487 results about "Optical frequency comb" patented technology

The invention discloses an optical frequency comb generation method and device based on Brillouin scattering and an electro-optical modulator, and belongs to the field of photoelectric measurement. The method comprises the steps that a first laser and a second laser are used for generating pump light and seed light respectively, multi-wavelength pump light is generated through a cascade electro-optical modulator, the pump light and the seed light are emitted into a Sagnac loop, an optical frequency comb is output through the forward Brillouin scattering effect of an optical fiber and the electro-optical modulator, and the seed light and the pump light are output. The polarization controller is adjusted to optimize polarization state matching of the pump light and the seed light, so that the Brillouin scattering effect reaches the maximum value. The device is composed of a laser, an electro-optical modulator, a signal generator, an optical amplifier, an optical isolator, an optical coupler, a polarization controller and an optical fiber. The optical fiber forward Brillouin scattering effect and the electro-optical modulator are combined, the optical frequency comb giving consideration to the wide frequency spectrum and the narrow interval is generated, meanwhile, the comb tooth interval of the optical frequency comb can be accurately controlled by independently adjusting the frequency of the signal generator, and accurate measurement of signals or objects is achieved.

The invention discloses a double-comb non-cooperative target ranging system based on single photon detection, which is characterized in that an optical pulse output by a first optical frequency comb is divided into two paths of light through a first beam splitter, the first path of light is combined with one of two paths of light divided by a second optical frequency comb through a second beam splitter, and the combined light is transmitted to a first nonlinear frequency up-conversion module; a sum frequency light pulse in the wave band of 780 nm is generated and detected by a base avalanche diode photoelectric detector, and then a time-dependent single photon counter is triggered to start counting; the second path of light is output to a beam expanding collimator through the circulator and irradiates a target to be measured through spatial propagation, the beam expanding collimator collects diffuse reflection light and returns the diffuse reflection light to a third port of the circulator along the original path, and the diffuse reflection light and the other path of light split by the second optical frequency comb through the second beam splitter are combined and transmitted to a second nonlinear frequency up-conversion module; the up-conversion light after sum frequency conversion passes through the optical filter group and then is recorded by a stop end of the single photon counting module, multi-cycle accumulative statistics is carried out by the time correlation single photon counter, and finally a photon counting waveform is reconstructed and the flight time difference of the to-be-measured target is calculated by the computer.

The invention relates to an integrated microcavity optical comb repetition frequency and optical frequency locking device and method, and belongs to the technical field of integrated microcavity optical combs. The locking device comprises a pumping module, a power amplification module, a phase modulation module, an electro-optic driving module, an acousto-optic modulation module, an acousto-optic driving module, a band-pass filtering module, a micro-ring resonant cavity and a beam splitting module; the device comprises a soliton detection module, a control module, a repetition frequency detection module, a first feedback control module, an acetylene frequency stabilized laser, a beat frequency module, an optical frequency beat frequency detection module and a second feedback control module. The locking device can achieve full frequency locking of the microcavity optical comb, has the advantages of being high in frequency stability, wide in servo bandwidth, simple and compact in structure, tight in locking, low in noise, high in reliability and low in cost, and can provide a powerful tool for the field of precision measurement.

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 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 provides a detection system of a micro optical fiber coupler based on a bidirectional optical frequency comb vernier effect, which can be applied to the technical field of photoelectric detection. The system comprises: an optical frequency comb light source configured to emit detection light; the beam splitter is arranged to split the detection light into first sub-detection light and second sub-detection light; the reference sensing unit is arranged to guide the first sub detection light to interact with a reference solution through an evanescent field of the first micro optical fiber coupler so as to output first transmission light; the detection sensing unit is arranged to guide the second sub detection light to interact with the solution to be detected through an evanescent field of the second micro optical fiber coupler so as to output second transmission light; the beam combiner is set to combine the first transmission light and the second transmission light to obtain a combined light spectrum; the spectrum analyzer is set to collect the combined light and generate a vernier spectrum; and the processor is set to determine the concentration of the liquid to be detected according to the vernier spectrum.

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.

Disclosed herein is an optical frequency comb generator for a distributed acoustic anomaly detection system. The system can include a continuous wave frequency modulated laser source configured to generate a laser signal. The system can include an acousto-optical modulator configured to modulate the laser signal by altering an amplitude and / or frequency of the laser signal based on an RF drive signal applied to the AOM, and to output an optical pulse with multiple frequency sidebands based on the modulation. The output can form an optical frequency comb usable detecting and locating acoustic anomalies within a structure under observation.

The invention discloses a method and a system for measuring gravitational potential by a satellite-air-ground optical clock time-frequency comparison system. According to the method for measuring the gravitational potential, an optical clock superior to 110-18 orders of magnitude serves as the basis, a free space time-frequency comparison link based on an optical frequency comb serves as a bridge, the optical clocks among the satellite, the air and the ground are connected, high-precision time-frequency transmission is carried out, a gravity frequency shift signal is accurately extracted through time-frequency comparison of a remote clock, and the gravitational potential is measured. And then the gravity potential difference of the position where the remote clock is located is obtained by using a gravity frequency shift equation, and the gravity potential difference between air and ground or between any ground stations is determined.

According to the optical fiber interference sensor and the application method thereof, an electro-optical frequency comb is introduced to screen out two comb lines to form a photon-assisted millimeter wave light source, interference is carried out in two frequency spectral regions subsequently, common phase fluctuation is counteracted based on inherent phase coherence, and the strict requirement for the line width index of a laser is avoided. Meanwhile, the two acoustic optical modulators connected in parallel are introduced into the reference arm and the interference arm for frequency shift, the problem of co-frequency crosstalk caused by residual zero-order diffraction of the acoustic optical modulators is solved, and the sensing precision is substantially improved.

The invention discloses an ultra-wideband femtosecond optical parametric oscillator capable of being quickly tuned, and relates to the technical field of optical parametric oscillators. The oscillator comprises a frequency doubling device, an optical parametric oscillator resonant cavity device and a dispersion compensation chirp mirror pair module. According to the invention, the original phase matching bandwidth is further broken through by adopting a non-collinear phase matching mode that the transmission included angle between the pump light and the signal light is 2.5 degrees, and rapid wavelength tuning can be realized only by finely tuning the cavity length under the condition that the angle of the nonlinear crystal is not adjusted; the broadband tunable optical parametric oscillator can break through the bottlenecks in the aspects of wavelength tuning range, wavelength tuning speed and the like of the existing near-infrared optical parametric oscillator, and provides a novel light source with larger wavelength tuning range and higher tuning speed for the fields needing broadband tunable light sources, such as spectroscopy, micro-nano processing, optical frequency combs and the like.

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.

The invention belongs to the technical field of optical frequency comb repetition frequency, and discloses an optical frequency comb repetition frequency control system and a locking method, and the system comprises a light source module, a signal detection module, a frequency measurement module, a comparison frequency generation module and a feedback control module. The light source module generates an optical frequency comb; the signal detection module converts the optical signal into an electric signal, noise reduction and amplification processing are carried out through a signal processor, and noise reduction adopts a wavelet transform method; the frequency measurement module adopts a dual measurement mode of a frequency counter and a spectrum analyzer to accurately measure repetition frequency; the comparison frequency generation module provides high-precision reference frequency; and the feedback control module performs closed-loop adjustment according to the difference value between the measurement frequency and the reference frequency. By optimizing signal processing and adopting dual-frequency measurement and closed-loop feedback control, the problems of weak electric signals, large noise interference and low frequency control precision in the prior art are effectively solved, and the stability and accuracy of the repetition frequency of the optical frequency comb are improved.

The invention discloses a DP-MZM-based reconfigurable mixer with phase shift and image rejection functions, and belongs to the field of microwave photon signal processing. By adjusting an input radio frequency signal and a direct current bias voltage of the DP-MZM1, four different LO frequency doubling and mixing functions can be realized. By controlling the angle alpha between the polarization direction of the polarization analyzer and one axis of the modulator, the phase of the generated signal can be flexibly tuned in the range of 0-360 degrees. When combined with the optical frequency comb, the multi-channel multi-band frequency conversion system can be expanded into a multi-channel multi-band frequency conversion system with independent phase tuning capability by utilizing the channel switching and frequency slot selection functions of the wavelength selection switch, and parallel output of various frequency mixing results can be realized. By adjusting the phase difference between the two-channel output signals, I / Q mixing, double-balanced mixing and image rejection mixing can be configured. The scheme is not influenced by direct current bias drift, the system complexity is reduced, and the frequency conversion efficiency is improved.

A photonic-crystal resonator (PhCR) and associated methods of design and manufacture. The PhCR includes spontaneous optical-pulse generation and includes a ring whose geometry is correlated to a mode structure or dispersion of the PhCR while also taking into account a desired type of nonlinear optical output from the PhCR, such as an optical frequency comb, or a particular type of pulse. The PhCR includes a periodic nanopatterning on an inner radial wall of its ring and is able to spontaneously generate a nonlinear optical output. The nanopatterning of the inner radial wall is designed to form a desired output, such as one of a classic soliton pulse that has a sech type temporal profile, or a gaussian profile, or a sink pulse profile.

The invention discloses an optical communication wavelength meter for exciting rubidium atom two-photon transition based on a lithium niobate microcavity optical comb. The optical communication wavelength meter comprises a microcavity optical comb module, a repetition frequency phase-locked loop, an initial frequency phase-locked loop, a rubidium atom gas chamber and a frequency-stabilized light source. The micro-cavity optical comb module is used for generating a fundamental frequency optical comb and a frequency doubling optical comb, rubidium atom two-photon transition is directly excited, the frequency stabilization light source achieves frequency stabilization through rubidium atom saturation absorption, and the repetition frequency phase-locked loop feeds back and adjusts repetition frequency according to error signals of two-photon transition fluorescence intensity. The initial frequency phase-locked loop feeds back and adjusts the initial frequency through beat frequency signals of the frequency multiplication optical comb and the frequency stabilization light source, and the two groups of phase-locked loops stabilize the frequency of the microcavity optical comb to two groups of transition energy levels, so that locking of the repetition frequency and the initial frequency is realized. According to the optical communication wavelength meter based on the lithium niobate microcavity optical comb excitation rubidium atom two-photon transition, the cross modulation effect in a pumping wavelength and pumping power combined adjustment mechanism is avoided, and the size of the optical communication wavelength meter is reduced.

An integrated photonics millimeter wave (MMW) radar communication system based on analog phase modulation scheme includes an integrated photonics MMW radar communication signal transmitter, a radar receiver, and a communication receiver. The transmitter includes a radar communication signal analog phase modulation module, an optical frequency comb (OFC) module, an electro-optic modulator (EOM), an optical shaping filter, an optical power divider, a photoelectric detector, an electric power amplifier, and a transmitting antenna that are cascaded sequentially. The radar receiver includes a radar receiving antenna, an electric low-noise amplifier (LNA), an optical phase modulator, an optical bandpass filter (BPF), a low-speed photoelectric detector, an electric low-pass filter, and a low-speed oscilloscope that are cascaded sequentially. In the communication receiver, a communication receiving antenna is sequentially cascaded with an electric LNA, a frequency mixer, and an oscilloscope, and a voltage-controlled oscillator is cascaded with a frequency multiplier and then connected to the frequency mixer.

The invention discloses a distributed MIMO (Multiple Input Multiple Output) integrated system and method based on a reconfigurable notch chaotic optoelectronic oscillator, belongs to the field of microwave photons, and solves the problems of spectrum resource conflict, difficulty in multi-node synchronization, discrete inductance functions and the like. According to the system, a plurality of independent chaotic OEOs are combined with an optical frequency comb to drive an FIR filtering effect, MIMO chaotic signals with reconfigurable notch frequency points and quantity are generated, and dynamic allocation of spectrum resources is realized. The notch frequency band is used as a communication channel embedded modulation signal, and supports multi-spectrum sharing with 2.4 G, 5G, Wi-Fi and the like; a non-notch frequency band is reserved as a radar signal, and the range resolution is improved by using the broadband characteristic of the chaotic waveform. The star topology optical network expands the coverage area of a distributed system, and a centralized processing architecture reduces the complexity of multi-node collaboration. The invention provides an integrated solution of high-precision environment perception and high-reliability communication for smart cities, Internet of Vehicles and the like, and is suitable for dense urban areas with resource shortage and dynamic multi-service environments.

The invention provides a time stretching Fourier transform optical frequency comb morphology measurement system and method. The time stretching Fourier transform optical frequency comb morphology measurement system comprises an optical frequency comb OFC, an interferometer module, a dispersion optical fiber module, a signal detection module and a synchronous control module. An optical frequency comb (OFC) provides an incident light beam for the interferometer; the interferometer module obtains an interference signal of the measured object by adjusting the length of the single-mode optical fiber; the dispersion transmission module performs time stretching on the interference signal through a single-mode optical fiber to generate a time domain interference signal; a signal detection module captures the stretched time domain interference signal, and solves the morphology parameters of the measured object through a time-frequency transformation algorithm; the synchronous control module drives the two-dimensional displacement platform bearing the measured object through the motion control card and triggers synchronous acquisition and storage of three-dimensional shape data of the measured object. The method has enough high precision in morphology measurement, and the detection speed of the method can meet the requirements of industrial real-time detection.

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 provides a full-automatic parameter measurement system and method for a micro-cavity optical chip, and the system achieves the automatic measurement of the characteristic parameters of the micro-cavity optical chip through integrating a DFB tunable laser light source, an isolator, an EDFA amplifier, an ASE filter, a fundamental frequency light band elimination filter, a selectable beam splitter, a VOA, a PD, a main control module and other components. The system is connected with a to-be-tested chip through a specific interface, and can automatically obtain a central wavelength change curve, a transmission spectrum characteristic afterglow map and an expected soliton state intensity range of the micro-cavity optical chip at each temperature. The invention aims to automatically test the characteristic parameters of the micro-cavity optical chip so as to assist in reducing the time generated by tuning the optical frequency comb by adopting the chip, and meanwhile, an expected soliton state intensity range is given to reduce the problem of excessive tuning, so that a pre-test process required in chip application is simplified, and great convenience is brought to debugging generation of the integrated optical frequency comb.

The invention relates to a sweep frequency optical frequency comb generation system and a generation method. Fourier mode locking is realized through a Fourier mode locking photoelectric oscillator system. The sweep frequency optical frequency comb generation system is a closed Fourier mode-locked laser loop which is composed of a first optical amplifier, an optical fiber isolator, a broadband filter, a polarization controller, a thin film lithium niobate optical chip, a signal generator, a dispersion compensation optical fiber and a first optical coupler; and a photoelectric oscillator loop is formed by a second optical coupler, a single-mode delay optical fiber, a second optical amplifier, a photoelectric detector, a narrow-band filter, a low-noise amplifier and an electric power divider. Time domain active mode locking and Fourier mode locking are carried out on the laser resonant cavity at the same time, synchronous modulation of multiple optical frequency comb modes is achieved, sweep frequency optical frequency comb signals with high repetition frequency, high modulation speed, high coherence length and high output power are generated, and tunable optical frequency comb and high-quality high-frequency microwave signal output can be provided at the same time.

The invention provides a start key type soliton micro-comb multi-line multiplexing system and a control method, and the system comprises a first soliton micro-comb generation and control module, a second soliton micro-comb generation and control module, a distance measurement module, a gas spectrum analysis module, a communication module and a processing module. The first soliton micro-comb generation and control module and the second soliton micro-comb generation and control module respectively generate a first soliton optical frequency comb and a second soliton optical frequency comb; the distance measurement module, the gas spectral analysis module and the communication module respectively output distance measurement data, gas spectral analysis data, a modulation signal and a local oscillation signal based on the first soliton optical frequency comb and the second soliton optical frequency comb; and the processing module receives the distance measurement data, the gas spectral analysis data, the modulation signal and the local oscillation signal and outputs a distance measurement result, a gas spectral analysis result and a modulation result. The system is simple in structure and operation, narrow in laser line width and excellent in performance, has no special requirements on the environment, and has reliability and robustness.

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 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.

Described herein is a data processing device (100) including an input (102) for receiving an input signal including a data stream to be processed. A reconfigurable transversal filter (106) is adapted to perform one or more temporal signal processing functions on the input signal to produce one or more processed output signals (110-114). Filter (106) includes an optical frequency comb generator (108) to generate a plurality of discrete, equally spaced frequency channels (116). Filter (106) also includes a modulator (132) configured to modulate the input signal with each frequency channel (116) to generate modulated frequency channels having the input data stream encoded therein. An optical delay device (136) selectively applies a frequency dependent temporal delay to each of the modulated frequency channels such that each of the modulated frequency channels are temporally shifted by a predefined temporal period to produce delayed modulated frequency channels. Filter (106) also includes an optical spectral shaper (138) is configured to selectively apply respective amplitude weightings to the frequency channels (116) before or after modulation and delay. Filter (106) further includes one or more photodetectors (140-144) configured to sum one or more of the delayed modulated frequency channels to generate the one or more processed output signals. Device (100) also includes a controller (130) configured to dynamically control the amplitude weightings to the frequency channels (116) to define the signal processing functions.

The invention provides an echo wall mode microcavity time-varying signal sensing method and system. The echo wall mode microcavity time-varying signal sensing method comprises the steps of S1, building an echo wall mode microcavity time-varying signal sensing experiment platform based on a double-optical-comb spectrum technology; s2, starting a dual-light frequency comb; s3, sensing a time-varying signal through coupling of a coupling device and the echo wall mode microcavity; s4, performing Fourier transform on the output of the reference path and the signal path within one sampling time, and extracting a time-varying signal by using a plurality of modes of the microcavity; and S5, repeatedly executing the step S4 until the measurement is finished. Time-varying parameter sensing is achieved through multiple modes of the microcavity, high sensitivity is achieved, meanwhile, high precision and a large dynamic range are achieved, and application of microcavity sensing is further expanded.

A system for generating a visible-to-mid-infrared frequency comb, including an all polarization-maintaining fiber-based frequency comb module and an optical frequency comb spectral expansion module. The all polarization-maintaining fiber-based frequency comb module is configured to generate a laser with evenly spaced and coherent frequencies and spectral lines. The optical frequency comb spectral expansion module is configured to perform spectral expansion on the laser to output the visible-to-mid-infrared frequency comb. The optical frequency comb spectral expansion module includes an amplifier, a 90:10 beam splitter, a first all polarization-maintaining compression fiber, a second all polarization-maintaining compression fiber, a 1100 nm-2350 nm supercontinuum unit and a 500 nm-1100 nm supercontinuum unit. A circuit of a semiconductor laser diode unit is configured to control output of the 1100 nm-2350 nm laser.

The invention provides a mid-infrared optical frequency comb. The mid-infrared optical frequency comb comprises a near-infrared optical frequency comb seed source of a polarization-maintaining all-fiber structure; the all-fiber nonlinear amplification and pulse compression module is connected with the near-infrared optical frequency comb seed source through a polarization maintaining fiber and is used for amplifying the power of the seed light and compressing the pulse width after generating a linear chirped pulse; the all-fiber nonlinear spectrum broadening module is connected with the all-fiber nonlinear amplification and pulse compression module through a polarization maintaining fiber and is used for broadening a laser spectrum; the difference frequency module is used for receiving the laser pulse processed by the all-fiber nonlinear spectrum broadening module and generating an intermediate infrared laser pulse through intra-pulse self-difference frequency; wherein the seed source, the all-fiber nonlinear amplification and pulse compression module and the all-fiber nonlinear spectrum broadening module are connected through a polarization maintaining fiber to form an all-fiber integrated structure. By adopting the scheme, the anti-interference capability of the system can be enhanced, miniaturization and high operation reliability are realized, the debugging process is simplified, and the difference frequency efficiency is improved.

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.