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CN-116316036-B - Control method, storage medium and terminal for Brillouin laser Kerr optical frequency comb based on orthogonal polarization mode

CN116316036BCN 116316036 BCN116316036 BCN 116316036BCN-116316036-B

Abstract

The invention discloses a control method, a storage medium and a terminal of a Brillouin laser Kerr optical frequency comb based on an orthogonal polarization mode, and the control method, the storage medium and the terminal are based on a control module; the method comprises an initial control step and a secondary pumping control step, wherein the secondary pumping control step is used for sending a second control command to the adjustable wavelength laser, and further adjusting the blue shift speed and the optical power of the pumping laser wavelength based on monitoring data of a fourth optical detector for monitoring the stimulated Brillouin laser state of the cross polarization TM mode after optical polarization beam splitting until the Kerr optical frequency comb state appears. According to the invention, the Kerr optical frequency comb is formed by generating the stimulated Brillouin laser secondary pumping in the orthogonal polarization mode, specific comb teeth of the optical frequency comb are filtered, and the filtered optical wave signal is subjected to beat frequency to obtain the required microwave signal output.

Inventors

  • PU JIAN

Assignees

  • 四川泊微科技有限公司

Dates

Publication Date
20260505
Application Date
20211019

Claims (8)

  1. 1. The control method based on the orthogonal polarization mode Brillouin laser Kerr optical frequency comb is based on a control module, and is characterized by comprising the following steps: The initial control step comprises the steps of sending a first control command to the adjustable wavelength laser, setting the input pumping laser wavelength at the blue detuning position of the resonant peak wavelength corresponding to the TE mode polarized photon of the silicon nitride micro-ring cavity, and gradually increasing the wavelength blue shift to enable the pumping laser to be close to the resonant peak based on the monitoring data of a second optical detector for monitoring the working state of the pumping laser penetrating through the output port of the silicon nitride micro-ring cavity and a third optical detector for monitoring the working state of the resonant light in the output port of the lower path of the silicon nitride micro-ring cavity; A second pump control step of sending a second control command to the adjustable wavelength laser, and further adjusting the blue shift speed and the optical power of the pump laser wavelength based on the monitoring data of a fourth optical detector for monitoring the stimulated Brillouin laser state of the cross polarization TM mode after the optical polarization beam splitting until the Kerr optical frequency comb state appears; In the control method, the connection relation between the control module and the external component comprises: The wavelength-adjustable laser receives the pump laser with corresponding wavelength and power commanded to be output by the control module; an optical amplifier for amplifying the pump laser; The optical circulator is used for receiving the amplified pump laser at the first port; the optical input end receives pumping laser through the second port of the optical circulator, and outputs mixed laser to the second port of the optical circulator together with the pumping laser after the brillouin laser is excited in the cavity; the optical polarization beam splitter receives the mixed laser output by the third port of the optical circulator, filters pumping laser in the mixed laser and outputs split Brillouin laser; the photon filtering module receives the Brillouin laser of the optical polarization beam splitter, selects a corresponding frequency interval and outputs a filtered photon signal; the first optical detector receives the photon signals and outputs microwave signals after beat frequency; The input end of the second optical detector is connected with a through output port of the silicon nitride micro-ring cavity, the output end of the second optical detector is connected with the control module, and the working state of pumping laser is monitored; The input end of the third optical detector is connected with the lower output port of the silicon nitride micro-ring cavity, the output end of the third optical detector is connected with the control module, and the working state of the third optical detector is monitored and controlled by the resonance light in the silicon nitride micro-ring cavity; The input end of the fourth optical detector is connected with an optical splitter positioned between the optical polarization beam splitter and the photon filtering module, and the output end of the fourth optical detector is connected with the controller and is used for monitoring the working state of the Kerr optical frequency comb in the micro-ring cavity; The silicon nitride micro-ring cavity forms a Kerr optical frequency comb through the control module to the secondary pumping of the wavelength-adjustable laser.
  2. 2. The method for controlling the Brillouin laser Kerr optical frequency comb based on the orthogonal polarization mode according to claim 1, wherein the photon filtering module comprises an independent photon filter with a spectral line interval FSR Filtering , the photon filter filters an orthogonal mode Brillouin laser Kerr optical frequency comb signal, FSR Filtering =M×FSR brillouin optical fiber is an integer, M is an integer, and FSR brillouin optical fiber is a resonance peak spectral line interval of a silicon nitride micro-ring cavity.
  3. 3. The control method based on the Brillouin laser Kerr optical frequency comb in the orthogonal polarization mode of claim 1, wherein the photon filtering module comprises an optical splitter, a first photon filter, a second photon filter and an optical combiner, the optical splitter receives laser of the optical polarization beam splitter and splits 50:50 into two paths of light, the two paths of light enter the first photon filter and the second photon filter respectively, corresponding Kerr optical frequency comb tooth photon signals are selected according to microwave signals in a required wave band, and the two paths of photon signals are input into the first optical detector after optical combination; Wherein the line spacing FSR Filtering of the first and second photon filters is large and requires a signal response bandwidth greater than the first photodetector, and FSR Filtering is not an integer multiple of FSR brillouin optical fiber of the kerr optical frequency comb.
  4. 4. The control method based on the Brillouin laser Kerr optical frequency comb in the orthogonal polarization mode according to claim 2 or 3 is characterized in that the resonance peak frequency of the laser in the TE mode and the resonance peak frequency of the laser in the TM mode in the silicon nitride micro-ring cavity are distributed at intervals of free spectrum interval FSR brillouin optical fiber GHz, n is an integer, the resonance peak frequency of the laser in the orthogonal polarization TE mode and the resonance peak frequency of the laser in the TM mode are slightly spaced apart, and the difference is Deltav MHz; Based on the frequency offset of pump light laser Brillouin laser in the silicon nitride micro-ring cavity being f ΔSBL , FSR brillouin optical fiber value of the silicon nitride micro-ring cavity is designed to be (f ΔSBL +Δυ）=m*FSR brillouin optical fiber , m is an integer; based on the FSR brillouin optical fiber value, the size of the silicon nitride micro-ring cavity is designed according to the formula FSR=delta lambda=lambda 2 /n g L, wherein lambda is the wavelength of light, n g is the group refractive index of the waveguide, and L is the length of the optical micro-cavity, namely the length of the silicon nitride micro-ring cavity.
  5. 5. The method for controlling the Brillouin laser Kerr optical frequency comb based on the orthogonal polarization mode according to claim 4 is characterized in that after the FSR brillouin optical fiber is determined, the wavelength of a Brillouin gain region is designed to overlap with the resonance peak of a silicon nitride micro-ring cavity of a TM polarized photon comb tooth FSR brillouin optical fiber , the peak of the wavelength of the Brillouin gain region is designed to be located at a position slightly offset from red of the resonance peak wavelength, a corresponding TE polarized photon is selected as the center wavelength of an input pumping light according to the value of the Brillouin frequency shift f ΔSBL , and the TM mode polarized photon is optimized to be anomalous dispersion in a BGS wavelength region of the Brillouin gain spectrum through dispersion engineering design.
  6. 6. The method for controlling a Brillouin laser Kerr optical frequency comb based on an orthogonal polarization mode as set forth in claim 5, wherein said tunable wavelength laser is a 1550nm communication band laser, a photon signal obtained by said photon filtering module is a Ka band, m is 4, f ΔSBL has a value of 11, and M is 12 or 13.
  7. 7. A storage medium having stored thereon computer instructions, wherein the computer instructions when executed perform the steps of a control method based on an orthogonal polarization mode Brillouin laser Kerr optical frequency comb as set forth in any one of claims 1 to 6.
  8. 8. A terminal comprises a memory and a processor, wherein the memory stores computer instructions capable of running on the processor, and the terminal is characterized in that the processor executes the steps of the control method based on the Brillouin laser Kerr optical frequency comb with the orthogonal polarization mode according to any one of claims 1-6 when the processor runs the computer instructions.

Description

Control method, storage medium and terminal for Brillouin laser Kerr optical frequency comb based on orthogonal polarization mode Technical Field The invention relates to the field of microwaves, in particular to a control method, a storage medium and a terminal of a Brillouin laser Kerr optical frequency comb based on an orthogonal polarization mode. Background The modern radar and microwave communication system all need to transmit and receive microwave signals, a microwave local oscillation signal source is used in the transmitter and the receiver, the general transmitting signals in the transmitting channel direction are mixed with the local oscillation signals and then are transmitted after power amplification, the receiving channels generally receive signals and the local oscillation signals and are mixed to obtain intermediate frequency signals and then are subjected to detection processing to extract needed information, therefore, the microwave local oscillation signal source in the modern radar and microwave communication system is indispensable, and the generation of the local oscillation signals with high frequency spectrum purity and low phase noise is always one pursuing target of the modern radar and communication system. Generally, the quality of the microwave signal generated by the microwave oscillator depends on the energy storage performance of the oscillation cavity, and to generate a high quality microwave signal, an energy storage unit with high Q value and low loss is required. Current microwave oscillators are mostly based on electronic (e.g. dielectric oscillators) and acoustic (e.g. crystal oscillators) energy storage elements. When these elements operate at frequencies above GHz, the energy storage characteristics are severely degraded, and the phase noise and spectral purity of the generated high-frequency microwaves are also degraded. In order to meet the requirements of generation, transmission and processing of high-frequency and ultra-wideband signals in the microwave field, microwave photonics generates and processes microwave radio-frequency signals by utilizing the advantages of large bandwidth and electromagnetic interference resistance of photon technology, can generate signals with high frequency spectrum purity of several GHz and hundreds of GHz and low phase noise, shows special technical advantages in microwave/millimeter wave frequency bands, and has excellent phase noise performance. Optical microcavities such as a traditional Fabry-Perot (F-P) cavity and an all-solid-state dielectric whispering gallery mode microcavity have stable high-Q resonant modes, and are combined with the high-Q microcavity through a continuous wave pump laser, so that the novel photonic microwave technology can be used for generating high-quality microwave signals, currently, an OEO photoelectric oscillator product which realizes Ka-band 35GHz frequency output by combining a DFB laser with a magnesium fluoride crystal whispering gallery mode resonant cavity through narrow linewidth output by a company of OEwaves is available, and also discloses a Kerr nonlinear effect of the magnesium fluoride crystal whispering gallery mode resonant cavity, a Kerr optical frequency comb is generated by pumping excitation of the DFB laser, and 10GHz microwave signal output of ultralow phase noise is obtained through beat frequency of optical frequency comb signals. The existing photonic microwave scheme for generating microwave signals by using the optical microcavity has the main problems that the optical microcavity such as an F-P cavity is large in size, difficult to integrate, high in manufacturing cost and high in assembly requirement of a cavity mirror with high reflectivity, and the whispering gallery mode resonant cavity of dielectric materials such as magnesium fluoride and silicon base is difficult to process, the precision requirement of processing equipment is particularly high, in addition, the optical assembly and debugging are difficult, the production process is complex and the like. Along with the development of silicon-based integrated photonics in recent years, the micro-ring cavity design based on a silicon nitride waveguide attracts more and more attention, the Kerr nonlinear effect of the micro-ring cavity of the through annular waveguide based on silicon nitride is researched relatively, the related scheme of generating 10GHz microwave signals after the Kerr optical frequency comb is excited by the micro-ring cavity based on silicon nitride, but still the technical problems still exist, such as the pumping excitation of high-power communication band laser signals is needed, the noise performance of a high-power DFB laser is poor, the noise performance of the output light of the pumping laser can have direct influence on the final beat frequency microwave signals, so that the system is difficult to obtain microwave signal output with better phase noise performance, and in addition, in