292 results about "Heterodyne" patented technology

The invention relates to the technical field of laser ranging, in particular to a double-optical-comb hybrid ranging device which comprises a signal detection optical path system and a signal demodulation optical path system. Wherein the signal detection optical path system comprises a first optical frequency comb, a first optical isolator, a first optical collimator, a first beam splitter prism, a reference mirror, a Faraday rotator, a convergence mirror and a target reflector; the signal demodulation optical path system comprises a second optical frequency comb, a second optical isolator, a second optical collimator, a half-wave plate, a second beam splitter prism, a third beam splitter prism, a first polarization controller, a first photoelectric detector, a reflector, a polarization beam splitter prism, a second polarization controller and a second photoelectric detector. A third polarization controller; and a third photoelectric detector. According to the invention, three ranging technologies of asynchronous optical sampling ranging, multi-heterodyne interference ranging and synthetic wavelength ranging are fused, and the problem that a large ranging range and high ranging precision cannot be simultaneously considered in the ranging process is solved.

The invention belongs to the technical field of computer vision and optical measurement, and discloses a three-dimensional reconstruction method and device based on multi-frequency fringe synchronous optimization and a medium, and the method comprises the following steps: based on a monocular structured light system, projecting a plurality of groups of sine fringe images with different frequencies to the surface of an object to be measured through a projector, and carrying out the stepping of a plurality of phases, acquiring a corresponding image sequence by using a camera; using a structured light phase shift method to obtain a relative phase value of a pixel point; obtaining an initial absolute phase value and modulation intensity based on a structured light phase shift method and a multi-frequency heterodyne method; and carrying out joint optimization on the absolute phase and modulation intensity parameters of the multi-frequency fringes through a Gaussian-Newton iteration method. According to the method, the anti-noise capability and the reconstruction precision are improved, a parameter adjustment and threshold recovery mechanism is introduced in the optimization process, the convergence stability and abnormal value elimination are ensured, and the method is suitable for high-precision structured light application scenes such as industrial vision measurement and complex surface detection.

The invention provides a non-power-cut test method for mutual inductance parameters of a power transmission line under excitation of different-frequency signals and a related device, and solves the problems of difficulty in accompanying stop and high safety risk of adjacent lines. The method comprises the following steps: selecting one circuit in the same corridor for power failure, connecting the head end with an induced electricity suppression device, and performing three-phase short-circuit grounding at the tail end; injecting a different-frequency sinusoidal current of 45-55Hz into the power failure line; the synchronous measurement device collects head and tail voltage and current of a running line based on a satellite synchronous clock; extracting pilot frequency signals through two-stage notch filtering and Fourier transform; and different-frequency zero-sequence self-impedance and mutual impedance are calculated and converted into power-frequency impedance. According to the invention, accurate test without power failure can be realized, and safety and power supply reliability are guaranteed.

The invention discloses a cultural relic restoration decision-making method and system based on computer three-dimensional modeling, and relates to the technical field of cultural relic restoration, and the method comprises the following steps: building a unified time baseline, generating a phase reference field, introducing a double-frequency comb interference structure to reconstruct a humidity refraction field, locking a zero-phase anchor point, and forming an initial constraint condition of a scanning path; under an initial constraint condition, an airflow phase gradient is obtained by adopting a Schlenn pilot frequency chromatography method, a nonlinear diffraction nucleus is calculated, and a refraction residual spectrum is output for modeling correction. According to the method, humidity disturbance is recognized through interference measurement and chromatography, real-time compensation is achieved in combination with phase sheath and humidity control, the crack and material characteristics are fused through neural field modeling, the solidification process is played back in combination with a mineralization mechanism, and the three-dimensional modeling precision and the restoration decision scientificity are improved.

The invention relates to the technical field of optical imaging, and discloses a single-pixel color imaging system based on multi-wavelength radio frequency marking. The system comprises a light source module used for generating three laser beams with three optical primary colors; the radio frequency driving module is used for generating a radio frequency complex frequency signal; the light path adjusting module is used for performing heterodyne interference processing on the three laser beams according to the radio frequency complex frequency signal, respectively forming a light spot array and a reference light source and then combining the beams, and generating a combined beam to be incident on a measured target; each laser beam corresponds to one group of sub light spot arrays; sub light spot arrays with aligned spatial positions exist among the three groups of sub light spot arrays; the detected target detection module is used for collecting light data generated after a detected target reflects the combined light beam; and the image inversion module is used for performing image inversion processing on the optical data to generate a true color image of the measured target. According to the system, the light spot array of multi-wavelength laser incidence can be registered in the spatial position.

A zero-optical-path-difference double-frequency heterodyne grating ruler comprises a light source, a signal detecting and processing system, a polarization splitting prism, a first quarter-wave plate, a rectangular prism, a second quarter-wave plate, a third quarter-wave plate, a total reflection mirror, a long-strip prism, a reference grating and a 45-degree-placed polaroid. The two measuring light paths of the system always keep zero optical path difference, so that the measuring precision can be ensured, and the environmental stability of the system is also remarkably improved. And a high-precision and high-robustness measurement scheme is provided for precision equipment such as a photoetching machine and a precision motion platform.

The invention discloses an uninterrupted calibration method and device for a medium and low voltage current transformer and a medium. The method comprises the following steps: measuring a primary side original current signal of a to-be-measured current transformer by using a pre-prepared mobile calibration platform; injecting a reverse current with the same frequency as the injection current source of the current transformer to be detected into the current transformer to be detected, and counteracting a primary side original current signal of the current transformer to be detected; generating a pilot frequency current according to a pre-selected pilot frequency signal by using an injection current source, inputting the pilot frequency current to a primary side of the current transformer to be detected for pilot frequency current calibration, and collecting a secondary side output signal; performing error analysis on the to-be-detected current transformer based on the secondary side output signal, and determining an error analysis result; and adjusting the calibration parameters of the to-be-detected current transformer based on the error analysis result to perform pilot frequency current calibration again until the error analysis result meets a preset requirement, and completing calibration of the to-be-detected current transformer.

The invention discloses a planetary atmospheric trace gas spectrum telemetering and in-situ fusion detection system and method, and belongs to the technical field of deep space exploration. The detection system has a telemetering mode and an in-situ detection mode, and comprises a telescope module, a laser light source module, a heterodyne spectrum telemetering module, an in-situ absorption spectrum module, a gas sampling and enriching module and a signal acquisition, processing and control module. In the on-orbit stage, a heterodyne spectrum telemetering module is adopted, and a laser light source and sunlight signals are subjected to frequency mixing for atmospheric component telemetering; and after the detector enters an atmospheric descending section, the in-situ absorption spectrum module performs in-situ absorption spectrum measurement by utilizing the detection light of the same laser light source. By performing space-time fusion and joint inversion on the data acquired in the two modes, coherent detection from large-range general survey to fixed-point detailed survey is realized, the problems of load separation of telemetering and in-situ detection and difficulty in data fusion are solved, and the detection efficiency, the data consistency and the integration level of the system are greatly improved.

The invention discloses an SERF atomic gyro signal detection device and method based on an optical heterodyne method, and belongs to the technical field of atomic polarization stability control, after magnetic fields with x-axis frequency and y-axis frequency are applied to atoms in a sensitive unit air chamber, x-axis electron polarizability information under respective modulation frequencies comprises longitudinal polarizability information and longitudinal magnetic field information, and x-axis electron polarizability information and y-axis electron polarizability information under respective modulation frequencies comprise longitudinal polarizability information and longitudinal magnetic field information; the value of the longitudinal polarizability is obtained by resolving information contained in the two, and effective longitudinal polarizability closed-loop control is achieved through a liquid crystal phase delayer power stabilizing rate system. Based on the biaxial magnetic field modulation technology, interference of longitudinal magnetic field fluctuation on polarizability closed-loop control is effectively avoided, and effective polarizability in-situ closed-loop control is achieved.

The invention discloses a distributed optical fiber two-dimensional vector sensing system and method, the system uses an acousto-optic modulator group and an optical circulator group to ask a plurality of fiber cores of a multi-core optical fiber in parallel, heterodyne coherent detection uses local oscillator light to improve the signal-to-noise ratio, and through the relation between the fiber core position difference and the direction angle of a two-dimensional sound wave in the aspect of algorithm, the two-dimensional sound wave direction angle is obtained. According to the space division multiplexing distributed optical fiber acoustic sensing system, a two-dimensional vector signal is accurately restored, the measurement vector angle range of the space division multiplexing distributed optical fiber acoustic sensing system for two-dimensional sound waves is 0-360 degrees, the vector sensing range is larger than 50 km and far exceeds that of an existing system, and the detection capacity of the distributed optical fiber acoustic sensing system is greatly improved.

The invention relates to a Rydberg atomic communication receiving system and method based on AT split peak value analysis, and belongs to the technical field of quantum communication. The system comprises a detection laser, a coupling laser, an AOM / EOM, a function generator, a high-frequency signal generator, a cesium atom gas chamber, a photoelectric detector, a lock-in amplifier, a data acquisition module and a microwave signal output module. The AOM / EOM modulates the frequency of the detection laser; the microwave signal output module generates an AM modulation microwave signal and transmits the AM modulation microwave signal to the cesium atom gas chamber, so that the target Rydberg state atoms generate an AT splitting effect to calibrate system parameters; the photoelectric detector and the lock-in amplifier obtain a first harmonic component based on the transmission light. During communication, the system is arranged in a microwave electric field received by communication, and the data acquisition and processing module outputs AM modulation microwave signals received by the recovered cesium atom gas chamber based on calibrated system parameters and phase locking. The method solves the problem of signal distortion existing in EIT-AT direct communication transmission and the problem of tedious operation of a heterodyne method.

The invention relates to a fringe projection high-reflection surface phase unwrapping method based on frequency reuse. The fringe projection high-reflection surface phase unwrapping method comprises the steps of collecting a multi-frequency fringe image and dividing the multi-frequency fringe image into an overexposure area and a non-overexposure area, solving a wrapped phase in the non-overexposure area by adopting a generalized phase shift method, obtaining an initial unwrapping phase based on a multi-frequency heterodyne algorithm, and performing block filtering and interpolation processing to obtain a fringe projection high-reflection surface phase unwrapping phase. A continuous unwrapped phase containing a high-reflection area is obtained, a complementary Gray code consistent with a wrapped phase period is constructed in combination with a multi-threshold constraint and is used for correcting the stripe level of an overexposure area, brightness attenuation design is further carried out on low and medium frequency stripes, frequency reuse is achieved, and the high-reflection area is obtained. Obtaining an unwrapped phase of an overexposure point in a non-high-frequency stripe and mapping the unwrapped phase to a high frequency; the method comprises the following steps of: extracting and fusing a wrapped phase by adopting one-dimensional Fourier and Hilbert transform for areas with overexposure of each frequency, and selecting and inhibiting spectrum leakage through a complete period, so that effective correction of the wrapped phase and stripe level of an overexposure point is realized, and a reliable unwrapped phase is obtained.

The invention discloses a laser Doppler heterodyne noninvasive blood glucose concentration measuring device and method, and belongs to the technical field of medical detection. Comprising a laser generating module which comprises a laser, and a first 1 / 2 wave plate and a polarization splitting prism which are sequentially connected with the laser; and the interference light path module is connected to the two sides of the polarization splitting prism respectively and comprises a first optical fiber coupler connected with the polarization splitting prism, and a second 1 / 2 wave plate and a second optical fiber coupler which are sequentially connected with the other side of the polarization splitting prism. The device has the advantages that noninvasive detection can be achieved, blood sampling wounds are avoided, and the comfort level of a patient is improved; the measurement precision is high, and the blood glucose value can be quickly and accurately obtained by using heterodyne interference and frequency shift technologies.

In a general aspect, a magnetic resonance system performs magnetic resonance measurements. In some examples, a magnetic resonance system includes a data processing device and a superheterodyne spectrometer system. The data processing device generates digital intermediate frequency (IF) signal information based on the pulse profile. The digital IF signal information is configured to suppress a mirror sideband in the magnetic resonance control signal. The superheterodyne spectrometer generates a magnetic resonance control signal based on the digital IF signal information.

The invention provides a double-circuit line mutual inductance online monitoring system based on a distributed sensor. The system comprises a distributed intelligent sensing node cluster module, a data processing module, an energy and communication module, a dynamic pilot frequency excitation control module and a mutual inductance parameter monitoring module. The distributed intelligent sensing node cluster module deploys one intelligent sensing node every 500 meters along the double-circuit line and is used for collecting mechanical data, environmental data and pilot frequency excitation response data of the double-circuit line in real time; the data processing module is used for receiving the original data transmitted by the distributed intelligent sensing node cluster module and preprocessing the original data; the energy and communication module is used for providing a power supply and a data transmission channel for each module; the dynamic pilot frequency excitation control module is used for dynamically adjusting a pilot frequency excitation signal according to the power frequency interference intensity; and the mutual inductance parameter monitoring module is used for constructing a line electromagnetic-mechanical coupling simulation model and calculating mutual inductance parameters of the double-circuit line.

The invention discloses a device for generating Mach-Zehnder interference, a photo-thermal spectrum gas sensing device based on the device and a detection method, and belongs to the technical field of laser spectrum gas sensing. The interference device sequentially comprises an optical frequency comb and a first light beam splitter on a light transmission path; a movable arm reflector group is arranged on the light path of one light beam B in the two light beams split by the first light beam splitter, the path of the light beam B is changed through the movable arm reflector group, the light beam B intersects with the light path of the other light beam C, and a beam combiner is arranged at the intersection; the movable arm reflector group is connected with a driving mechanism, the driving mechanism is used for driving the movable arm reflector group to do linear motion, and the track of the linear motion is parallel to the straight line where the light beam B is located. The interference device does not need to use a local oscillator optical comb and a signal optical comb to carry out multi-heterodyne interference, can directly use the moving speed of a movable arm reflector group in a Mach-Zehnder interference structure to calculate a down-conversion factor, and maps each longitudinal mode of the signal optical comb in an optical frequency to a radio frequency component one by one.

The invention discloses a distributed sound wave sensing device based on PDH frequency locking and a demodulation method. The distributed sound wave sensing device comprises a narrow linewidth laser, a first optical fiber coupler, a heterodyne phase sensitive optical time domain reflectometer and a frequency stabilization feedback module. The frequency stabilization feedback module comprises a frequency stabilization modulation and demodulation module, a reference cavity and a server; the frequency stabilization modulation and demodulation module comprises an electro-optical modulator or an acousto-optical modulator, a photoelectric detector, a multiplier and a low-pass filter; the first path of light enters a reference cavity for resonance after being modulated by an electro-optical modulator or an acousto-optical modulator, a resonance signal enters a photoelectric detector through cavity reflection, and a signal output by the photoelectric detector is subjected to signal demodulation by a multiplier and a low-pass filter and then is used as feedback to be input into a server for proportional-integral processing; the laser is fed back and output to a modulation interface of the narrow-linewidth laser, and frequency compensation is performed on the laser, so that the laser is locked on the reference cavity; according to the invention, through frequency stabilization and homologous modulation and demodulation, line width and phase drift of the laser can be suppressed at the same time.

The invention discloses a multidimensional communication sensing system integrating an optical transmission network and BOTDR / DAS distributed sensing, and relates to the technical field of optical fiber communication and optical fiber sensing. The system comprises an OTN transmission subsystem, an optical fiber link and a BOTDR / DAS fusion sensing subsystem. Wherein the OTN transmission subsystem is used for realizing high-capacity data transmission through an optical fiber link; and the BOTDR / DAS fusion sensing subsystem is used for realizing strain, temperature and vibration distributed measurement of an optical fiber link through a Brillouin scattering and Rayleigh backscattering mechanism. According to the system, a double-self-heterodyne demodulation architecture and a reverse wavelength division multiplexing mechanism are adopted, cooperative demodulation and high-isolation transmission of BOTDR and DAS signals are achieved under the common-fiber condition, and high-speed communication and distributed temperature, strain and vibration synchronous monitoring within the 100 km range can be achieved. According to the method, a technical foundation can be laid for realizing physical layer intelligentization of the in-service power OTN.

The invention relates to a reduced-size FMCW lidar imager system. The imager system comprises an optical source 10 for a coherent, continuous and frequency-modulated primary signal Sp in order to illuminate the scene 2; an optical collection element 41 configured to collect a backscattered signal Sret,c; a photodetector 50 intended to receive a heterodyne signal Sh associated with the collected signal Sret,c; and a processing unit 60 configured to determine the distance zsc from the scene based on a beat frequency of the heterodyne signal sh. It is configured to fully direct the primary signal Sp to the scene 2. It additionally comprises a reflector 42 configured to reflect a portion Spr,nc, called uncollected signal Sret,nc, of the backscattered signal Sret, not collected by the optical collection element 41, in the direction of the scene 2.

The invention discloses an aircraft composite material structure health monitoring system and method, and relates to the field of aircraft material health monitoring, and the system comprises a DAS integrated optical module which is used for generating and transmitting an optical pulse pair subjected to heterodyne phase modulation to a single-mode optical fiber sensing network, and converting backward Rayleigh scattering light into an electric signal; the single-mode optical fiber sensing network is arranged on the surface of the aircraft composite material structure and is used for converting an acoustic emission signal containing the physical change of the aircraft composite material structure into an optical phase change signal by utilizing a coherent Rayleigh scattering effect; the digital signal processing module is used for carrying out signal processing on the electric signal by utilizing a heterodyne phase modulation method based on instantaneous frequency tracking so as to identify and position the damage of the aircraft composite material structure; and the alarm output module is used for outputting a damage position, a damage degree grade and an alarm signal of the airplane composite material structure in real time when the structural damage is detected, so that full-distribution and wide-range online accurate monitoring is realized.

The application discloses a kind of resonance quartz enhanced dual optical comb photoacoustic spectroscopy gas detection devices, device includes dual optical comb source, acoustooptic frequency shift component, quartz resonant component, signal amplification component, phase-sensitive demodulation component and normalization component;Dual optical comb source is as the excitation light source of photoacoustic effect, it realizes real-time frequency shift by acoustooptic frequency shift component;Dual optical comb source is emitted by acoustooptic frequency shift component and after acting on gas molecule, produces multi-heterodyne sound wave, and quartz resonant component extracts resonance component therein and converts it into electrical signal;The electrical signal generated is successively processed by signal amplification component, phase-sensitive demodulation component, normalization component, and the composition discrimination of target gas and concentration inversion are realized by signal after processing.This application improves the structure and detection mode of dual optical comb photoacoustic spectroscopy, completes the resonance detection of dual optical comb photoacoustic spectroscopy, improves the detection sensitivity of system by acoustic and electrical two-stage filtering, and increases the dynamic range of system.

The application relates to the technical field of laser speed measurement, and discloses a laser Doppler speed measurement system and a speed measurement method. The system comprises a dual-frequency laser device, a first detection beam splitter, a second detection beam splitter, a first detection device, a second detection device and a signal processing device. The dual-frequency laser device is optically connected with the first detection beam splitter and the second detection beam splitter. The first detection beam splitter and the second detection beam splitter are respectively optically connected with the first detection device and the second detection device. The first detection device and the second detection device are optically connected with the signal processing device. The application constructs a set of optical path "cross pairing" dual-channel differential heterodyne interference systems, so that the interference optical path of each detection device simultaneously contains frequency components from two lasers. The inherent output frequencies of the two detection devices are equal in size and opposite in sign, have common mode rejection characteristics, effectively reduce the dependence of the system on the long-term stability of the core frequency shift device, and improve the measurement accuracy and reliability.

A line monitoring system can include a laser source to emit a probe signal over a first bandwidth; a polarization preserving tap to receive the probe signal and split the probe signal into a first portion and a second portion; a polarization rotator to receive the first portion and send the first portion to a transmission system; a loop tap to receive the second portion and receive a loop signal from the transmission system, wherein the loop signal is derived from the first portion; a photodetector coupled to receive an interference signal from the loop tap, wherein the interference signal is generated by mixing the loop signal with the second portion, wherein the photodetector is arranged to output a power signal based on the interference signal; and a power measurement system to measure the power signal over a second bandwidth comparable to the first bandwidth at a given measurement frequency.

The application discloses a permanent magnet synchronous motor position estimation method based on secondary harmonic tracking. When the permanent magnet synchronous motor is in zero speed and low speed state, a high-frequency sinusoidal pulse voltage signal is injected into the estimated d-axis of the motor. The secondary harmonic current response signal is extracted, and the amplitude thereof is obtained through heterodyne and low-pass filtering processing. The system is converged to the minimum point of the current secondary harmonic amplitude through the minimum value gradient tracking method, so that the effective detection of the zero speed and low speed position of the permanent magnet synchronous motor is realized. The application can realize the unique position convergence point in the whole error range, so as to improve the estimation performance and robustness of the system in the zero speed and low speed interval.

The invention discloses a compact double-frequency heterodyne triaxial grating ruler, and belongs to the technical field of precision optical measurement. The grating ruler adopts an integrated compact structure formed by stacking a double-frequency cross-polarization laser light source, a prism and detector module, a beam combining prism module and a two-dimensional reflecting grating from top to bottom. The method is characterized in that measurement light is made to deviate from the center of a beam combining prism in a beam combining prism module for normal incidence, the geometrical configuration of the beam combining prism is combined, and multi-stage diffraction light beams generated after the measurement light is irradiated to a two-dimensional reflection grating are spatially separated in the prism; and two beam combining gratings with orthogonal scribed line directions are utilized to carry out common-path beam combination on + / -1 level diffraction beams representing X and Y axial displacements to form X, Y and Z three-axis measurement beams which are independent from each other on a spatial light path. And finally, photoelectric conversion and signal processing are carried out through a prism and a detector module, and the three-degree-of-freedom displacement is calculated synchronously. The device effectively inhibits inter-axis crosstalk, has the advantages of being compact in structure, easy and convenient to install and adjust and high in environment interference resistance, and is suitable for the ultra-precision measurement field of photoetching machines, precision motion platforms and the like.

A method, wherein an optical input signal is received. The optical input signal includes an optical signal power and an input optical spectrum. The optical input signal is split into a first optical replica of the optical input signal and a second optical replica of the optical input signal. The first optical replica of the optical input signal is transmitted through a fiber laser cavity. A portion of the at least one lasing mode is transmitted from the fiber laser cavity to an optical heterodyne receiver, and the second optical replica of the optical input signal is transmitted to the optical heterodyne receiver. An electrical output signal including an output electrical spectrum is generated. The output electrical spectrum includes a compressed replica of the input optical spectrum. A measurement of the input optical spectrum is determined based on a respective Brillouin frequency shift and at least one input frequency.

A method and system for measuring physical parameters using sensors of the birefringent Fiber Bragg Grating type is provided. In some embodiments, a method and a system for querying a sensor of the birefringent Fiber Bragg Grating (FBG) type (e.g., in birefringent fiber), employing heterodyne optical detection and integrated photonic technology is provided.

The invention relates to a random number sequence generator comprising measuring means for measuring a plurality of continuous observables of an electromagnetic field, digital conversion means operatively connected with the measuring means for obtaining the measurement of each observable of the plurality of random number sequences, characterized in that the measuring means comprise one or more differential photodetection blocks followed by electronic homodyne (EO) or electronic heterodyne (EE) type blocks, possibly in parallel, with single- frequency or multi-frequency optical / electrical local oscillators, followed by analog / digital converters and by a subsequent digital filtering.

The application discloses a kind of bandwidth saving coherent transmission method and PON system, it is related to optical access network technical field, including: in downlink transmission direction, OLT sending end generates M digital subcarriers, after digital-analog conversion, it is carried out double polarization modulation, as downlink signal is sent to ONU receiving end;Each subarea ONU receiving end carries out heterodyne coherent detection to the partial spectrum of downlink signal, and downlink signal occupies the single sideband spectrum of ONU end light source;In the direction of uplink transmission, the data of corresponding digital subcarrier is generated by ONU sending end, and single sideband modulation is carried out based on ONU end light source, as uplink signal is sent to the OLT receiving end of corresponding subarea, and uplink signal occupies another single sideband spectrum of ONU end light source;OLT receiving end carries out analog-digital conversion and digital signal processing after heterodyne coherent detection.The application selects subcarrier by configuring light source of different wavelength at ONU end to reduce device bandwidth, so that PON system reduces cost while maintaining transmission capacity, sensitivity and flexibility.

This invention provides an acoustic wave sensing system based on master-slave laser phase-locked loop (PLL). A frequency-locking unit locks the frequency difference between the master and slave lasers to a highly stable reference frequency source, thus separating the acoustic wave signal from the background noise. The slave laser is then exposed to the acoustic field under test, and its output light frequency and phase are modulated accordingly by acoustic wave disturbances. The master and slave lasers generate a heterodyne beat frequency optical signal via a beam combining unit. A phase comparison unit compares this beat frequency electrical signal with a reference radio frequency signal to generate an error signal proportional to the instantaneous phase difference. A servo control unit conditions and amplifies the error signal, driving a tuning unit to adjust the output frequency and phase of the slave laser in real time, forming a negative feedback closed loop. The adaptive compensation characteristics of the closed-loop control give the system a strong ability to suppress slowly varying interferences such as environmental temperature changes and mechanical vibrations.