146results about How to "Strong ability to resist environmental interference" patented technology

The invention discloses a fire scene multi-parameter laser wavelength modulation spectrum detection method and a device thereof, wherein, fire smoke products are treated through a smoke pre-treatment device and then pumped into a white cell through an air extracting pump; a multi-channel laser controller scans and modulates the wavelengths of a plurality of DFB lasers according to the time-sharing and multiplexing working mode, and all waves of laser share an optical fiber and are outputted sequentially through a wave combiner, then are aligned by a fiber collimator and sent to the white cell to detect the fire smoke products; a photoelectric detector converts light intensity signals of laser repeatedly reflected and absorbed by the white cell into electrical signals which are sent to two phase-locking magnifier modules for frequency selecting magnification so as to obtain a fundamental frequency component and a second harmonic component; a multi-channel data acquisition card converts output voltage signals of the phase-locking magnifiers into digital signals which are sent to a micro-computer for real-time data processing, so that the fire scene multi-parameter information containing the oxygen concentration of the fire scene, concentrations of various toxic gases and smoke concentration is obtained. The detection method and device can realize real-time on-line monitoring to fire scene multi-parameters, and have the advantages of being real-time, multi-component and highly sensitive, good selectivity of gas, high reliability and strong environmental disturbance resistance ability.

The invention discloses a vehicle multiparameter identification method based on a multitask convolution nerve network. The method comprises the following steps of designing and training of a convolution nerve network structure; and vehicle parameter identification based on the convolution nerve network. In the invention, through the convolution nerve network, original data is converted into an abstract high-level expression through a simple and nonlinear model. Therefore, in the convolution nerve network, a recessive character reflecting an essence of an object to be identified can be learned from a lot of training samples. Compared to a shallow learning classifier, by using the method, high expandability is possessed, identification of various kinds of objects in a traffic environment is satisfied and identification precision is high. When being applied to the complex traffic environment, the method has a high anti-environment interference capability. In the invention, the convolution nerve network is applied to multiparameter identification of a vehicle; the trained convolution nerve network is used to identify a type characteristic, pose information and a vehicle light state of the vehicle in an image so that predictable performance of a potential vehicle behavior is enhanced.

Disclosed are a method and a system for in frequency domain optical coherent tomography imaging. The method employs sine phase modulation to recreate complex amplitude of the coherent frequency interference signal; and then performs inverse Fourier transform to the complex amplitude to get the tomographic images of the tested objects and eliminate the complex conjugate image, direct current background and self-coherent noise three spurious images, which enlarges the imaging depth of frequency domain optical coherent tomography imaging is two times larger than the original depth and realizes full depth finding of frequency domain optical coherent tomography imaging.

The invention discloses an integrated type ecological floating bed and the water body ecological system repairing technology thereof. A physical space of the integrated type ecological floating bed is formed by constructing a floating bed, a sinking bed, a buoyancy adjusting bottle, a lifting chain and an ecological barricading net, and integrates ecological components such as indigenous emergent aquatic plants, submerged plants, attached aquatic plants, fishes, snails and biochemical zeolite. The ecological behaviors of the ecological components are in linear cause and effect relation. The ecological components and organisms in the physical space form a semi-enclosed ecological subsystem with integral completeness. The upper line and the water body ecological system to be repaired are strong in coupling capability, and ecological factors in the lower line can exist stably. The damaged water body ecological system sufferring from one or a plurality of types of pollutions including water body eutrophication, heavy metal pollution, organic pollution and the like can be repaired by building pioneer communities and utilizing self-cleaning capability of the ecological system, pollution is removed, integral restoration or rebuilding of the damaged water body ecological system is promoted, simultaneously environment is beautified, and ecological deterioration of a healthy water body can be prevented.

The invention relates to parallel complex frequency domain optical coherence tomography imaging method and system, wherein the method comprises the following steps of: on the basis of the parallel complex frequency domain optical coherence tomography imaging method, replacing a reference plane reflector of an interference reference arm with an inclined reflection grating, and enabling the first-level diffraction light of incident reference light to reversely return along an original incident light path, thereby leading linear space phase modulation in a two-dimensional frequency domain interference strip along the direction of parallel detection, which is obtained by a two-dimensional photoelectric detector, i.e. leading a spatial carrier in the two-dimensional frequency domain interference strip; then carrying out Fourier transformation on the two-dimensional frequency domain interference strip containing the spatial carrier along the direction of parallel detection, next obtaining a two-dimensional complex frequency domain interference strip sequentially through the processes of filtration trough a frequency domain filter window, coordinate transformation and the Fourier transformation along a frequency spectrum direction, and finally obtaining a chromatogram of an object to be measured through the Fourier transformation along a light frequency direction. The invention has simple structure and high imaging speed, and the chromatogram of the object to be measured can be obtained by only needing exposure for one time.

The invention relates to a method for measuring a liquid phase diffusion coefficient, and an apparatus thereof, and belongs to a method for measuring a diffusion coefficient of a liquid by adopting yellow light LED as a light source based on a capillary imaging method. According to the present invention, a transparent capillary is adopted to construct a liquid phase diffusion cell; the specific refractive index spatial resolution measurement capability of the capillary imaging method is adopted to directly observe and record the diffusion regularity of the thin layers of the diffusion medium in the capability, wherein the thin layers of the diffusion medium have the same refractive index; the liquid phase diffusion coefficient is calculated based on the Fick second law. With the present invention, the diffusion coefficient between glycerol and purified water is measured at a room temperature of 25 DEG C, with comparing the diffusion coefficient 0.720*10<-5> cm<2> / s reported by the literature of the traditional holographic interferometry method with the diffusion coefficient 0.715*10<-5> cm<2> / s measured by the method of the present invention, the relative error is 0.69%; the capillary is adopted to construct the liquid phase diffusion cell, such that the amount of the required sample is less, the measurement speed is rapid, the anti-interference capability is strong and the system stability is good.

The invention belongs to the technical field of mechanical environmental test, particularly relates to a triaxial mechanical decoupling device and a vibration testing system, and provides a device for connecting a triaxial simultaneous excitation work bench and a testing system. The triaxial mechanical decoupling device is characterized by comprising a work bench (1) and spherical hydrostatic bearings (4), the work bench (1) is in the shape of a metal plate, two mutually perpendicular mounting faces which are perpendicular to the upper end face and the lower end face of the work bench are arranged on the lateral side of the work bench (1), the spherical hydrostatic bearings (4) are respectively mounted on the lower end face (3) of the work bench, an X-directional side (7) of the work bench and a Y-directional side (2) of the work bench, and the other side of each spherical hydrostatic bearing (4) is connected with a vibration generator. Triaxial composite vibration testing of a workpiece can be achieved by using the corresponding triaxial work bench and the spherical hydrostatic bearings. By means of the triaxial mechanical decoupling device, the workbench can move only in the Z-direction, the X-direction or the Y-direction, so that triaxial translation of the work bench is realized.

The invention discloses a modulation type laser interference method and device for measuring an air refractive index. The method includes the steps that a dual-frequency laser outputs orthogonal linearly polarized lights with wavelengths of lambada 1 and lambada 2 respectively, the lights are emitted to a michelson interferometer formed by a spectroscope, a referential cube-corner prism and a measuring cube-corner prism, and respective interference signals are formed and received by two detectors after light split of the spectroscope and a polarizing beam splitter; and a quartz vacuum cavity is placed in a measuring optical path and is parallel with the light transmission direction, a synthetic wavelength is measured through moving the referential cube-corner prism to detect the phase difference change 2 pi of the interference signals of lambada 1 and lambada 2, motion of the measuring cube-corner prism is modulated through moving a piezoelectric ceramic driver, phase differences delta phi 1 and delta phi 2 of the interference signals of lambada 1 and lambada 2 when the quartz vacuum cavity is pumped into vacuum and when air is introduced in are measured, and the air refractive index n can be measured according to the length of the vacuum cavity L, the synthetic wavelength lambada S, and the phase difference variation (delta phi 2-delta phi 1). The method and the device have the advantages that the measuring accuracy reaches above 10<-9>, the environmental disturbance resistant capacity is high, and the like, and can be applied to the technical fields of precision measurement, laser interferometers, and the like.

The invention provides a bridge deflection detection system and method based on the digital image processing technology. The bridge deflection detection system and method based on the digital image processing technology are used for non-contact measurement of bridge deflection. The bridge deflection detection system based on the digital image processing technology comprises cooperative targets, anoptical filter, an optical lens, a camera, an environmental disturbance monitoring device, an image processing system and a display and control device. According to the bridge deflection detection system based on the digital image processing technology, the cooperative targets are adopted to be fixed to the position where the deflection of a bridge needs to be tested; images of a highlighted LEDon the cooperative targets are captured through the optical lens and the camera; the images of the targets are processed by using an image processing system; the deflection of the bridge is calculatedbased on the information provided by the environmental disturbance monitoring device; and the display and control device is used for guiding the measurement operation and displaying deflection data.The digital image processing technology is adopted in the bridge deflection detection system based on the digital image processing technology, and the bridge deflection detection system based on the digital image processing technology has the characteristics of non-contact measurement, simple operation, wide field adaptation range, high measurement precision, strong environmental interference resistance, multi-point simultaneous measurement and the like.

The invention discloses a phase-shifted-signal-modulation-based fiber interference type sending modulation and demodulation method and device. The device is composed of a laser light source, an isolator, a phase modulator, a 2*2 type coupler, a reference arm, a signal arm, a Faraday polariscope, a signal generator, a photoelectric converter, a data acquisition module, a data processing module and a micro-vibration table. On the basis of high-speed pulse phase modulation on the laser light source, multi-path phase shift signal generation is realized at the output terminal of the fiber sensor; and with a demodulation method of a multi-path phase shift algorithm, vibration phase demodulation of the fiber sensor is realized. The modulation and demodulation method has advantages of simple light path, simple demodulation circuit, good real-time performance, high precision, wide dynamic range and strong anti-environmental interference ability.

The invention provides a spacecraft flying-around approach motion simulator which comprises a testing platform, a target spacecraft motion simulating device and a tracking spacecraft motion simulating device. The spacecraft flying-around approach motion simulator has the advantages that vivid simulation of the respective absolution attitude motion and the relative position motion of a tracking spacecraft and a target spacecraft during orbital flying-around approach, and the defect that an existing linear guide rail type spacecraft motion simulator cannot vividly simulating the orbital flying-around approach of the tracking spacecraft and the target spacecraft is overcome. Compared with an air floatation type spacecraft motion simulator, the spacecraft flying-around approach motion simulator is simple in preparation, high in environment interference resistance, controllable in simulation time, capable of precisely restoring the simulation process, and the like.

The invention discloses a wavelength measurement method and device based on a laser synthesized wavelength interference principle. An output beam of a reference laser device and an output beam of a laser device to be measured are modulated into orthogonal linearly polarized light which is emitted to a laser synthesized wavelength interferometer to form an interference signal of the reference laser device and an interference signal of the laser device to be measured; when a first pyramid prism of the interferometer moves, a phase difference change 2pi of the two interference signals corresponds to the displacement of the first pyramid prism when the first pyramid prism shifts by a half of a synthesized wavelength lambada S formed by a reference laser wavelength lambada R and a laser wavelength to be measured lambada U; when the lambada S is small, the position where the two interference signals pass by a zero point simultaneously for twice is detected to obtain the value of the lambada S; when the lambada S is large, a second pyramid prism is moved first, the position where the two interference signals pass by the zero point simultaneously for twice is detected, and then the value of the lambada S is obtained in combination with the corresponding relation between displacement of the second pyramid prism and the displacement of the first pyramid prism; lastly, the value of the laser wavelength to be measured is obtained according to the relation between the lambada U and the lambada S and the relation between the lambada R and the lambada S. The wavelength measurement method and device based on the laser synthesized wavelength interference principle are wide in laser wavelength measurement range, strong in resistance to environmental disturbance, and high in wavelength measurement accuracy.

The invention discloses a precise landing control system and method based on multi-information fusion. The system comprises: a ground end module used as a UAV accurate landing target point to transmitan infrared image to the sky to be identified by a sky end module; and the sky end module configured to acquire and identify the infrared image transmitted by the ground end module, calculate the relative position of the ground end module, detect the ground relative height, perform data fusion on a visual module, a millimeter wave radar, and the flight control information of a UAV system acquiredin real time, and send a UAV navigation control signal. The method is implemented based on the above system. The system has a long detection distance, high detection precision and a good anti-interference ability.

The invention relates to a fiber Sagner loop dynamic weighing sensor. In the sensor, a tail fiber of a light source module is connected with a first port of a fiber circulator; a second port of the fiber circulator is connected with a first port of a fiber coupler; a third port and a fourth port of the fiber coupler are connected to form a loop circuit by fibers; a fiber polarization controller, a fiber protection and enhancement sensing head and a piezoceramics actuator are connected in series to the loop circuit; a third port of the fiber circulator is connected with an input terminal of a first photodetection unit; a second port of the fiber coupler is connected with an input terminal of a second photodetection unit; an output terminal of the first photodetection unit is connected with a data acquisition card; an output terminal of the second photodetection unit is connected with the data acquisition card; the data acquisition card is connected with an input terminal of the piezoceramics actuator to form a feedback loop and connected with a signal processing and displaying system. The fiber Sagner loop dynamic weighing sensor has the characteristics of strong environmental intrusion resisting capacity, high measuring precision and accuracy and wide measuring scope.

The invention discloses a laser mark automatic tracking extensometer control method based on uncalibrated visual servo. An image Jacobian matrix on-line identification method is adopted, the mapping relation between the actual distance between a laser mark and a sample mark, namely, the tracking displacement of the laser mark and image space tracking displacement is built, a controlled quantity is calculated by identifying the pixel distance difference between a Jacobian matrix and the central points of the two marks through a Karman filter, a servo motor is controlled to drive a pentaprism to rotate, the automatic tracking of the laser mark on the sample mark is achieved, and the laser mark displacement in the extending process is a sample deformation quantity. The method not only avoids the camera calibration step of an existing video extensometer and measuring errors introduced from the step, but also achieves the precise whole-process tracking of the laser mark on the sample mark, and is strong in environmental disturbance resistance capacity and high in tracking precision.

The invention discloses a visual navigation method based on fast feature point extraction and mesh triangle constraint, which comprises the following steps: acquiring continuous video frame sequence images, extracting feature points in adjacent two frame images; meshing the extracted two adjacent frames of images; a 6-dimensional shape descriptor and a 32-dimensional region descriptor being constructed for each triangle, and a feature vector composed of 38-dimensional mixed descriptors of each triangle being obtained; matching the eigenvectors of the triangles corresponding to the mesh division, selecting the feature points with remarkable characteristics by the center point clustering method, eliminating the mismatched feature points, and eliminating the motion feature points by the polargeometry constraint, so as to obtain the effective and usable feature point pairs; completing the final solution of the motion model, and obtaining the position results of visual navigation solution.The invention provides a solution for robot vision navigation and positioning under indoor environment, and has the advantages of fast feature point extraction speed and high matching rate.

The present invention provides an optical fiber interferometer arrangement method of a region anti-intrusion system based on an optical fiber interferometer, wherein one or more defense regions are arranged at the boundary of a protection region of the optical fiber interferometer according to the size of the protection region and a requirement of information precision of an intrusion alarming position, and at least one integrated cycle is formed for the protection region; the plurality of defense regions which are connected in series or parallel form one integrated cycle for the protection region; the light of a light source is transmitted to a light path adapter via a transmission light path, then divided into a plurality of paths corresponding to the defense regions by the light path adapter; one or more defense lines parallel to the boundary are arranged in each of the defense regions, and the plurality of defense lines are arranged at intervals in a longitudinal direction, and each defense line is composed of one path of optical fiber interferometer; the phase difference of the light signal transmitted in two arms of the optical fiber interferometers of each defense region is detected so as to distinguish the characteristic of the doubtful interference events in the boundary of the protection region; when the signal characteristic satisfies the intrusion characteristic mode, the system determines the position of the vibration signal and alarms.

A serially connected optical switch based photon delay structure comprises a plurality of optical switches and multiple sections of single mode waveguides, wherein one input end of a first optical switch is connected with an input optical fiber, and the other input end of the first optical switch is idle; two output end of the first optical switch are connected with two input ends of a second optical switch respectively through two sections of single mode waveguides; other optical switches are sequentially connected in series according to the connection mode of the first optical switch and the second optical switch; one output end of an Nth optical switch is connected with an output optical fiber, and the other output end of the Nth optical switch is idle; and every two optical switches are connected through a first single mode waveguide and a second single mode waveguide, and the first single mode waveguide is longer than the second single mode waveguide. The serially connected optical switch based photon delay structure has the benefits as follows: the serially connected optical switch based photon delay structure has the advantages of high tuning speed, working stabilization and controllability and realizes mass production by virtue of a mature CMOS (complementary metal oxide semiconductor) technology; and besides, a numerical-control integrated photon delay device is integrated on an SOI (silicon on insulator) silicon chip, the size is small, and the integration level is high.

The invention discloses a fiber interferometer-based area anti-intrusion method, which comprises the following steps of: arranging one or more defense areas on the boundary of a protected area by a fiber interferometer according to the size of the protected area and different requirements on information accuracy of an intrusion alarm device, forming at least one complete enclosure for the protected area, and forming a complete enclosure for the protected area by connecting the plurality of defense areas in series or in parallel; making the light emitted from a light source pass through a transmission light path to reach a light path adapter, splitting beams into a plurality of paths by the light path adapter to correspond to the plurality of defense areas respectively; forming one or moredefense lines parallel to the boundary in each defense area, wherein the plurality of defense lines are separated at intervals on depth, and each defense line consists of a path of fiber interferometer; and detecting the phase difference of optical signals transmitted in two arms of the fiber interferometer in each defense area, discriminating the characteristics of suspicious disturbance events on the boundary of the protected area, judging the position of a vibration signal by the system when the signal characteristic accords with an intrusion behavior characteristic mode and alarming by the system.

The invention provides a detection reagent and a quantitative detection method of human serum albumin and belongs to the technical field of fine chemical engineering. Based on a combining attribute of albumin and small molecules, the specific principle of the method is that HCAB can be specifically combined with the albumin, a charge transferring phenomenon in HCAB twisting molecules is inhibited and non-radiation transition is reduced, so that fluorescent light is recovered and quantitative detection of the albumin is realized. After the human serum albumin is excited under a physiological pH value condition (an excitation wavelength lambdaex is equal to 424nm), a stable fluorescent signal (an emission wavelength lambdaem is equal to 526nm) is generated. The fluorescent value intensity is in direct proportion to the concentration of the albumin; and according to a detected fluorescent value, the content of the albumin in a biological sample can be calculated. The method can be used for determining absolute content of the albumin in a plurality of types of biological samples including blood serum, urine and the like; and meanwhile, the method also has the advantages of high sensitivity, high accuracy, high environment interference resisting capability, easiness of carrying out high-flux detection and the like.

The invention discloses a heliostat reflecting facula offset correction method and belongs to the technical field of solar tower type thermal generating. According to the heliostat reflecting facula offset correction method, a heliostat reflecting facula offset correction device and a heliostat tracking offset database of the heliostat reflecting facula offset correction device are used for carrying out heliostat reflecting facula offset correction. The azimuth angle and the angle of pitch of a heliostat are adjusted and corrected by means of data on the ideal azimuth angle, the ideal angle of pitch, azimuth angle correction and angle of pitch correction of the heliostat in a heliostat tracking offset database based on relevant characteristics of tracking offset of the heliostat and the angle of pitch and the azimuth angle of the heliostat so as to achieve heliostat reflecting facula offset correction. The correction device and the heliostat tracking offset database of the correction device are low in cost and capable of resisting interference by ambient light and procedures of correcting heliostat reflecting facula offset are simple. The requirement for industrial on-spot application can be met. The heliostat reflecting facula offset correction method is suitable for heliostat reflecting facula offset correction of a heliostat tracking system of a tower type solar thermal generating station.

The invention belongs to the technical field of micro-spectral imaging detection and relates to a method and device for testing a spectral pupil laser differential confocal CARS micro-spectrum. The core thought is as follows: Rayleigh light and CARS light loaded with tested sample spectral characteristics are excited by double lasers as a light source; and nondestructive separation is carried out on the Rayleigh light and the CARS light by using a dichroic optical system, wherein the Rayleigh light is subjected to geometrical detection and positioning, and the CARS light is subjected to spectrum detection. By using the characteristic that a zero crossing point of the spectral pupil laser differential confocal curve accurately corresponds to a focus position, the focus position of an excitation beam is accurately captured and positioned, and high-precision geometrical detection and high-spatial-resolution spectrum detection are achieved to form the method and device capable of achieving high-spatial-resolution spectrum detection of a sample micro-region. Through combining a CARS microscopical technique, the excited Raman scattering light loaded with sample information is shorter than a traditional spontaneous Raman effect in time, and the sample can be quickly subjected to nondestructive detection. The method and the device have the advantages of accurate positioning, high spatial resolution, nondestructive detection and high spectrum detection sensitivity, and a new way is provided for micro-region spectrum detection and geometrical measurement.

The invention discloses a human eye sight line detection method and device based on the photogrammetry technology. The method comprises a step of setting a stereo target to calibrate an image acquisition unit and obtaining internal parameters and / or external parameters of the image acquisition unit, continuously acquiring human face images in the time sequence by using the image acquisition unit and processing each of the human face images and obtaining iris center pixel coordinates of human eyes, carrying out three-dimensional reconstruction based on the internal parameters and / or external parameters of the image acquisition unit and the iris center pixel coordinates to obtain human eye three-dimensional coordinates and saving the human eye three-dimensional coordinates according to the time sequence, and reconstructing a human eye motion trajectory according to the human eye three-dimensional coordinates saved in the time sequence. The human eye sight line detection method and devicebased on the photogrammetry technology provided by the invention can be applied to provide data information for visual fatigue assessment, and hidden dangers caused by visual fatigue on human healthand traffic safety are avoided.

The present invention discloses linear polarization output all-fiber pulse dual-cavity lasers. The laser comprises a pump source, a polarization maintain fiber beam combiner, a first polarization maintain gain fiber, a second polarization maintain gain fiber, a first reflective polarization maintain fiber Bragg grating, a second reflective polarization maintain fiber Bragg grating, a third reflective polarization maintain fiber Bragg grating, and a fourth reflective polarization maintain fiber Bragg grating. Or, the laser comprises a pump source, a polarization maintain fiber wavelength division multiplexer, a first polarization maintain gain fiber, a second polarization maintain gain fiber, a first reflective polarization maintain fiber Bragg grating, a second reflective polarization maintain fiber Bragg grating, a third reflective polarization maintain fiber Bragg grating, and a polarization maintain fiber circulator. The laser has a dual-resonance cavity crossing modulation structure, uses a doped fiber as a gain medium and a saturated absorber, and is an all-fiber polarization maintain laser realized based on the novel polarization technology. The laser is simple in design, has a compact structure, can output linear polarization pulse laser efficiently and stably, and has characteristics of high stability, high efficiency and high energy.

A three-dimensional detection device based on binocular vision comprises a binocular stereo camera, a line laser emitter, a glass panel, an image processor and a central controller, and the line laseremitter controls emission of line laser while the binocular stereo camera is started; the central controller comprises a control module, a matching module and a coordinate calculation module. After an image is preprocessed by the image processor, the central control module matches the corrected image to obtain a laser imaging matching point pair, and the coordinate calculation module calculates to obtain three-dimensional information of an object to be measured according to parallax of left and right views after light penetrates through glass or a transparent object. By utilizing the characteristic that light is transmitted in the transparent object, the transmitted light is received in a binocular multi-angle mode, three-dimensional curved surface three-dimensional information of the transparent object can be accurately and rapidly obtained, the shape, flatness, curvature change and surface quality of the glass panel are rapidly detected, the measurement precision is high, the speedis high, and the cost effectiveness is high.

The invention discloses a composite material ultrasonic guided wave structure health monitoring method in a variable temperature environment. The method comprises the steps: constructing a reference coefficient set of a structure health monitoring network through calculating a difference index between reference signals in a reference signal set; and performing reference screening and calculating adamage index according to the temperature information of the signals acquired in real time, solving a damage proportionality coefficient under each propagation path in combination with the referencecoefficient, importing the damage proportionality coefficient into a detection network to perform actual damage path screening, and finally outputting the position of the damage in combination with adamage positioning imaging algorithm. The composite material ultrasonic monitoring method provided by the invention can effectively remove the influence of the anisotropism of the composite material on ultrasonic propagation, can effectively eliminate the interference of environmental factors on ultrasonic signals, and can quickly realize the accurate positioning of damage.

The invention discloses a modulation and demodulation method and device for an optical fiber grating sensor based on phase shift signal modulation. The modulation and demodulation device comprises a laser source, an isolator, an optical switch, a phase modulator, a circulator, an optical fiber grating group, a signal generator, a photoelectric converter, a data acquisition module and a data processing module, and is characterized in that the laser source is modulated by using the optical switch so as to generate a pulse beam, then high-speed pulse phase modulation is performed on the pulse beam by using the phase modulator, the pulse beam is interfered in the circulator, multipath phase shift signals are generated and outputted via a third port, and vibration phase demodulation for an optical fiber sensor is realized by being cooperated with a demodulation method of a multipath phase shift algorithm. The modulation and demodulation method is simple in optical path, capable of forming a plurality of sensing modules conveniently, low in modulation requirement, simple in demodulation circuit, high in real-time performance and precision, wide in dynamic range and high in environmental interference resisting ability.

The invention relates to an in-cavity self-adaptive optical beam purification system and a method. The self-adaptive optical beam purification system consists of a parallel light source, a deformable mirror, a Hartmann sensor, a data acquisition and control computer, a high-voltage amplifier, a spectroscope, a focusing lens, a beam quality diagnosis camera and a laser device. During beam purification, the prior surface shape of the deformable mirror is preset at first via the Hartmann sensor, and then the beam is purified in a random optimization control method. By adopting the method, prior data can be utilized effectively, the time for purification of the beam in the cavity can be greatly reduced, and the control stability of the in-cavity beam purification system can be improved.

The invention discloses a method for measuring air refractive index fluctuation by laser synthetic wavelength interferometry. In a laser synthetic wavelength interferometer composed of a double-frequency laser, a spectroscope, two polarizing beam splitters, a reference pyramid prism and a measuring pyramid prism, the measuring pyramid prism of the interferometer is fixed, and then the optical path between a first polarizing beam splitter of a measuring arm and the measuring pyramid prism forms an air refractive index fluctuation sensing chamber; the light path change of the interferometer measuring arm caused by the air refractive index fluctuation in the chamber is equivalent to a minimal measured displacement; with the displacement measuring principle of laser synthetic wavelength interferometry, the measurement of the minimal measured displacement is converted into the measurement of the reference pyramid prism moving displacement (in millimeter or micron), which realizes high-precision measurement of air refractive index fluctuation. The method of the invention realizes a measuring precision of air refractive index fluctuation of up to 10-11, and is applicable to technical fields of air refractive index measurement, precise length measurement, and the like.

The invention discloses a high-precision laser modulation interference air refractive index absolute measurement device and a high-precision laser modulation interference air refractive index absolutemeasurement method. A laser output by a single-frequency laser is split into two parallel light beams by a lateral displacement spectroscope after being subjected to optical isolation and sinusoidalphase modulation, and the two parallel light beams are emitted to a sinusoidal phase modulation interferometer to obtain measurement and compensation interference signals which are received by two detectors; a length-variable vacuum cavity is placed in a measurement light path of the sinusoidal phase modulation interferometer and is parallel to a light propagation direction, and the two parallel light beams respectively pass through an internal vacuum light path and an external air light path of the vacuum cavity. During measurement, a linear displacement workbench drives a moving light-transmitting window to move for a distance, the phase variation of two paths of interference signals is calculated in real time, and the air refractive index is solved. The measurement device and method arehigh in measurement precision and high in environmental interference resistance, and can be widely applied to the technical field of laser interference precision measurement.