213 results about "Optical comb" patented technology

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 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.

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 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 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 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.

The present invention discloses a relay node download method and device based on an optical frequency comb. The present invention is used to address the problem of difficulty for nodes in obtaining frequency information transmitted in a link in a time-frequency information transmission system. The present invention is characterized in that an optical comb signal transmitted and a return optical comb signal in the optical comb-based time-frequency transmission system link are obtained through an optical coupling module. The transmitted optical comb signal is converted into an electrical signal through a photoelectric detection module, and then two electrical signals are obtained through a power distribution module. The center frequencies of the electrical bandpass filters connected to the two electrical signals are then adjusted to obtain low-order harmonic components and high-order harmonic components with a frequency doubled. The return optical comb signal is mirrored, and the two low-order harmonic components are connected to a phase detection module to obtain relative delay information. Based on this delay information, the high-order harmonic components are directly phase-shifted through a phase shift module to restore the original signal. Compared with the prior art, the present invention fully utilizes the characteristic of optical comb signals containing multiple frequency components, avoids the use of complex electrical components such as frequency dividers and multipliers, reduces costs, significantly reduces electrical noise at the download node, and improves the stability of node frequency extraction.

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.

This invention discloses a vehicle-mounted dual-optical-comb system for outdoor testing, comprising an oscillator module, a power amplifier module, a frequency conversion module, a gas measurement module, a signal detection, acquisition, and processing module, and a vehicle-mounted platform module. The oscillator module generates two optical frequency comb signals with slightly different repetition frequencies. The power amplifier module amplifies the two optical frequency comb signals. The frequency conversion module outputs a combined dual-optical-comb beam. The gas measurement module enables the dual-optical-comb beam to interact with the gas to be tested in an open environment. The signal detection, acquisition, and processing module receives the optical signal absorbed by the gas to be tested, converts it into an electrical signal, and acquires and processes the electrical signal to obtain the absorption spectrum information of the gas to be tested. The vehicle-mounted platform module is used to fix and install each module. The advantages of this invention are: stable operation, strong resistance to environmental interference, low power consumption, and suitability for long-term vehicle-mounted operation.

A light emitting device and method thereof, and a gas analysis system and method thereof, are disclosed. The light emitting device includes: an optical comb light source configured to generate an initial light signal; an encoding module configured to encode the initial light signal based on a preset comb code to form a light signal to be processed; and a modulation module configured to perform quantum noise compression on the light signal to be processed to form an emitted light signal. This invention belongs to the field of precision measurement. Through a collaborative architecture of "compressed optical comb + computational encoding," optical comb spectroscopy technology achieves improvements in multiple dimensions, including sensitivity, environmental adaptability, speed, and system complexity.

This invention relates to a dual-comb control system for a terahertz quantum cascade laser, comprising a first terahertz quantum cascade laser, a second terahertz quantum cascade laser, a first T-type biaser, and a second T-type biaser. The first terahertz quantum cascade laser operates in optical frequency comb mode, while the second terahertz quantum cascade laser operates above a threshold current. The first and second terahertz quantum cascade lasers emit terahertz light from each other. The first terahertz quantum cascade laser also functions as a detector to detect a mixing signal. The state of the mixing signal is switched by changing the power of the radio frequency signal generated by the radio frequency source. This invention enables the switching of the mixing signal between chaotic, unstable, and dual-comb states under high drive current, significantly improving the spectral width and application scenarios of the dual-comb system based on the quantum cascade laser.

In general aspects, a vapor cell sensor can be used to detect radio frequency (RF) electromagnetic radiation. In some aspects, the system includes a laser system configured to generate a laser signal including first and second laser signals. The system also includes an optical comb generator and a vapor cell sensor. The optical comb generator is configured to generate a comb spectrum based on the first laser signal. The comb spectrum includes comb lines at respective comb frequencies. The vapor cell sensor contains vapor and is configured to generate an optical spectrum based on the interaction of the vapor with the comb spectrum and the second laser signal. The system also includes an optical detector configured to detect characteristics of the optical spectrum at one or more of the comb frequencies.

The application discloses a kind of based on functional echo wall mode optical microbottle cavity Full light tuning controllable optical comb generation method. Including 1550nm narrow line width continuous wave laser, single-mode optical fiber, erbium-doped fiber amplifier, polarization controller, optical isolator, functional microbottle cavity-fiber taper coupling system, optical attenuator, optical spectrum analyzer and 1550nm power adjustable laser. The unique axial characteristics of echo wall mode microbottle cavity are used, the free spectral range of microcavity is reduced, the axial mode microcavity optical frequency comb with small free spectral range is generated, and based on full light tuning method, functional microbottle cavity is prepared, and the axial mode microcavity optical frequency comb generated is tuned by photo-thermal material titanium dioxide, and significant spectral range tuning is realized. The application solves the limitation that WGM microcavity optical frequency comb cannot be effectively tuned due to large free spectral range, and helps the practical application in the field of microcavity optical frequency comb optical communication, optical frequency synthesis and the like.

The invention discloses a distributed radar and laser radar system based on a chaotic optical comb, and belongs to the technical field of microwave photonics and laser. The distributed radar and laser radar system comprises a chaotic optical comb signal generation module, a wavelength division multiplexer, N optical fibers and N radar and laser radar modules. A chaotic optical comb signal generated by the chaotic optical comb signal generation module is divided into N single chaotic optical signals with different wavelengths in the wavelength division multiplexer; the N single chaotic optical signals with different wavelengths are respectively transmitted to the N radar and laser radar modules at different spatial positions through the N optical fibers, so that spatial distribution of the signals is realized. The single chaotic optical comb signal source is combined with the wavelength division multiplexer and the optical fiber, sensing signals are provided for a plurality of radar and laser radar modules which are arranged in a distributed mode, generation and distribution of multi-path distributed sensing signals are achieved, a traditional multi-source scheme is replaced, system cost, size and complexity are reduced, and compact 360-degree annular sensing array deployment is supported.

The invention discloses a high-performance optical comb laser based on heterogeneous material integration and multi-effect fusion, belongs to the technical field of optical communication and laser devices, and aims to solve the problems that a traditional optical comb laser is difficult to start tuning, low in power efficiency, large in line width or limited in bandwidth and the like. A scheme of heterogeneous integration of a III-V group gain material, a low-loss Si3N4 waveguide and a high-electro-optical coefficient barium titanate (BTO) material is adopted, an outer cavity chip comprises a high-Q-value annular resonant cavity, an electro-optical comb is generated by modulating the annular resonant cavity, then a Kerr comb is excited, and the optical comb is amplified through gain. According to the invention, three mechanisms of electro-optical modulation, Kerr effect and semiconductor light amplification are fused, and based on device topological structure innovation and unit device optimization, the problems are solved, the on-chip frequency comb performance is significantly improved, and the optical comb laser with excellent starting and tuning performance, high power, large bandwidth and narrow line width is realized.

In a multi-point vibration measurement device, measurement errors caused by mixing of unwanted reflection components generated by various optical elements, such as an optical branching / multiplexing element provided on an optical path through which measurement light irradiated to a measurement surface via an interference optical system passes, into interference light required for multi-point vibration measurement can be eliminated. Therefore, multi-point vibration measurement can be carried out with high precision. In a multipoint vibration measurement device (100), an optical branching / multiplexing head (130) is provided with: an optical branching / multiplexing optical system (131) comprising an optical branching element (131A) connected to an interference optical system (120) to which measurement light (LS) is input from a light source (110), and an optical multiplexing element (131B) connected to the interference optical system (120); a projection optical system (133) that irradiates a plurality of points on a measurement surface (5) of a measurement object with the frequency components of the respective optical combs of the measurement light (LS) split by the light splitting element (131A); and a coupling optical system (132) that inputs, to the projection optical system (133), the frequency components of the respective optical combs included in the measurement light (LS) demultiplexed by the optical demultiplexing element (131A), and that inputs, to the optical multiplexing element (131B), the frequency components of the respective optical combs of the measurement light (LS) reflected and returned by the measurement surface (5).

The invention provides a piezoelectric ceramic-based double-optical-comb-cavity modulated gas measurement system and method, a double-optical-comb output module is utilized to generate a detection optical comb and a reference optical comb which are coherent, 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 piezoelectric ceramic modulation module dynamically adjusts the length of the resonant cavity by applying a periodic voltage signal; and the data acquisition and analysis module demodulates spectral data of the to-be-detected gas through an asynchronous sampling technology based on double optical comb interference signals of the reference optical comb and the detection optical comb. According to the dual-optical-comb-cavity modulated gas measurement system based on the piezoelectric ceramics, the piezoelectric ceramic modulation module is used for dynamically adjusting the length of the resonant cavity according to the detection optical comb and the reference optical comb, dynamic modulation and transient coupling optimization of the cavity length are achieved, and the problems that in the prior art, the dispersion effect of gas can affect optical signal propagation, and the measurement precision is poor are solved. And non-linear modulation occurs in the ring-down process, so that the measurement precision is influenced.

This application discloses an optical communication wavelength meter based on lithium niobate microcavity optical comb-excited rubidium atom two-photon transitions, comprising a microcavity optical comb module, a repetition frequency phase-locked loop (PLL), an initial frequency PLL, a rubidium atom gas cell, and a frequency-stabilized light source. The microcavity optical comb module generates a fundamental frequency optical comb and a frequency-doubled optical comb to directly excite rubidium atom two-photon transitions. The frequency-stabilized light source achieves frequency stabilization through rubidium atom saturation absorption. The repetition frequency PLL adjusts the repetition frequency based on the error signal of the two-photon transition fluorescence intensity. The initial frequency PLL adjusts the initial frequency by feeding back the beat signal between the frequency-doubled optical comb and the frequency-stabilized light source. The two PLLs stabilize the microcavity optical comb to two sets of transition energy levels, achieving frequency locking between the repetition frequency and the initial frequency. The optical communication wavelength meter based on lithium niobate microcavity optical comb-excited rubidium atom two-photon transitions provided in this application avoids the cross-modulation effect in the joint adjustment mechanism of pump wavelength and pump power, reducing the size of the optical communication wavelength meter.

The application discloses an engine rotor multi-parameter measurement system and method, and the system comprises a first optical comb, a second optical comb, a polarization maintaining optical fiber amplifier, a polarization maintaining optical fiber beam splitter, an integrated polarization maintaining optical fiber ring, an integrated polarization maintaining optical fiber beam combiner, a plurality of high-temperature-resistant optical fiber probes, a high-speed photoelectric detector and a data acquisition and processing system; the pulse repetition frequency of the first optical comb is greater than that of the second optical comb, and the two have a high repetition frequency difference; the plurality of high-temperature-resistant optical fiber probes respectively generate reference light pulses and measurement light pulses; the scanning light pulses emitted by the second optical comb respectively interfere with the plurality of reference light pulses and the plurality of measurement light pulses to generate double-comb interference reference signals and double-comb interference measurement signals; through processing of the reference signals and the measurement signals of each channel, the engine rotor speed, the blade tip clearance, the blade tip timing and the blade vibration parameters are obtained. The application has the advantages of high measurement speed, high measurement accuracy and multi-parameter synchronous measurement.

This invention discloses a digital holographic 3D reconstruction system and method based on a single-cavity dual-optical comb, belonging to the field of digital holographic 3D measurement technology. The invention includes: a single-cavity dual-optical comb, a coarse wavelength division multiplexer, a first fiber amplifier, a second fiber amplifier, a first fiber filter, a second fiber filter, a first fiber beam expander, a concave mirror, a second fiber beam expander, a beam splitter, an image sensor, and a computer. The single-cavity dual-optical comb emits two pulses, which are split, amplified, and filtered. The measurement light and the reference light produce interference fringes, forming a hologram. This invention uses a single-cavity dual-optical comb as a light source to achieve the separation of the zero-order image, twin image, and target re-phenomenon in coaxial holography, improving the quality of holographic imaging and facilitating engineering implementation. Based on multi-wavelength heterodyne technology, combined with the wide spectral bandwidth and high temporal coherence of the optical comb, this invention suppresses the influence of noise, enabling the measurement of large-size objects and expanding the application scenarios of digital holography.

A purpose of the present invention is to provide an optical comb generation device capable of obtaining an absolute distance result with high accuracy by reducing a phase offset by a signal transmission path of an object other than an object to be measured, for example in an optical comb distance meter for measuring a distance from a time difference between an interference signal of a measuring light and an interference signal of a reference light. A drive control unit controls to output M (M is an integer of two or more) types of optical combs with mutually different modulation frequencies in which N (N is an integer of three or more) types of modulation frequencies are switched cyclically, by respectively modulating a phase or an intensity periodically, from M optical comb generators, by supplying driving signals to the M optical comb generators comprised in an optical comb generation unit.