro-resonator resonant mode according to the first monitoring signal; adjusting the waveguide phase tuning electrode control voltage , calling the mode-locked signal judgment program to judge whether the mode-locked state exists according to the second monitoring signal; marking different mode-locked state powers, and calling the mode-locked optical frequency comb controllable generation program based on the target mode-locked state power to realize the target mode-locked state optical frequency comb signal.

[0090] In a possible embodiment, Figure 8 As shown, the microresonator tuning electrode controls the microresonator heater structure, and the waveguide phase tuning electrode controls the waveguide heater structure.

[0091] In a possible embodiment, Figure 8 As shown, based on the pump light signal and the optical frequency comb signal, the pump current of the laser, the control voltage of the microresonator electrode, and the control voltage of the waveguide phase electrode are linked to adjust to generate a mode-locked optical frequency comb signal of a target wavelength, specifically including: S0. Get the target wavelength parameters set by the user , laser initial temperature , laser initial current , setting the first photodetector to collect the pump light signal beacon in real time, and the second photodetector to collect the optical frequency comb monitoring signal in real time; S1, adjust the laser current to control the laser to the target wavelength; S2, the micro-resonator tuning electrode control voltage terminal inputs a triangle wave voltage scanning signal , center voltage S3, judging whether there is a micro-resonator resonance mode according to the first photodetector signal, if there is no micro-resonator resonance mode, go to step S5, if there is a micro-resonator resonance mode, go to step S6 S5. Adjust the center voltage of the triangular wave voltage scanning signal at the micro-resonator tuning electrode control voltage terminal , go to step S3; S6, control voltage to turn on the waveguide phase tuning electrode , input DC voltage signal; S7, judging whether a locked mode exists according to the signal of the second photoelectric detector, if the locked mode does not exist, go to step S8, if the locked mode exists, go to step S9; S8. Adjust the control voltage of the waveguide phase tuning electrode , go to step S6; S9, recording the power in different mode-locked states and maintaining the control voltage output of the current waveguide phase tuning electrode; S10, turn off the triangular wave voltage scanning signal at the micro-resonator tuning electrode control voltage terminal, and maintain the voltage is the peak value of the triangle wave signal, DC output; S14, judging whether the mode-locked state is controllably generated based on the second photodetector signal, and if it is judged that the mode-locked state is not controllably generated, adjusting the microresonator tuning electrode control voltage , then go to step S13; if it is determined that the controllable generation of the mode-locked state has been achieved, the generation of the mode-locked state optical frequency comb signal of the target wavelength is completed.

[0092] Furthermore, a single optical frequency comb source achieves multi-scenario coverage and reduces hardware redundancy. Continuously tunable optical frequency comb signals enable flexible wavelength switching with a single device. In precision measurements, wavelength scanning enables real-time detection of characteristic absorption lines of multiple components. In optical communications, this can cover multiple wavelength channels and dynamically adjust wavelengths without replacing equipment, improving bandwidth utilization and reducing system design complexity and cost. In precision measurements, tuning to a specific wavelength significantly improves the signal-to-noise ratio, enhancing measurement accuracy and sensitivity.

[0093] In some possible embodiments of the present invention, after completing the generation of the target wavelength mode-locked optical frequency comb signal, the method further includes finely adjusting the output wavelength, specifically including: According to the target wavelength, adjusting the control voltage of the microresonator tuning electrode, the pump current of the laser, and the control voltage of the waveguide optical phase tuning electrode; During the adjustment process, whether the mode-locked state is maintained is determined according to the optical frequency comb signal.

[0094] Specifically, an embodiment of the present invention provides a specific method for fine-tuning the output wavelength, adjusting the microresonator tuning electrode control voltage and the laser pump current according to the target wavelength, adjusting the waveguide phase tuning electrode control voltage and judging whether the mode-locked state is maintained based on the second monitoring signal.

[0095] In a possible embodiment, see also Figure 8 As shown, after completing the generation of the target wavelength mode-locked optical frequency comb signal, the method specifically includes: S15, determining whether fine adjustment of the current wavelength is required; S16. If the current wavelength needs to be fine-tuned, the micro-resonator tuning electrode control voltage is adjusted according to the wavelength change. ; S17, in-phase adjustment of pump current; S18, adjust the waveguide phase tuning electrode control voltage Output; S19, judging whether the mode-locked state is maintained according to the signal of the second photodetector, and if so, completing the self-start of the optical frequency comb in the mode-locked state; if not, proceeding to step S20; Waveguide phase S20, adjust the control voltage of the waveguide phase tuning electrode, and go to step S18.

[0096] In a possible embodiment, continuous wavelength tunability is achieved based on multiple degrees of freedom of parameters such as microresonator electrode voltage, laser pump current, temperature, and phase electrode voltage. The output wavelength of the semiconductor laser can be tuned over a wide range through current parameters. When the entire system is in a self-injection locked state, the microresonator electrode voltage is adjusted to achieve microresonator mode tuning, thereby changing the wavelength of the optical frequency comb signal. After the wavelength is adjusted, the phase drift generated during the wavelength adjustment process is adjusted by adjusting the waveguide phase electrode voltage to recover the corresponding optical frequency comb signal. In particular, when the microresonator electrode voltage is changed, the laser pump current can be changed accordingly, thereby extending the self-injection locking bandwidth to cover the free spectral range (FSR) of the microresonator.

[0097] It is worth noting that the preferred method for tuning the wavelength is to change the pump current of the semiconductor laser. Changing the temperature of the semiconductor laser can also achieve a wide range of wavelength tuning. However, the optimal operating temperature range of the semiconductor laser is around 20℃-30℃. Unsuitable operating temperature can easily cause multi-mode lasing of the semiconductor laser. Therefore, temperature-tuned wavelength is a suboptimal choice.

[0098] In some possible implementations of the present invention, determining whether a mode-locked signal exists based on the monitoring result of the optical frequency comb signal specifically includes: Obtaining a voltage signal array corresponding to the optical frequency comb signal to be determined; Determine the global maximum value in the voltage signal array, The global maximum value is used as the starting point of the effective voltage signal to be analyzed, the voltage signal array is segmented by the first-order difference of the effective data group, and each segment of data in the voltage signal array is marked as being in a mode-locked state by the continuous interval length, data segment slope, and data segment amplitude of each segment.

[0099] In a possible embodiment, Figure 9 As shown, the determining whether a mode-locked signal exists based on the monitoring result of the optical frequency comb signal specifically includes: Input the voltage signal array to be judged; Setting parameter gradient threshold , interval length threshold , slope threshold , amplitude threshold , ; Search for the global maximum value in the voltage signal array to determine the starting point of the valid data segment; Calculate the first-order difference of valid data segments , and divide the continuous data segments by threshold comparison, marking the data segment length ; Compare and The size of , then mark the data segment as a non-mode-locked signal; like , calculate the slope of the starting and ending points of the continuous data segment ; Compare and The size of , then mark the data segment as a non-mode-locked signal; like , calculate the peak-to-peak value of continuous data segments With minimum value ; Compare and The size of and size; like ,and , then the data segment is marked as a mode-locked signal, otherwise, the data segment is marked as a non-mode-locked signal, and the mode-locked signal judgment is completed.

[0100] Specifically, the embodiment of the present invention provides an implementation method for identifying a mode-locked signal, wherein the acquisition system receives an optical frequency comb monitoring signal, that is, Figure 1 The second monitoring signal in the embodiment of the present invention is used to calculate the power and spectrum of the monitoring signal, and the mode-locked signal is identified by gradient analysis and threshold marking based on the power and spectrum data obtained by the calculation.

[0101] Specifically, this embodiment provides an implementation method for determining whether a mode-locked signal exists based on the monitoring results of an optical frequency comb signal. By determining the global maximum value of the optical frequency comb signal, the interference of the Turing state and the modulation instability state is avoided. The data group is segmented by the first-order difference of the valid data group, and the length of the continuous interval, the slope of the data segment, and the amplitude of the data segment are used to mark whether the data segment is in the mode-locked state. The mode-locked signal is as follows: Figure 10 As shown in Figure 2, the optical frequency comb signals output by different mode-locked states exhibit different characteristics in the spectrum, such as Figure 11 The mode-locking signal is identified by analyzing the optical frequency comb monitoring signal.

[0102] In some possible embodiments of the present invention, the control voltage of the microresonator tuning electrode and the control voltage of the waveguide optical phase tuning electrode are adjusted based on the power corresponding to the target wavelength mode-locked state frequency comb signal and the mode-locked signal judgment result to complete the automatic generation of the target wavelength mode-locked state optical frequency comb signal, including: Based on the power and mode-locked signal judgment results corresponding to the frequency comb signal in the target wavelength mode-locked state, the control voltage of the microresonator tuning electrode and the control voltage of the waveguide phase tuning electrode are adjusted so that the power and peak-to-peak value of the optical frequency comb signal are within the threshold range, thereby completing the automatic generation of the optical frequency comb signal in the target wavelength mode-locked state.

[0103] Specifically, the embodiment of the present invention provides an implementation method for automatically and controllably generating a mode-locked optical frequency comb signal. Combined with an automatic recognition method for the mode-locked signal, the automatic and controllably generating of the mode-locked optical frequency comb signal is achieved by adjusting the voltage of the microresonator tuning electrode to the target range under the premise of determining the target mode-locked state. Based on the power corresponding to the target wavelength mode-locked frequency comb signal and the mode-locked signal judgment result, the control voltage of the microresonator tuning electrode and the control voltage of the waveguide phase tuning electrode are adjusted so that Figure 1 The power and peak-to-peak value of the second monitoring signal are in the threshold range, completing the automatic generation of the optical frequency comb signal in the target wavelength mode-locked state.

[0104] In a possible embodiment, Figure 12 As shown, the control voltage of the microresonator tuning electrode and the control voltage of the waveguide phase tuning electrode are adjusted based on the power corresponding to the target wavelength mode-locked state frequency comb signal and the mode-locked signal judgment result, thereby completing the automatic generation of the target wavelength mode-locked state optical frequency comb signal, including: Get the power corresponding to different locking states , set the error range , peak-to-peak ; According to the pre-calibrated power Calibrate different clamping states; Set the mode-locking state signal to be generated; Get the current optical frequency comb signal power and peak-to-peak ; judge whether it is established; like If this is not true, adjust the control voltage of the microresonator tuning electrode to regain the current optical frequency comb signal power. and peak-to-peak , and judge again whether it is established; like If established, then compare and size; like , then it is determined that the target wavelength mode-locked state optical frequency comb signal is automatically generated, otherwise, the control voltage of the microresonator tuning electrode is adjusted to re-acquire the current optical frequency comb signal power and peak-to-peak , and judge again Is it true?

[0105] Through the above-mentioned settings, the present invention proposes a completely self-starting optical frequency comb generation method and realizes the controllable generation of optical frequency comb signals in the locked state, which greatly improves the usability of optical frequency comb equipment, removes the professional knowledge threshold and manual intervention and adjustment restrictions for obtaining optical frequency comb signals, and allows different application fields and application scenarios to have barrier-free access to optical frequency comb signals.

[0106] Specifically, in the self-starting logic of the optical frequency comb, in order to achieve the controllable and fully automatic generation of the optical frequency comb signal in the mode-locked state, the core is the mode-locked signal judgment and mode-locked state generation. Figure 9 As shown in the figure, first, by selecting the global maximum value in the voltage signal array, the interference of Turing state and modulation instability is avoided, the first-order difference of the valid data group is calculated, the data group is segmented, and the length of the continuous interval, the slope of the start and end points of the data segment and the amplitude of the data segment are used to mark whether the data segment is in the mode-locked state. The mode-locked signal is as follows: Figure 10 As shown in Figure 2, the optical frequency comb signals output by different mode-locked states exhibit different characteristics in the spectrum, such as Figure 11 The mode-locking signal is identified by analyzing the optical frequency comb monitoring signal.

[0107] Furthermore, after obtaining the mode-locking signal data, the controllable generation of the mode-locking state can be achieved, such as Figure 12 As shown in the figure, the power and peak-to-peak value of each mode-locked state can be analyzed based on the different mode-locked states obtained during the mode-locked signal determination process. The system adjusts the microresonator electrode voltage according to the specified target mode-locked state and compares the set peak-to-peak threshold with the power until the optical frequency comb signal in the specified mode-locked state is generated.

[0108] Based on any of the above embodiments, a tightly packaged, highly robust optical frequency comb device is provided, which can be quickly deployed in an environment outside the laboratory, significantly improving its application potential in actual scenarios outside the laboratory, breaking through the laboratory limitations of traditional optical frequency combs, and becoming a reliable light source for military and civilian scenarios such as high-speed communications, submarine exploration, and analog computing, with broad prospects for engineering applications. Through optical structure design, a broadband self-starting optical frequency comb is provided. By designing a mutually coupled microresonator structure, the limitation of the laser output capacity on the optical frequency comb spectrum width is effectively solved. Through optical structure design, a more efficient self-starting optical frequency comb is provided. By designing a mutually coupled microresonator structure, the pump mode is selectively split by adjusting the microresonator electrode voltage, so that when the pump laser resonates with the pump resonance peak, the far-infrared detuning of the pump laser relative to the original resonance peak position can be achieved at the same time, and most of the pump light energy is coupled into the microresonator while maintaining the same pumping conditions, significantly improving the efficiency of optical frequency comb generation.

[0109] The optical frequency comb self-starting device and method provided in the embodiments of the present invention achieve fully automatic operation through intelligent algorithms (locked mode state judgment and parameter collaborative tuning), solving the problem of traditional technology relying on manual labor and low efficiency; through the dual micro-resonator structure, compact packaging and high-precision tuning components, it breaks through the bottleneck of low integration and fixed wavelength.

[0110] The optical frequency comb self-starting method automatically identifies the mode-locked state through gradient analysis, threshold marking, and continuous interval screening, replacing traditional manual monitoring of spectrum or power. A control system, such as a single-chip microcontroller, adjusts parameters such as the laser pump current and microresonator electrode voltage in real time, lowering the professional barrier to entry. By linking the laser current, microresonator voltage, and phase electrode, the method overcomes the traditional limitations of mode-locked signal length and achieves continuous wavelength tuning. Voltage changes in the waveguide phase electrode adjust the drift of backscattered light, maintaining the self-injection locked state and ensuring stability during the tuning process. Based on the target mode-locked state, power analysis automatically adjusts the voltage to the target range, enabling flexible spectrum switching. The optical frequency comb self-starting device utilizes a dual-microresonator resonant coupling structure. Mode splitting enhances pump light coupling efficiency and expands the optical frequency comb spectral width, addressing the high transmission loss and low efficiency of traditional single microresonators. Metal-plated electrodes are used on the microresonator and waveguide segments, enabling dynamic mode matching through voltage tuning.

[0111] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0112] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An optical frequency comb self-starting device, characterized in that: Including lasers, photonic chips, control systems and acquisition systems; The laser is used to generate a pump light signal; The photonic chip is used to output an optical frequency comb signal and transmit a pump light signal. The photonic chip includes an integrated optical microresonator and a coupled waveguide. The optical microresonator is provided with a microresonator tuning electrode, and the coupled waveguide is provided with a waveguide phase tuning electrode. The acquisition system is used to monitor the pump light signal and the optical frequency comb signal in real time; The control system is connected to the laser, the microresonator tuning electrode, the waveguide phase tuning electrode, and the acquisition system, respectively. The control system is used to automatically identify a mode-locked signal based on monitoring results of the pump light signal and the optical frequency comb signal fed back by the acquisition system, and adjust the pump current of the laser, the control voltage of the microresonator tuning electrode, and the control voltage of the waveguide phase tuning electrode based on the mode-locked signal identification result, so that the photonic chip generates a mode-locked optical frequency comb signal of a target wavelength.

2. The optical frequency comb self-starting device according to claim 1, characterized in that: The apparatus also includes a wavelength division multiplexer and a beam splitter; The laser inputs the pump light signal into the photonic chip coupling waveguide; the pump light signal is coupled to the optical microresonator through the evanescent field effect, and the backscattered light generated by the optical microresonator is coupled to the coupling waveguide and transmitted back to the laser cavity, thereby generating a self-injection locking effect; The wavelength division multiplexer is used to divide the output signal of the received photonic chip into a pump light signal and an optical frequency comb signal, and output the pump light signal as the first monitoring signal to the acquisition system; The beam splitter is used to receive the optical frequency comb signal, split the optical frequency comb signal into an optical frequency comb output signal and a second monitoring signal according to a preset ratio, and output the second monitoring signal to the acquisition system.

3. The optical frequency comb self-starting device according to claim 2, characterized in that: The control system includes a tunable constant current source, a multi-channel electrode driving module, a temperature control module and a main control chip; The tunable constant current source is used to provide an adjustable laser pump current for the laser; The multi-channel electrode driving module includes a micro-resonator tuning electrode driving module and a waveguide phase tuning electrode driving module, wherein the micro-resonator tuning electrode driving module is used to tune the resonant mode of the optical micro-resonator, and the waveguide phase tuning electrode driving module is used to adjust the optical phase of the coupled waveguide; The temperature control module is used to control the operating temperature of the laser; The main control chip integrates a continuously tunable optical frequency comb self-starting algorithm, which is used to perform mode-locking signal judgment based on the first monitoring signal and the second monitoring signal received in real time, and automatically adjust the pump current, multi-channel electrode voltage driving module and temperature control module according to the mode-locking signal judgment result to generate a mode-locked state frequency comb signal of the target wavelength.

4. The optical frequency comb self-starting device according to any one of claims 1 to 3, characterized in that: The optical microresonator includes a first microresonator and a second microresonator coupled to each other. The first microresonator and the second microresonator are both provided with a first microresonator tuning electrode. By adjusting the control voltages of the two first microresonator tuning electrodes in a linked manner, the first microresonator and the second microresonator are coupled to achieve pump enhancement.

5. The optical frequency comb self-starting device according to any one of claims 1 to 3, characterized in that: The optical microresonator includes a third microresonator and a fourth microresonator coupled to each other. The fourth microresonator and the third microresonator are both provided with a second microresonator tuning electrode. By adjusting the control voltages of the two second microresonator tuning electrodes in a linked manner, mode splitting is selectively applied to the pump mode of the third microresonator. When the resonant mode of the third microresonator resonates with the pump laser, the pump laser is simultaneously detuned in the far-infrared relative to the original position of the pump mode of the third microresonator.

6. A method for self-starting an optical frequency comb, characterized in that: The method is implemented by the optical frequency comb self-starting device according to any one of claims 1 to 5, and comprises: The interlocking relationship between the laser and the optical microresonator is established through self-injection locking, and the optical frequency comb signal and the transmission pump light signal are output through the photonic chip; Based on the optical frequency comb signal and the pump light signal, the pump current of the laser, the control voltage of the microresonator tuning electrode, and the control voltage of the waveguide phase tuning electrode are adjusted in a coordinated manner so that the photonic chip generates a mode-locked optical frequency comb signal of a target wavelength; In the process of generating a mode-locked optical frequency comb signal of a target wavelength, determining whether a mode-locked signal exists based on a monitoring result of the optical frequency comb signal, and if it is determined that the mode-locked signal exists, determining the power corresponding to the mode-locked frequency comb signals of different wavelengths; Based on the power and mode-locked signal judgment results corresponding to the target wavelength mode-locked state frequency comb signal, the control voltage of the microresonator tuning electrode and the control voltage of the waveguide phase tuning electrode are adjusted so that the photonic chip automatically generates and outputs the target wavelength mode-locked state optical frequency comb signal.

7. The optical frequency comb self-starting method according to claim 6, characterized in that: The establishing of an interlocking relationship between the laser and the optical microresonator by self-injection locking specifically includes: Outputting pump light through a laser, the pump light is introduced into the coupling waveguide of the photonic chip and coupled to the optical microresonator through the evanescent field effect; Part of the pump light is backscattered by the roughness of the optical microresonator surface and returns to the laser cavity along the coupling waveguide, generating a self-injection locking effect; When the initial detuning between the laser output mode and the optical microresonator is within a preset range and the backscattered light meets the feedback phase condition, the optical frequency comb signal output is achieved.

8. The optical frequency comb self-starting method according to claim 6, characterized in that: Based on the pump light signal and the optical frequency comb signal, the pump current of the laser, the control voltage of the microresonator tuning electrode, and the control voltage of the waveguide phase tuning electrode are adjusted in a coordinated manner to generate a mode-locked optical frequency comb signal of a target wavelength, specifically comprising: Adjust the laser pump current to control the laser wavelength to the target wavelength, and scan the microresonator tuning electrode control voltage , determining whether a microresonator resonant mode exists according to the pump light signal; Adjust the waveguide phase tuning electrode control voltage , determining whether a mode-locked state exists according to the optical frequency comb signal; The power of different mode-locked states is marked, and the control voltage of the resonator tuning electrode is adjusted based on the target mode-locked state power to generate a target mode-locked state optical frequency comb signal.

9. The optical frequency comb self-starting method according to claim 8, characterized in that: After completing the generation of the mode-locked optical frequency comb signal at the target wavelength, the method further includes finely adjusting the output wavelength, specifically comprising: According to the target wavelength, adjusting the control voltage of the microresonator tuning electrode, the pump current of the laser, and the control voltage of the waveguide phase tuning electrode; During the adjustment process, whether the mode-locked state is maintained is determined according to the optical frequency comb signal.

10. The optical frequency comb self-starting method according to claim 6, characterized in that: The determining whether a mode-locked signal exists based on the monitoring result of the optical frequency comb signal specifically includes: Obtaining a voltage signal array corresponding to the optical frequency comb signal to be determined; Determine the global maximum value in the voltage signal array, The global maximum value is used as the starting point of the effective voltage signal to be analyzed, the voltage signal array is segmented by the first-order difference of the effective data group, and each segment of data in the voltage signal array is marked as being in a mode-locked state by the continuous interval length, data segment slope, and data segment amplitude of each segment.

11. The optical frequency comb self-starting method according to claim 10, characterized in that: The method adjusts the control voltage of the microresonator tuning electrode and the control voltage of the waveguide phase tuning electrode based on the power corresponding to the target wavelength mode-locked state frequency comb signal and the mode-locked signal judgment result to automatically generate the target wavelength mode-locked state optical frequency comb signal, including: Based on the power and mode-locked signal judgment results corresponding to the frequency comb signal in the target wavelength mode-locked state, the control voltage of the microresonator tuning electrode and the control voltage of the waveguide phase tuning electrode are adjusted so that the power and peak-to-peak value of the optical frequency comb signal are within the threshold range, thereby completing the automatic generation of the optical frequency comb signal in the target wavelength mode-locked state.

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