275 results about "Frequency stabilization" patented technology

The invention discloses an SF6 gas leakage detection method and system based on a photoacoustic spectrum analyzer, and the method comprises the steps: arranging a sampling end to collect an SF6 gas sample, and obtaining stable gas input through constant-current sampling and steady-state pretreatment; steady-state gas is guided into the photoacoustic spectrum analyzer, and resonance frequency stabilization and signal amplification output are achieved through the self-tuning unit; executing double-microphone differential detection and digital filtering processing, and outputting a stable SF6 detection signal with a high signal-to-noise ratio; performing time calibration, abnormity elimination and consistency processing on the detection signal to generate standardized detection data; inputting the standardized data to a Transform model, and performing inversion to generate an SF6 leakage source position and a diffusion path; and displaying an inversion result on a monitoring interface, triggering a sound-light alarm when the inversion result exceeds a limit, and uploading the inversion result to a cloud monitoring platform. According to the invention, the intelligent photoacoustic spectrum system combining photoacoustic-fluid steady-state control and self-tuning detection is constructed, so that high-sensitivity detection and accurate positioning of SF6 gas leakage are realized.

The invention discloses a laser frequency stabilization system based on Faraday anomalous dispersion atomic filtering, which is used for carrying out frequency stabilization on phase modulation multi-sideband laser, and comprises a frequency doubling laser unit which is configured to comprise a fundamental frequency seed light source, an electro-optical modulator, a fundamental frequency amplifier and a frequency doubling crystal; the light splitting module unit is configured to split the frequency doubling light into a main output light path and a monitoring light path; the atomic optical rotation filter is located on the monitoring light path and is configured to maintain the purity of the frequency-stabilized laser spectrum through purification treatment under the control of the axial magnetic field and the temperature; the frequency stabilization unit is configured to be a frequency stabilization light path and a servo system, and the frequency stabilization light path is used for obtaining laser frequency information and generating an error signal; the servo system is used for controlling the frequency of the fundamental frequency seed light source according to the error signal feedback. According to the laser frequency stabilization system provided by the invention, the spectrum purification and frequency stabilization precision can be improved, so that high-frequency stability locking is realized.

The invention discloses an intelligent diagnosis system for power utilization abnormal information acquisition, particularly relates to the technical field of power system monitoring, and is used for solving the problems of waveform distortion and broadening caused by transmission line distribution parameters in the long-distance wired transmission process of an existing system. The system collects abnormal characteristic waveform data through a distributed intelligent terminal, selects a characteristic harmonic component in the power frequency voltage of a power line to construct an inherent test signal, extracts the envelope form similarity of a response signal and the test signal through envelope analysis as a first distortion evaluation index, and obtains a second distortion evaluation index after statistical significance judgment. Performing instantaneous frequency stability analysis on the signal with significant distortion to obtain a second distortion evaluation index, and finally generating a corresponding waveform compensation parameter based on double indexes to realize real-time compensation correction; the integrity of the abnormal characteristic waveform in the transmission process is effectively maintained, and the accuracy and reliability of power consumption abnormity diagnosis are remarkably improved.

The invention discloses a new energy power system frequency supporting capability quantitative evaluation method and system based on frequency band analysis. Aiming at the frequency response difference of multiple types of power generation equipment in a new energy power system, a unified system frequency response model is established in a frequency domain, and the frequency supporting capability of the power generation equipment under different frequency bands is quantified by adopting a frequency band analysis method. Comprising the following steps: establishing a frequency response transfer function matrix based on a linearized dynamic equation of a multi-machine system; calculating a frequency band H2 / H infinity norm index in a selected frequency range to quantitatively characterize the stability performance of the system in inertia response and a primary frequency modulation stage; through normalization processing of the reference capacity and frequency of the system, comparison of frequency supporting capabilities of different devices and systems is realized. The response difference and contribution of the synchronous machine and the wind and light storage power electronic interface power supply in each frequency band can be accurately revealed, and a unified and effective frequency domain analysis method is provided for frequency modulation control design and frequency stability evaluation of a new energy power system.

The invention discloses a system reference clock frequency accuracy automatic calibration circuit and a calibration method thereof, and belongs to the technical field of frequency sources, the calibration circuit comprises a first crystal oscillator, a first power divider, a second power divider, a second crystal oscillator, an analog switch, a radio frequency switch, a detector, a comparator, an FPGA controller, a digital analog converter, an operational amplifier and a temperature sensor. When an external high-precision reference clock is accessed, the FPGA controller automatically switches a frequency measurement reference, performs high-precision frequency measurement on a 100MHz signal output by the first crystal oscillator, and judges whether calibration is needed or not according to frequency offset; if calibration is needed, the output voltage of the digital-to-analog converter is adjusted, the Vc end of the first crystal oscillator is controlled after operational amplification, and frequency closed-loop adjustment is achieved. According to the method, the crystal oscillator does not need to be disassembled, calibration is rapidly completed on site, and system availability and long-term frequency stability are remarkably improved.

The invention discloses a crystal oscillator taming system based on Kalman filtering and adaptive PID, and relates to the technical field of time-frequency equipment. Comprising a crystal oscillator time frequency module used for generating a local time frequency signal, a reference module used for receiving an external reference time frequency signal, an error measurement module used for measuring the phase deviation between the local time frequency signal and the reference time frequency signal, and a Kalman filtering estimation module used for performing Kalman filtering estimation based on the phase deviation. The Kalman filtering module is used for outputting phase deviation estimation and covariance estimation and adaptively adjusting PID parameters according to the phase deviation estimation, the position deviation estimation and the covariance estimation; the control feedback module is used for superposing the voltage-controlled voltage adjustment quantity to the crystal oscillator time frequency module to adjust the output frequency of the crystal oscillator; according to the method, the crystal oscillator taming parameters are dynamically adjusted through Kalman filtering in combination with self-adaptive PID, high-precision and robust taming of the crystal oscillator is achieved, and the long-term frequency stability and the time synchronization precision of the crystal oscillator are improved.

The invention provides a virtual inertia adaptive control method, device and system, and relates to the technical field of inverter system control. The method comprises the following steps: calculating a reference current value according to a power reference value and an actual output voltage; calculating a current deviation value according to the reference current value and the actual output current value; outputting the current deviation value to an adaptive resonance controller to obtain a compensation control voltage signal; inputting the compensation control signal to an AHO virtual oscillator to obtain a reference value of the output voltage of the inverter; and controlling the output of the three-phase inverter circuit according to the reference value of the inverter output voltage. Wherein the adaptive resonance controller carries out adaptive control through the proportional parameter and the proportional resonance inertial parameter. The virtual inertia output can be dynamically adjusted according to the real-time requirement of the system, the overshoot phenomenon caused by power oscillation is effectively suppressed while the frequency stability is met, and the capacity of the system for resisting sudden load change and frequency disturbance is enhanced.

The invention discloses a multi-type resource participation power grid frequency modulation method based on a consistency algorithm, and the method comprises the steps: firstly constructing an improved frequency response model fusing distributed optical storage equipment, hydrogen storage and energy storage equipment and a DC flexible load, identifying system parameters, solving a multi-resource comprehensive adjustment coefficient, constructing a directed graph model, employing a grouping consistency algorithm, and obtaining a multi-type resource participation power grid frequency modulation model; the optimal adjustment coefficient of each resource is solved through distributed optimization of an augmented Lagrange function and a consistency index, and primary frequency modulation of a multi-type resource collaborative response system is driven. According to the multi-type resource participation power grid frequency modulation method based on the consistency algorithm, by driving a multi-type resource collaborative response system to perform primary frequency modulation, collaborative regulation and control of light storage, hydrogen storage and flexible load are realized, economy and operation constraints are considered through distributed optimization, and communication complexity is reduced through a clustering iteration mechanism; and the frequency stability of the high-proportion new energy power grid is obviously improved.

The invention provides a passive laser gyroscope based on a light force induced transparency effect and a measurement method thereof, the passive laser gyroscope comprises a frequency stabilized laser light source, a signal modulation input device, a balance homodyne detection device, an annular optical resonant cavity and a signal detection and feedback device, wherein a reflection cavity mirror with a photomechanical resonance structure characteristic is integrated in the annular optical resonant cavity; according to the passive laser gyroscope, a narrow transparent window modulated by a mechanical damping rate is generated on an annular optical resonant cavity of the passive laser gyroscope by utilizing a light force induced transparency effect and a light-mechanical coupling effect, so that the quality factor of the annular optical resonant cavity is improved, and the measurement sensitivity of the passive laser gyroscope is enhanced.

The invention discloses a power system operation strategy generation method and device, equipment, a medium and a product, and belongs to the technical field of power system automation control. The method comprises the following steps: establishing a cooperative operation model of a wind turbine generator and a battery energy storage system participating in power grid primary frequency modulation; deriving an analytic expression of frequency stability constraints of the power system based on the collaborative operation model, wherein the frequency stability constraints comprise a maximum frequency change rate constraint, an overshoot constraint and a static frequency deviation constraint; constructing a wind power uncertainty model based on the uncertainty budget; constructing a mixed integer linear programming scheduling model taking the minimum total operation cost as a target; and solving the mixed integer linear programming scheduling model to obtain a power system operation strategy. According to the embodiment of the invention, the frequency safety level of the power system can be remarkably improved under the wind power uncertainty.

The invention discloses a beat frequency comparison device mediated by an optical frequency comb. The beat frequency comparison device comprises the optical frequency comb, a first frequency stabilized laser, a first beat frequency device, a first frequency mixer, a first high-pass filter, a second frequency stabilized laser, a second beat frequency device, a second frequency mixer, a second high-pass filter, a DDS signal generator, a third frequency mixer and a low-pass filter. Frequency-stabilized lasers output by the first frequency-stabilized laser and the second frequency-stabilized laser and an optical frequency comb output by the optical frequency comb are subjected to beat frequency in the first beat frequency device and the second beat frequency device respectively, and first beat frequency and second beat frequency are obtained; the first beat frequency and the second beat frequency are mixed with the carrier envelope offset frequency of the optical frequency comb, and a first sum frequency and a second sum frequency are filtered out; the first sum frequency obtains a synthetic frequency through direct digital frequency synthesis; the second sum frequency and the synthetic frequency are mixed in the third mixer, and then the difference frequency is filtered out through the low-pass filter. According to the invention, beat frequency comparison of frequency-stabilized lasers with different wavelengths can be realized, and the influence of the stability of the optical frequency comb is avoided.

The invention discloses a low-cost precise time keeping method, system and device based on a gating circulation unit, and relates to the technical field of power grid measurement. The method is executed when the synchronous phasor measurement device cannot receive external signals, and comprises the following steps: monitoring operation parameters which influence the frequency stability of an internal crystal oscillator of the phasor measurement unit in real time; calculating a current frequency error of the crystal oscillator in real time by using a crystal oscillator frequency drift prediction model based on a gated cycle unit network based on the operation parameters; generating a time correction amount according to the current frequency error; and applying the time correction to a local clock of the phasor measurement unit to compensate the frequency drift of the crystal oscillator so as to realize accurate time keeping. According to the invention, through accurate prediction of crystal oscillator errors and lightweight software compensation, the synchronous phasor measurement device adopting a low-cost crystal oscillator can also realize long-time high-precision time keeping, the hardware cost is obviously reduced, and the reliability of power grid monitoring during the Beidou / GPS lock losing period is improved.

The invention provides a laser frequency stabilization device and method based on optical frequency shift, and relates to the field of laser frequency stabilization, and the device comprises a first slave laser, a first frequency stabilization system, a second slave laser, a second frequency stabilization system, a master laser, an acousto-optic modulation module, and a phase-locked frequency stabilization device. The first slave laser is used for emitting first laser of a first wavelength; the main laser is used for emitting third laser with a second wavelength; the first frequency stabilization system is used for locking the first laser according to the first laser to obtain first frequency-stabilized laser; the second slave laser is used for emitting second laser with the first wavelength; the second frequency stabilization system is used for locking the second laser to obtain second frequency-stabilized laser; the acousto-optic modulation module is arranged between the first slave laser and a light path of the phase-locked frequency stabilization equipment; and the phase-locking frequency stabilization equipment is used for receiving the first frequency stabilized laser and the second frequency stabilized laser and carrying out frequency locking on the third laser according to the first frequency stabilized laser and the second frequency stabilized laser. According to the invention, the modulation transfer spectrum and the optical frequency shift can be combined to complete frequency locking of the laser.

The invention provides a gas saturation absorption optical path structure based on dual optical path enhancement, which belongs to the field of laser optical path design and comprises an optical fiber circulator, a gas absorption chamber and an optical fiber reflector. A first port of the optical fiber circulator is connected with a laser output optical fiber, a second port of the optical fiber circulator is connected with an input collimator of the gas absorption chamber, and a third port of the optical fiber circulator is connected with a detector and is used for providing frequency reference for gas absorption; and the optical fiber reflector is connected with the output end of the gas absorption chamber. According to the invention, the physical contradiction between the air chamber size and the optical path gain is broken through, and a compact frequency stabilization system with miniaturization and high stability is realized.

The invention discloses a new energy power station grid connection method and system based on Beidou satellite time service and synchronous compensation, and the method comprises the steps: receiving a Beidou satellite time service signal, generating unified reference synchronization time, and calculating a reference synchronization phase angle according to the reference synchronization time; taking the reference synchronous phase angle as a control reference, and driving a grid-forming inverter to execute grid-connected operation; the integrity index of the Beidou time service signal is monitored in real time, and when it is detected that the Beidou time service signal is abnormal or invalid, at least one stage of synchronous compensation mechanism is started according to the abnormal or invalid duration time and the system operation state so as to maintain the phase continuity and frequency stability of the grid-connected operation of the new energy power station.

The invention relates to the technical field of noise identification, in particular to a main sound source noise identification method and system for a flexible direct current converter station. Obtaining the current of the converter station and the audio time sequence data of each monitoring point; processing the audio time sequence data to obtain a time-frequency diagram, analyzing the amplitude change difference of different monitoring point positions under the same time-frequency point, adjusting the amplitude change condition of the time-frequency point of a target point position according to the amplitude change difference, obtaining an amplitude change index, and conveniently analyzing whether noise is from a converter transformer or not; for the magnetostrictive noise of the converter transformer core, the vibration frequency is stable, and the amplitude is synchronously changed along with the current, so that the correlation between the amplitude change index and the current time sequence data and the difference of the time sequence characteristics under each frequency are analyzed in the target point location time-frequency diagram, and the multi-frequency synchronization index is determined; the possibility that a frequency component is derived from an iron core magnetostriction effect is reflected; and finally, the amplitude change and the multi-frequency synchronization index are fused, the noise characteristics are integrated, and the noise source identification accuracy is improved.

The invention provides a Rydberg atomic electromagnetic signal detection device based on correlated photon coincidence measurement, and the device comprises a correlated photon source assembly which is used for enabling single-polarization and frequency-stable laser to generate polarization orthogonal correlated photon pairs; the Rydberg atom preparation system is in communication connection with the associated photon source assembly, and associated photon pairs emitted by the associated photon source assembly enter the Rydberg atom preparation system; the correlation detection assembly is in communication connection with the Rydberg atom preparation system and is used for counting transmission photons of the EIT-AT split transmission spectrum signals, and when the difference value between the reference photon arrival time and the transmission photon arrival time is within a preset range, the EIT-AT split transmission spectrum signals are regarded as coincidence events and coincidence counts are recorded. According to the invention, the problem of low sensitivity caused by the defects of optical readout noise, weak off-resonance field response, sensitive temperature drift vibration environment and the like in the prior art is solved.

The invention discloses an atomic frequency stabilization and optical phase cooperative locking Michelson laser displacement measurement system. The system comprises a Michelson laser displacement measurement module, an atomic frequency stabilization module and an optical phase locking module. The Michelson laser displacement measurement module comprises a reference sub-cavity, a measurement sub-cavity, a photoelectric detector and a data acquisition and analysis processing module; the cavity length of the reference sub-cavity is fixed, and reference laser with the output frequency is output; an output cavity mirror of the measurement sub-cavity is mounted on the object to be measured, and the cavity length of the output cavity mirror changes in real time along with the movement of the object to be measured, so that the frequency changes synchronously; the photoelectric detector is used for detecting beat frequency signals of the reference laser and the measurement laser; the data acquisition and analysis processing module is used for calculating the displacement of the to-be-measured object according to the beat frequency signal; and the optical phase locking module is used for synchronously locking the measuring laser and the reference laser. According to the invention, displacement measurement with sub-picometer resolution can be realized.

The invention belongs to the technical field of atmosphere detection remote sensing, and discloses an atmosphere multi-element integrated multi-wavelength coherent differential absorption laser radar system. Lambda on1 wavelength laser generated by the first frequency stabilization seed laser, lambda on2 wavelength laser generated by the second frequency stabilization seed laser and lambda off wavelength laser generated by the third frequency stabilization seed laser are transmitted to the switching module for time domain modulation to obtain an output signal, and the output signal is decomposed into local oscillation light and a main signal by the first coupler. A main signal is modulated by the pulse modulator, amplified by the amplification module and then transmitted to the optical transceiver module, backward scattered light scattered by the atmosphere is transmitted to the second coupler and is subjected to coherent coupling and equalization with local oscillation light, and coherent electric signals are transmitted to the data analysis module through the balance detector to be analyzed. The water vapor concentration, the wind speed and the atmospheric temperature in the propagation path are obtained. Through the coherent detection technology, the signal-to-noise ratio of signals is remarkably improved, and high-precision atmospheric humidity and wind field detection is achieved.

The invention discloses a wind turbine generator multi-stage self-adaptive droop control method considering rotor kinetic energy constraint and frequency change rate, which comprises the following steps: 1, constructing a rotation speed influence factor based on a Logistic function, mapping a rotor rotation speed into a frequency modulation contribution coefficient, and quantitatively evaluating a rotor kinetic energy releasable range of a fan under different operation conditions; 2, designing a self-adaptive droop control strategy based on a segmented frequency change rate, adjusting a droop coefficient in real time by identifying a frequency change rate interval, forming a hierarchical response mechanism, providing strong active support in a sharp frequency drop stage to quickly suppress frequency drop, and converting into moderate support in a frequency recovery stage to maintain stability and prevent secondary drop; and 3, building a wind-fire combined system simulation model, and verifying the effectiveness of the provided strategy in the aspects of improving the frequency response characteristic of the system and improving the frequency stability through a multi-scene contrast experiment. According to the method, the frequency regulation capability of the power system under the high wind power permeability can be remarkably enhanced.

In the field of ultrastable laser technology, tuning an ultrastable laser maintains its performance indicators without increasing additional lock noise and out-of-loop drift. [Solution] One acoustic-optic modulator and one electro-optic modulator are introduced separately, and the laser device, frequency shift unit, PDH frequency stabilization control unit, and ultra-stable cavity are integrated. [Effects] By changing the frequency of the acousto-optic modulator, high-precision tuning of the ultra-stable laser can be achieved. By changing the frequency of the electro-optic modulator, wide-range tuning of the ultra-stable laser can be achieved, enabling wide-range, high-precision, and dead-zone-free frequency tuning.

This invention relates to the field of laser technology, specifically to a three-optical-path integrated PDH frequency stabilization system. It includes a three-laser input module, an integrated optical module, and three independent servo control modules. The three-laser input module provides three laser beams to be stabilized. The integrated optical module integrates the functions of the three independent optical paths onto a single substrate, achieving separation of transmission, beam combining, and reflected light. Simultaneously, it receives the three reflected beams and converts them into three electrical PDH error signals. The three independent servo control modules receive the three error signals respectively, process them, and generate feedback control signals, which are fed back to the corresponding three lasers to complete three independent frequency-locking loops. This invention significantly reduces the system's size and cost. The integrated optical module achieves compact integration of the three optical paths, improving system stability and anti-interference capabilities, reducing debugging difficulty, and ensuring system consistency.

The invention relates to the technical field of electromagnetic compatibility (EMC) design of electronic circuits, in particular to a method suitable for a flow cytometer and capable of reducing interference of clock signals on EMC. The method comprises the steps that S100, clock circuit components are concentrated in a 5mm * 5mm area of the top layer of a PCB, routing is limited to a second layer through buried holes, and fundamental frequency is dynamically set; s200, laying copper in a key area for grounding, and adding a ground bounce suppression array to three layers; s300, arranging an upper ground copper layer and a lower ground copper layer by using a flexible circuit board; s400, covering the top circuit with a ferrite alloy cover, and welding and grounding; and S500, the flow velocity and the cell density are collected in real time, the clock frequency is dynamically adjusted, a frequency stabilization mechanism exists in an extreme scene, radiation is effectively reduced, and the detection precision and stability are improved. According to the method, the EMC interference of the clock signal of the flow cytometer is reduced from multiple dimensions of source inhibition, shielding protection, connection optimization and cooperative control.

The invention belongs to the technical field of power system control, and particularly relates to a multi-area power system control method and system based on elastic event triggering, and the method comprises the steps: firstly building a unified linearization model of a multi-area power system; then, a state observer and a dynamic memory event triggering mechanism are set for each control area, and the mechanism dynamically decides a communication sending moment based on a weighting function of current and historical state estimation errors so as to greatly reduce redundant data transmission; and furthermore, based on a state estimation value output by the observer and neighborhood information subjected to event triggering scheduling, a distributed feedback control law is constructed, and a control input signal of each region is calculated and generated through a preset control gain matrix. According to the method, the communication load is remarkably reduced, meanwhile, it is ensured that the frequency of the multi-region power system can be kept stable when the multi-region power system is attacked by the bounded network, and the operation efficiency and safety of the system are effectively improved.

The present application relates to laser frequency stabilization technology, in order to solve the contradiction between chip and long-term frequency stability of on-chip frequency stabilization technology, provide a kind of long time laser frequency stabilization system based on on-chip optical reference microcavity, including: two lasers, on-chip optical reference microcavity;Two frequency locking modules are used for locking two lasers to two different modes of on-chip optical reference microcavity respectively;Dual-mode beat frequency measurement and control module is used for real-time measurement of the dual-mode frequency difference between the two different modes locked to on-chip optical reference microcavity;In-cavity temperature slow feedback control loop is used for generating temperature fine control feedback signal based on dual-mode frequency difference, and the fine temperature of on-chip optical reference microcavity is adjusted according to temperature fine control feedback signal, to compensate the optical cavity length change caused by thermo-optic effect and thermal expansion effect, so as to stabilize the resonant frequency of on-chip optical reference microcavity, reduce the long-term drift of on-chip laser light frequency, improve the long time frequency stability of laser single frequency output.

The invention discloses a distributed architecture voltage frequency control method and a distributed architecture voltage frequency control system for a DRU-sent network construction energy storage new energy island. The island comprises a plurality of new energy stations, matched new energy storage stations and a DRU alternating current side energy storage station. Aiming at DRU side energy storage, on the basis of keeping active-frequency droop control, a reactive-voltage droop loop is replaced by a DC power-voltage control loop, and the DRU is controlled to send a power tracking scheduling instruction by adjusting an output voltage; for new energy side energy storage, active-frequency droop and reactive-voltage droop are adopted to construct a local voltage frequency, an active power compensation instruction distributed by a system-level constant-frequency control loop is received, a local active reference value is corrected, and system frequency indifference adjustment is realized. The method adapts to the specific power-voltage coupling characteristic of the DRU, the frequency can be kept stable when the new energy output fluctuates, the power is constantly sent out according to the scheduling instruction, and the operation reliability and schedulability of the island system are improved.

The utility model provides a high-temperature-resistant sinusoidal signal source filter circuit, which comprises a high-stability oscillation source module, the high-stability oscillation source module is composed of a crystal oscillator Y1 and other elements, the frequency stability of an oscillation source is ensured, the output frequency of a sinusoidal signal source can be changed by changing the frequency of the crystal oscillator, an inverter U1B shapes and outputs oscillation source signals, and the signal quality is further ensured. The power supply filtering module effectively eliminates circuit noise and interference, the high-stability voltage source module supplies power to the oscillation source circuit through a resistor R1, a voltage stabilizing diode D1 and a capacitor C5, the temperature stability of the oscillation source circuit is good due to the characteristics of the voltage stabilizing diode D1, and it is guaranteed that the circuit works stably under different conditions. The signal amplitude adjusting module can flexibly change the output amplitude of the sinusoidal signal source, the active band-pass filtering module can accurately convert square wave signals output by the oscillation source into sine wave signals, parameter setting is reasonable, and the characteristics of quality factor Q, gain G, center frequency F and the like enable the signal processing effect to be good. And parameters of the band-pass filter are matched with parameters of the oscillating source during debugging, so that the circuit is stable and reliable in overall performance, and is suitable for high-temperature environments and other scenes with high signal quality requirements.

This invention discloses a high signal-to-noise ratio modulation transfer frequency stabilization optical path device, including a light source and a frequency stabilization optical path. The light source adopts an internally adjustable fiber collimator, with a 45° reflector behind it. The frequency stabilization optical path behind the 45° reflector includes a half-wave plate and a polarizing beam splitter (PBS). An atomic gas cell and two pyramidal reflectors are sequentially arranged on the probe light path of the PBS. A half-wave plate, a 45° reflector, an electro-optic modulator, another 45° reflector, and a half-wave plate are sequentially arranged on the pump light path. The polarizing beam splitter (PBS) is located at the convergence point of the two optical paths, and a 45° reflector, a frequency stabilization optical path lens, and a photodetector are sequentially arranged behind it. This invention cleverly utilizes a folded optical path design and fine-tunes the beam divergence angle to increase the length and area of ​​the laser-atomic interaction without increasing the system volume. At the same time, it actively controls the splitting ratio of the two frequency-stabilized beams, improving the stability of the frequency stabilization.

This improves the degradation of the cross-correlation coefficient caused by the error between the set frequency and the actual frequency of the light source, and makes it possible to improve the degradation of the measurement accuracy of strain and temperature. [Solution] The light source unit has a frequency-stabilized wavelength-tunable laser that generates continuous light, and a first optical coupler splits the continuous light generated by the light source unit into two, sending one to a second optical coupler and the other to an optical frequency measurement unit. The optical frequency measurement unit measures the frequency of the continuous light generated by the light source unit, and the second optical coupler further splits the continuous light split by the first optical coupler into two, sending one as probe light to the optical pulse generation unit and the other as local light to a detection unit. The detection unit measures the frequency change Δf by means of coherent time domain reflectometry and a means for heterodyne detection of the Rayleigh scattered light and the local light resulting from Rayleigh scattering of pulsed light in the fiber under test. max and means for acquiring the

The application relates to a high-precision single-frequency laser seed injection locking method, steps S1, a resonant pulse signal is generated based on an FPGA unit and a piezoelectric ceramic, the resonant pulse signal collected by an ADC unit is monitored, and the time t1 required from the start of a slope voltage to the appearance of an error signal is recorded; steps S2, after the error signal is monitored, the slope voltage is slowly adjusted, the S-shaped waveform center position of a resonant cavity spectrum range corresponding to a plurality of resonant pulse signals is detected based on a peak value detection module, a PID feedback control program is started, and the time t2 is recorded; steps S3, after the error signal is stabilized at the S-shaped waveform center 0 point position, the time t3 is kept, the Q switch signal is turned on while the PID feedback control is turned off, the Q switch signal is kept for the time t4 and then turned off, and the digital quantity corresponding to the slope voltage at the moment is recorded; and steps S4, the slope voltage is controlled to drop to 0V, a period of time is kept, and the overall time of the step S4 is recorded as t5. The application has the characteristics of adjustable repetition frequency, high time stability and high frequency stability.