300 results about "Optical comb" patented technology

The invention provides a frequency-modulated continuous wave laser ranging device based on frequency shift double optical combs, which integrates frequency-modulated continuous wave and double optical comb technologies and comprises an FMCW light source, a beam splitter, a detection and reference light channel, a beam combiner, a photoelectric detector and a processing module. The FMCW light source outputs linear frequency sweeping laser which is divided into two paths through the beam splitter, and the detection light channel detects a target through the first optical comb generator and the circulator. The frequency fFS of the reference optical channel is increased through a frequency shifter, optical combs with different comb tooth intervals are generated by a second optical comb generator, and the fFS and the repetition frequency difference delta fR are in a non-integer multiple relation, so that interference is effectively avoided. After being combined by the beam combiner, the two paths of signals are converted into beat frequency signals by the photoelectric detector, and then time domain signals are spliced by the processing module by using coherence, so that the distance measurement precision is improved. According to the invention, the frequency shift double-optical comb technology improves the precision and anti-interference performance; an efficient data processing algorithm ensures rapid measurement and a wide range of application.

The invention discloses an ultra-low phase noise microwave signal generation method and system based on an electro-optical comb. The method comprises the following steps: 1) locking two lasers with continuously tunable wavelengths in the same FP cavity through two links with different modulation frequencies to realize a dual-wavelength laser with a frequency interval of (v2-v1); 2) reducing the electronic noise of each link to a quantum noise limit by using a residual amplitude modulation noise control technology; 3) coupling the lasers with the center frequencies of v1 and v2 into one path, inputting the laser into an electro-optical frequency comb generator, and generating two sets of electro-optical frequency combs with spectrum overlapping; (4) beat frequency signals of the two electro-optical frequency combs are obtained; the beat frequency signal and a reference signal from a reference signal source are accessed to a phase discriminator for phase discrimination; an output signal of the phase discriminator is sent to a proportional-integral-differential control circuit; and 5) controlling the phase noise of the radio frequency source by using the output feedback of the proportional-integral-differential control circuit to obtain an ultra-low phase noise microwave signal.

The invention discloses a device and a method for detecting organic matter components in space dust. The device comprises a pyrolysis cabin and an electronics box which are communicated end to end, a transparent window is arranged between the pyrolysis cabin and the electronics box, a front cover plate capable of being opened and closed is arranged at a head port of the transparent window, and a silicon dioxide aerogel plate is embedded in the front cover plate; the electronics box is internally provided with a macro magnification camera, an infrared laser unit, an infrared temperature measurement camera, a double-optical-comb spectrum unit, a main control unit and a power supply unit. According to the invention, dust or fragments floating in the space can be effectively captured and collected under the approaching environment of the space orbit of the earth or asteroid and other stars, and the captured sample is heated by using high-power infrared laser, so that organic matters and water in the sample are heated, decomposed and volatilized; and then carrying out qualitative and quantitative analysis work on volatile matters by using a double-optical comb spectrometer, so as to realize high-precision, high-sensitivity and high-resolution in-situ detection analysis on space dust.

The invention discloses a dispersion engineering method of an ultra-flat soliton micro-cavity optical comb, which belongs to the technical field of optical frequency comb generation and comprises the following steps: S1, determining geometric structure parameters related to optimization of micro-ring cavity integrated dispersion; s2, constructing a data set required by neural network training; s3, establishing a full-connection neural network model; s4, predicting the geometric structure parameters of the micro-ring cavity for the target integrated dispersion curve through the model in the S3, the method is suitable for different photon integration platforms and micro-cavity structures, the actual micro-nano preparation process can be guided, the neural network model is used, the micro-ring cavity structure parameters are directly obtained through the target dispersion curve, and the accuracy of the micro-ring cavity structure parameters is improved. The complexity of parameter optimization is reduced, and the training time of the model is greatly shortened by preprocessing the data set.

The invention discloses a full-locking integrated microcavity optical comb based on coherent population trapping spectral lines, and belongs to the technical field of integrated microcavity optical combs. The full-locking integrated micro-cavity optical comb comprises a laser generation module, a frequency reference subsystem and a micro-cavity optical comb system. The laser generation module is used for generating two paths of laser, the frequency reference subsystem modulates one path of laser, a modulated optical signal is emitted into the atomic gas chamber system, and after transmission light is demodulated and subjected to phase-locked amplification processing, an optical frequency signal and a microwave signal which are locked to an atomic spectral line are obtained; and the optical frequency signal is fed back to the laser generating module to realize optical frequency locking. And the microcavity optical comb system adopts a microwave signal generated by the frequency reference subsystem as a frequency reference, and modulates the other path of laser to serve as pump light to enter the optical microcavity, so that optical comb output of a soliton state in the optical microcavity is realized. According to the invention, a single quantum system is taken as a reference, the problem of full locking of the micro-cavity optical frequency comb is effectively solved, and the system integration degree is relatively high.

The invention discloses an on-chip time-frequency transmission system and method based on an octave optical comb and an electro-optical modulation optical comb, and the method comprises the steps: constructing a chip-based optical reference cavity through the technologies of vacuum optical cement, photoresist backflow and the like, and achieving an on-chip ultra-stable laser through a phase modulator and a reflection separation optical path; an on-chip laser source pumping micro-ring resonant cavity is utilized to generate an octave optical frequency comb, frequency multiplication is carried out on the on-chip laser source pumping micro-ring resonant cavity and an additional laser source to realize detection and locking of carrier envelope offset frequency (fceo), frequency beating is carried out on the on-chip laser source pumping micro-ring resonant cavity and the on-chip ultra-stable laser device to realize frequency beating (fbeam) locking, and the laser source is utilized to generate an electro-optical modulation optical frequency comb through a circulating phase modulator to realize frequency beating and locking of the on-chip ultra-stable laser device. And the optical time frequency is locked with the locked octave optical comb, is sent to a far end after polarization control and light amplification, and simultaneously receives an electro-optical modulation optical comb at the far end and performs linear light sampling, so that the transmission of the optical time frequency is realized. The optical fiber or space optical link time-frequency transmission device can realize optical fiber or space optical link time-frequency transmission, and has the advantages of low overall noise, high transmission precision, compact structure, small size, low power consumption and the like.

The invention discloses a pulse compression double-optical comb frequency modulation continuous wave laser ranging device and method, the device comprises an FMCW light source, a beam splitter, a detection light channel, a reference light channel, a beam combiner and a processing module, the FMCW light source outputs bidirectional linear frequency sweeping laser with the frequency sweeping bandwidth B and the frequency sweeping period 2T, and the bidirectional linear frequency sweeping laser is divided into detection light and reference light through the beam splitter. The detection optical channel, the first optical comb generating the comb tooth interval of fR, the reference optical channel and the second optical comb generating the comb tooth interval of fR + delta fR are used, two paths of signals are combined through the beam combiner and then input to the photoelectric detector to generate beat frequency signals, the processing module carries out rear-end data processing on the beat frequency signals, time domain signal splicing is achieved through the coherence of the double optical combs, and time domain signals are obtained. And the ranging precision is improved. According to the invention, the pulse compression technology is used to reduce the duty ratio of the detection light pulse and improve the ranging resolution; meanwhile, beat frequency signals are generated through the double-optical comb technology, time domain signal splicing is achieved through coherence between different comb teeth, the frequency sweeping bandwidth is equivalently improved, and the distance measuring precision is further improved.

The invention provides a double-optical-comb-cavity modulated gas measurement system and method based on electro-optical modulation, in the use process, a detection optical comb and a reference optical comb which are coherent are generated through a double-optical-comb output module, the detection optical comb enters a resonant cavity to interact with gas to be measured, and the reference optical comb directly reaches a data acquisition and analysis module; the data acquisition and analysis module is communicated with the resonant cavity and the double-optical-comb output module, and is used for receiving the reference optical comb and the detection optical comb output from the resonant cavity, and performing component and concentration analysis on the to-be-detected gas according to the detection optical comb and the reference optical comb; in the measuring process, the electro-optical modulation module is used for acquiring the detection optical comb output from the resonant cavity in real time, and the optical field of the detection optical comb in the resonant cavity is dynamically modulated based on the detection optical comb, so that the optical comb mode is matched with the free spectral range of the resonant cavity in real time, and efficient coupling is formed in the resonant cavity; the influence of the gas dispersion effect on the measurement precision is eliminated.

An optical comb generator receives light from at least two continuous wave laser sources, produces a different frequency comb from each laser source, and produces an output that it the simultaneous combination of the different frequency combs. The different frequency combs span different frequency bands, but at least partially overlap in frequency with an adjacent comb in a region of overlap. A spectral filter produces a filtered output that has at least one pair of tones from the region of overlap, the pair of tones comprising one tone from each of two adjacent combs. Feedback control based on the filtered output is applied to adjust the light entering the comb generator such that the frequencies and phases of the pair of tones from the region of overlap are aligned. In this way, the multiple different overlapping combs are stitched together to form a single seamless comb spanning a broader frequency range.

A double-optical comb coherent Raman spectrum background noise suppression system for probe light delay regulation is characterized in that a first spectroscope for dividing laser emitted by an optical frequency comb light source module into probe light and pump light is arranged in a probe light delay regulation module, and an optical delay line is arranged to apply delay amount to the probe light; the characteristic that the attenuation time of coherent Raman spectrum signals is longer than that of background noise is utilized, detection light with delay amount is used for detection, the purpose of suppressing the background noise is achieved, the signal-to-noise ratio of a double-optical-comb coherent Raman spectrum measurement system is improved, and spectral signal distortion is suppressed.

The invention discloses a pattern wafer multi-parameter synchronous detection system and method based on double optical combs, and belongs to the field of wafer quality detection. The system comprises a signal light path, a reference light path, a detection light path and a synchronous detection module. After interference, the detection light beam and the reference light beam are decomposed into an H path and a V path through the polarization beam splitter, and are synchronously detected by the first camera and the second camera. The invention also provides a method which comprises the following steps: synchronously acquiring two paths of time domain interference data; fourier transform is carried out on each pixel point to obtain a plurality of spectrum pairs; the processing unit decodes in parallel based on the spectrum pair, and synchronously inverts multi-dimensional physical parameters such as three-dimensional morphology, stress and film parameters of the pattern wafer; and finally, comparing and identifying defects. According to the method, the problems of low detection efficiency and single information dimension in the prior art are solved, and wide-field, high-speed, high-precision and multi-parameter synchronous comprehensive characterization is realized.

The invention discloses a femtosecond optical comb large-size precision absolute distance measurement system in a complex environment. Comprising a source module, a beam splitter, a third dichroic mirror, a fundamental frequency femtosecond optical comb reference detector, a frequency doubling femtosecond optical comb reference detector, a fourth dichroic mirror, a frequency doubling femtosecond optical comb measurement detector, a fundamental frequency femtosecond optical comb measurement detector, a phase discriminator, a ranging zero point mirror and a corner reflector. The source module comprises an atomic clock, a femtosecond optical comb, an optical fiber beam splitter, a signal generator, an electro-optical modulator, a lens, a frequency multiplication module, a first collimation beam expander, a second collimation beam expander, a first dichroic mirror and a second dichroic mirror. According to the scheme, the defects that in the prior art, the measurement range is insufficient, complex industrial sites are difficult to adapt, and the real-time performance is poor are overcome, and a new way is provided for breaking through the technical bottleneck of large-range, high-precision, dead-zone-free, rapid and real-time measurement in a complex environment; and a technical support is provided for engineering application of a femtosecond optical comb precision distance measurement technology and development of a subsequent measurement prototype.

The invention discloses a multi-band enhanced infrared optical comb spectrum rare gas detection system in a hollow cavity of building glass, which is characterized in that a line scanning optical frequency comb light source module and a reflective array module jointly form a virtual enhanced cavity to enhance the optical path of an emitted fan-shaped optical comb light beam so as to improve the detection precision; rapid switching of multi-band gas is achieved through an electric filter wheel according to sequential control so as to detect different gases, gas data in a hollow cavity are collected in real time by combining the high-speed collection capacity of a dual-band area array detection module, and a concentration distribution cloud chart of argon and krypton is rapidly constructed based on a data terminal processing module; the detection efficiency and accuracy of the gas in the glass hollow cavity are greatly improved, the synchronous operation of space scanning and wave band switching is realized, and multi-dimensional data of the concentration, the position and the impurity content of multiple gases can be measured and obtained at a time; a polarization filtering function and a temperature field compensation algorithm are integrated, and the detection precision under outdoor strong light and temperature difference environments is ensured.

The invention discloses a dual-wavelength mode-locked laser generating device and a dual-wavelength mode-locked laser generating method, and belongs to the technical field of optical communication, and the dual-wavelength mode-locked laser generating device comprises a pumping source, an optical integration module, a gain optical fiber, a saturable absorber and a dual-wavelength pulse independent polarization mode linear coupling regulation and control structure, linear coupling strength of cross-polarization components in two wavelength pulses is independently regulated and controlled by using a structure of a polarization controller and a polarization maintaining optical fiber, and dual-wavelength mode-locked pulse laser of different types of pulse combinations can be obtained. The coherent pulse light source with unique spectral characteristics can provide a low-cost light source for the fields of high repetition frequency optical combs, all-fiber architecture high repetition frequency soliton sequences and microwave photonics.

The invention relates to the technical field of quantum key distribution, in particular to a quantum key distribution device and method based on soliton optical combs. A soliton optical comb chip is used as a light source, the light source enters a quantum key coding chip, quantum state coding is achieved after pulse light generation, wavelength multiplexing, multi-quantum key protocol coding and light attenuation, and the light source is input to a multi-wavelength multi-path optical switching chip for path selection. After passing through the optical fiber channel, the signal light is input into the quantum key decoding chip to be decoded and detected. According to the invention, multiple users can use different protocols to carry out quantum key distribution, quantum states carrying different coding modes carry out quantum communication with different communication parties based on wavelength decoupling, and construction of a quantum communication network can be supported.

The invention discloses a wavelength and repetition frequency independent adjustable gain-competition-free polarization-maintaining fiber common-cavity double-optical-comb mode-locked laser and an adjusting method, and relates to the technical field of optical frequency combs. In order to solve the problems that a system is easily influenced by an external environment, the anti-interference capability is poor and gain competition exists between optical combs due to the existence of a single-mode optical fiber in an existing optical fiber double-optical-comb structure, the invention provides an optical fiber double-optical-comb structure. According to the technical scheme, the laser comprises a polarization-maintaining pump laser, a first polarization-maintaining optical fiber coupler, a polarization-maintaining optical fiber wavelength division multiplexer, a polarization-maintaining ytterbium-doped optical fiber, a polarization-maintaining collimator and a blazed grating, laser output by a second polarization-maintaining optical fiber coupler is combined through a polarization-maintaining polarization beam combiner, and the polarization-maintaining polarization beam combiner serves as a horizontal polarizer and a vertical polarizer; the separated polarized laser is respectively coupled to a slow axis and a fast axis of a common-end tail fiber, and a semiconductor saturable absorber is used as a reflection end face. According to the invention, a full polarization-maintaining structure is adopted, the external environment resistance is strong, and the stability is greatly improved.

The invention discloses an optical comb frequency control system and method for a photo-generated ultra-stable microwave source, and the system comprises at least one optical comb signal frequency adjustment loop which comprises an optical frequency comb, a phase discriminator, a phase difference extraction circuit, and a PID circuit. The output end of the optical frequency comb is electrically connected with the input end of the phase discriminator, one input end of the phase discriminator is also connected with a reference signal, the output end of the phase discriminator is electrically connected with the input end of the phase difference extraction circuit, the output end of the phase difference extraction circuit is electrically connected with the input end of the PID circuit, and the output end of the PID circuit is electrically connected with the input end of the optical frequency comb. According to the invention, an optical comb frequency control system with a larger phase discrimination range, lower bottom noise and higher gain bandwidth can be realized.

The invention relates to the technical field of ultrafast laser and light quantum, and provides a single-cavity double-optical-comb absolute distance measurement system and method based on repetition frequency scanning. The system comprises a single-cavity double-optical comb system which is used for simultaneously establishing clockwise and anticlockwise propagating mode-locked pulses in an annular cavity through a bidirectional pumping source and outputting a main oscillation optical comb and a local oscillation optical comb through a polarization maintaining optical fiber coupler; a first piezoelectric ceramic and a second piezoelectric ceramic are arranged in the annular cavity, and the first piezoelectric ceramic and the second piezoelectric ceramic are adjusted through a differential driving mode so as to lock and regulate the repetition frequency difference between the main oscillation optical comb and the local oscillation optical comb; the double-optical-comb distance measuring system is used for combining the main oscillation optical comb passing through the Michelson interferometer with the local oscillation optical comb not passing through the Michelson interferometer to generate a radio frequency beat frequency signal; and calculating the real-time absolute distance of the measured target according to the optical path difference of the radio frequency beat frequency signal and the repetition frequency difference of the main oscillation optical comb and the local oscillation optical comb.

The invention discloses a surface topography detection method and system based on double optical comb surface domain frequency sweeping, and relates to the technical field of surface topography detection. According to the method and the device, the frequency sweeping function of the double optical combs is realized by utilizing the area domain frequency sweeping, so that the double optical comb light source capable of realizing high-precision distance measurement can be applied to an interference light path to realize area array distance measurement. Therefore, double-optical-comb frequency sweeping is used for replacing traditional light source frequency sweeping, double-optical-comb multi-heterodyne interference is combined with surface domain frequency sweeping, the measurement precision of the longitudinal depth is greatly improved, then the precision of three-dimensional reconstruction based on the longitudinal depth is improved, the ultra-high resolution ratio which breaks through the micron level and reaches the sub-nanometer level is achieved, and actually, the measurement precision of the longitudinal depth is improved. The atomic-scale surface topography detection with the longitudinal resolution being less than or equal to 0.1 nm can be realized.

The invention discloses a high-precision double-optical-comb speed measurement method and device. The method comprises the steps that a double-optical-comb system with a signal optical comb and a local oscillator optical comb is arranged; a target object is arranged in a distance measuring light path system, and the distance measuring light path system is debugged to enable signal light combs of a measuring arm and a reference arm to generate interference signals with local oscillator light combs; adjusting the center frequency of radio frequency spectrum comb teeth of the double optical combs to ensure that the radio frequency spectrum corresponding to the interference signal is in a non-aliasing interval; when the target object is in a moving state, collecting a non-aliasing interference signal of the ranging light path system, and calculating a to-be-measured non-fuzzy distance of the target object in real time based on the non-aliasing interference signal; and subtracting two adjacent groups of to-be-measured non-fuzzy distances of the target object, and calculating to obtain a speed value of the target object. Therefore, the influence of the actual repetition frequency difference change caused by the target motion of the measuring arm on the speed estimation can be corrected.

The invention relates to the technical field of spectral measurement, in particular to a quantum correlation enhanced optical comb spectrum device and method, and the method comprises the steps: processing pump light and seed light to obtain idler frequency light and intrinsic light with quantum correlation; performing time domain matching adjustment on the idle frequency light, and reflecting the idle frequency light after the time domain matching adjustment to obtain a time-matched quantum correlation light beam; combining the intrinsic light and a continuous laser to obtain a first combined light; the mid-infrared light comb generates mid-infrared light carrying gas information after penetrating through the sample cell containing the gas to be detected; the light after the first beam combination and the mid-infrared light carrying the gas information are combined to obtain light after the second beam combination, frequency conversion processing is carried out, and then a near-infrared light comb is output; and processing the quantum correlation light beam and the near-infrared light comb which are matched in time, and outputting a double-light comb signal. Through combination of a quantum correlation mechanism and a frequency conversion technology, the intermediate infrared spectrum detection signal-to-noise ratio is remarkably improved, and high-sensitivity and high-speed parallel quantum enhanced spectrum is realized.

The invention discloses a spatial moving target optical comb rapid distance measurement method and system based on a hierarchical guidance strategy, relates to the technical field of spatial moving target distance measurement, and aims to solve the problems of long alignment time, high energy consumption and high efficiency caused by the fact that traditional optical alignment before moving target scanning depends on a preset global scanning mode. And the requirements of dynamic tracking distance measurement are difficult to meet. The system is divided into a laser emitting and scanning part, an image receiving and processing part and a processor part. The laser emission scanning part utilizes the deflection of a fast reflecting mirror to change a laser light path, and scans a reflecting prism on the surface of a target; the image receiving and processing part reflects an image of a target reflecting prism to a binocular camera through a small fast reflecting mirror, and then inputs an imaging result of the camera into an image processing module to calculate a relative pose with a target; and the main processor performs target motion estimation and scanning path planning according to the relative pose information, and inputs reference path information to the fast steering mirror driving circuit to implement tracking control. Through a multi-sensor fusion sensing algorithm, accurate target sensing and positioning in a complex space environment are realized, interference such as in-orbit platform vibration and space illumination condition change under a microgravity condition can be effectively coped with, and thus the robustness and accuracy of space target detection are greatly improved.

The invention relates to a double-optical-comb laser and a laser spectrum measurement system, and the double-optical-comb laser comprises a pumping source which is used for generating pumping light. The optical fiber amplifier is connected with the output end of the pumping source, and the output end of the optical fiber amplifier is connected with the first optical fiber coupler. The first optical fiber coupler is connected with the first mode-locked laser cavity and the second mode-locked laser cavity. An output light path of the first mode-locked laser cavity is connected with the second optical fiber coupler, an output light path of the second mode-locked laser cavity is connected with the second optical fiber coupler, and the second optical fiber coupler is used for carrying out beam combination and frequency beating on the two paths of laser. The optical path delay line is used for adjusting the laser repetition frequency difference between the first mode-locked laser cavity and the second mode-locked laser cavity. The double-optical-comb laser not only overcomes the defects that an existing double-optical-comb system is complex, expensive and inconvenient to tune, but also has the advantages of being compact in structure, high in stability, high in output pulse energy and tunable in repetition frequency difference.

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 full-locking femtosecond optical frequency comb device which comprises an optical system module, a first locking module and a second locking module, and the optical system module comprises a laser and is used for generating laser. The first locking module is used for receiving the first locking control signal, sending the first locking control signal to the optical system module and adjusting the repetition frequency of the first to-be-locked laser, the first to-be-locked laser becomes third to-be-locked laser, and the third to-be-locked laser enters the second locking module; and the second locking module is used for receiving the second locking passive feedback signal, sending the second locking passive feedback signal to the optical system module and then adjusting the carrier envelope phase shift frequency of the third to-be-locked laser, so that the third to-be-locked laser becomes laser with a stable target frequency. The device has the advantages of being simple in structure, stable and reliable, can effectively solve the tight locking problem from the solid-state optical comb to the optical frequency reference, and provides an optimal scheme for optical clock comparison.

The invention relates to the technical field of optical comb wavelength calibration, in particular to a wavelength calibration device and method of an injection type locking optical comb, which can be used for optical comb wavelength calibration of an injection type locking method. According to the femtosecond laser frequency comb, injection type locking is adopted, complex optical and electrical locking needed by a traditional femtosecond laser frequency comb is avoided, and the system structure is greatly simplified. The cost of the system is reduced, and the reliability and the stability of the system are improved. The beat frequency process is realized by using the narrow linewidth laser and the photoelectric detector, and the wavelength change of the mid-infrared light frequency comb can be monitored in real time.

Method for measuring the spectral response of a linear system, which comprises injecting a first optical comb or probe comb into a system to be spectrally sampled, at a first repetition rate Δf, the bandwidth of the probe comb being N·Δf, gathering the optical output signal from the system to be spectrally sampled, beating the optical output signal with a local oscillator signal to generate a beating signal, wherein the local oscillator signal comprises a second optical frequency comb, at a second repetition rate that is an integer multiple of the first repetition rate plus an offset, Δf'=M·Δf+δf, with M any positive integer. The invention also relates to a system for carrying out the method.

According to the spectrum peak online calibration system and method for double-optical-comb coherent Raman spectrum measurement, a calibration sample of a Raman shift wave number corresponding to a known spectrum peak is arranged in a spectrum peak calibration module, a coherent Raman spectrum of the calibration sample is measured, and a transformation function of delay and the Raman shift wave number is calculated; the spectrum peak on-line calibration device realizes spectrum peak on-line calibration of double-optical-comb coherent Raman spectrum measurement, is beneficial for reducing spectrum peak calibration deviation caused by system fluctuation, and is characterized by comprising an optical comb light source module, a dispersion regulation and control module, a spectrum peak calibration module and a sample detection module which are connected in sequence, the optical comb light source module generates pump light and Stokes light which are different in frequency and vertical in polarization, and the Stokes light is connected with the optical comb light source module. The dispersion regulation and control module enables the pump light and the Stokes light to form combined light, the spectrum peak calibration module divides the combined light into transmission light and reflection light, the reflection light acts on a calibration sample to generate a calibration spectrum signal, and the transmission light acts on the sample to measure a coherent Raman spectrum signal of the sample. And the spectrum signals and the calibration spectrum signals are recorded by the high-speed data acquisition system and input into an upper computer.

The invention discloses an all-optical-fiber liquid level measuring system and method based on double-optical-comb phase decoupling and self-adaptive compensation, and the system comprises a double-optical-comb light source module, an optical fiber coupling module, a signal collection and processing system, a self-adaptive compensation module, a measuring arm and a reference arm. The optical fiber coupling module comprises a polarization-maintaining optical fiber beam splitter and a polarization-maintaining optical fiber beam combiner; the signal acquisition and processing system comprises a balance detector, a lock-in amplifier and an upper computer which are sequentially connected from front to back, and the lock-in amplifier is connected with a self-adaptive compensation module; the double-optical-comb light source module is connected with the measuring arm and the reference arm through the polarization-maintaining optical fiber beam splitter, and the measuring arm and the reference arm are connected with the balance detector through the polarization-maintaining optical fiber beam combiner. According to the invention, interference signal intensity and phase information are combined, the problem of reflectivity difference between transparent liquid and opaque liquid is solved, phase noise caused by environmental disturbance is eliminated, and the measurement stability is improved. According to the invention, non-contact, real-time and high-resolution measurement of the height of the liquid level is realized, especially measurement in a high-pressure, high-temperature or corrosive environment is realized, and the application range is expanded.

The invention provides a terahertz frequency comb generation verification method and system based on an optical fiber microcavity optical frequency comb, and the method comprises the steps: injecting a continuous wave laser into an optical fiber microcavity resonator to generate a stable Kerr optical frequency comb, enabling the Kerr optical frequency comb to work in a single soliton state or a soliton crystal state, and obtaining an optical frequency reference with low phase noise. Furthermore, spectrum selection is performed on the optical frequency comb, multiple groups of optical comb tooth pairs comprising comb teeth of different orders are actively selected, and the optical frequency difference of each group of comb tooth pairs is directly converted into an electric signal in a terahertz frequency band by utilizing a beat frequency effect of a photoelectric detector. A plurality of terahertz electric signals generated by different comb tooth pairs are integrated to form a multi-channel terahertz frequency comb. The method allows a plurality of discrete and frequency-controllable terahertz signal channels to be generated in parallel on a single optical platform through one-time optical processing and photoelectric conversion, so that multichannel terahertz frequency comb generation is realized.