39 results about "Light bullet" patented technology

The invention relates to the field of image processing, and discloses a wind turbine generator blade surface defect intelligent detection method based on image processing, which is used for improving the accuracy of wind turbine generator blade surface defect detection. Comprising the steps that pulse laser thermal excitation infrared thermal imaging and a multi-angle polarization light source array polarization imaging technology are fused, a bimodal data set is constructed, and thermal anomaly features of a dynamic thermal image sequence are extracted; and photoelastic stress characteristics are obtained through phase analysis and local energy filtering. Generating a fusion defect indication diagram by utilizing heat conduction blocking and stress concentration space coincidence strengthening mechanism fusion features, obtaining a defect probability distribution diagram, calculating a predicted risk value, matching a maintenance strategy library according to the risk value, outputting a maintenance scheme code, and generating a three-dimensional maintenance guide diagram. According to the invention, intelligent and accurate detection and maintenance guidance of blade surface defects are realized, and the comprehensiveness and accuracy of defect detection are improved.

The invention relates to the technical field of photoelectric detection, and provides a surfactant adsorption behavior detection system based on an oblique incident light reflection difference technology, which comprises a laser, a polarizer, a photoelastic modulator, a phase shifter, a first lens, a sample table, a second lens, an analyzer, a photoelectric detector, a first lock-in amplifier, a second lock-in amplifier and a computer, the laser emits probe light which is changed into p polarized light through the polarizer; the light is modulated into p polarized light and s polarized light by the photoelastic modulator; the p polarized light and the s polarized light are emitted alternately, and a phase shifter generates a fixed phase difference between the p polarized component and the s polarized component; the light is focused by the first lens and obliquely enters the surface of a sample on the sample table; the laser reflected from the surface of the sample passes through the second lens, then enters the polarization analyzer, is received by the photoelectric detector and is converted into an electric signal; and the fundamental frequency signal and the frequency multiplication signal are recorded by the computer. According to the method, the adsorption process, the adsorption state and other properties of the surfactant can be analyzed.

The invention belongs to the technical field of optical measurement, and particularly discloses double-channel photoelastic modulation ellipsometry equipment and method. The device is constructed based on the ellipsometry principle of photoelastic modulation and comprises a light source, a collimating lens, a first polaroid, a second polaroid, a first photoelastic modulator, a sample table, a second photoelastic modulator, a beam splitter and a plurality of signal collectors. According to the device, the photoelastic modulator utilizes the piezoelectric effect and stress birefringence principle, modulation of signals is achieved by applying an alternating electric field, the modulation method does not need any moving part, and measurement can be completed stably at a high speed. Moreover, through the arrangement of multi-channel detection in the equipment, the equipment can obtain information of multiple wavelengths of the sample at the same time, and the thickness and optical parameters of the film sample are calculated in sequence.

The invention relates to a precision optical measuring instrument calibration technology, and discloses a parameter calibration method and system for a four-photoelastic modulator type Mueller matrix polarization system, and the method comprises the steps: carrying out a polarization experiment; introducing an analysis arm base vector and a polarization arm base vector containing dynamic parameters, and establishing a calculation model of the light intensity signals, the base vectors and a light intensity projection matrix; through a polarization experiment and a calculation model, dynamic parameters in base vectors of a polarization detection arm and a polarization starting arm are calibrated by using a nonlinear regression method, and the dynamic parameters comprise the peak retardation, the modulation frequency and the initial phase of the photoelastic modulator. Furthermore, a matrix containing static parameters of the system is obtained through a characteristic value calibration method and is directly used for measurement, and the static parameters comprise the azimuth angle of the polarization element and the static delay amount of the photoelastic modulator. According to the method, the base vector is introduced, the light intensity is detected through nonlinear regression projection, the calibration of dynamic parameters is realized, then the static parameters are calibrated by using the characteristic values, the operation is simple and convenient, and the calibration precision is high.

Variable-angle ellipsometry is performed using a high speed polarization state modulator, a photodetector, and a digital micromirror device or spinning disk to encode the angle of incidence of light with a high sampling rate in a time domain or frequency domain. A variable-angle ellipsometer uses a high speed, axially stationary polarization state modulator, such as a photoelastic modulator, and a high speed detector, such as a photodiode, for high speed data acquisition. To acquire data at a plurality of incident angles, a lens is used to generate a large incident angle distribution along an optical axis that is at an oblique angle of incidence and discrete or combinations of incident angles of light are selected in a sequence in the time domain or modulated over a plurality of incident angles in the frequency domain.

The utility model belongs to the technical field of glass stress measurement devices, and particularly relates to a photoelastic scattering stress measurement and analysis device which comprises a laser, an adjustable diaphragm mechanism, a polarization mechanism, a photoelastic modulation mechanism, a prism and a shooting mechanism. The imaging means captures a plurality of images of scattered light generated by incidence of the laser light having changed polarization phase difference on the tempered glass at predetermined time intervals, acquires a plurality of images, measures a periodic brightness change in the scattered light using the plurality of images, calculates a phase change in the brightness change, and calculates a phase change in the phase change. And a stress distribution in the depth direction from the surface of the tempered glass and a stress value at each stress layer point of the tempered glass are calculated on the basis of the phase change.

This invention provides a method for measuring dielectric constant based on oblique incidence light reflection difference technology. The probe light emitted by the laser 1 is converted into p-polarized light by the polarizer 2, and then modulated into p-polarized light and s-polarized light by the photoelastic modulator 3. The p-polarized light and s-polarized light are emitted alternately at a frequency of 50 kHz, and after passing through the phase shifter 4, a fixed phase difference is generated. Then, the light is focused by the first lens 5 and obliquely incident on the surface of the sample 6 to be tested, with the incident range between 50° and 60°. The signal light reflected from the surface of the sample 6 to be tested is incident on the analyzer 9 after passing through the second lens 8. The analyzer 9 is used to zero the fundamental frequency signal of the system. The signal light after passing through the analyzer 9 is absorbed by the photodetector 10 and converted into an electrical signal. The electrical signal is demodulated by the first lock-in amplifier 11 and the second lock-in amplifier 12 into a DC signal, a fundamental frequency signal I (Ω), and a harmonic signal I (2Ω). The demodulated signal is acquired and processed by the data acquisition and processing unit 13.

The present invention provides a three-dimensional photoelastic testing device and testing method for pipe sections, which relates to the field of pipe section model tests and includes: a transparent model box for inserting two mutually abutting pipe sections with variable included angles between the axes of the two pipe sections; a loading assembly for applying a force to the pipe sections; a photo-inspection assembly for respectively obtaining the interference fringes of the two pipe sections, the photo-inspection assembly including an outer module, an inner module and a light source, the light source being arranged on one side of the outer module away from the pipe section, the outer module including an outer polarizer and an outer quarter-wave plate, the outer module being semi-cylindrical, the axis of the outer module being parallel to the corresponding pipe section, the inner module including a photosensitive screen, an inner analyzer, an inner quarter-wave plate, an eyepiece and an objective lens, the photosensitive screen, the inner analyzer and the inner quarter-wave plate all being semi-cylindrical; a recording system for obtaining the interference fringes and the magnitude of the loading force. The present application uses a three-dimensional curved photoelastic imaging method to obtain the interference fringes of the pipe section, thereby realizing the analysis of the stress field of the pipe section.

The present invention discloses a fire smoke particle detection device and method based on scattering differential spectrum. The combination of an aerosol generator and an air pump can simulate a smoke environment and adjust the concentration of smoke particles in the environment to maintain the stability of the smoke environment. A xenon lamp is used as a light source to provide a wide-band spectral output. A reflective spectrometer detects the spectral characteristics of light, and a polarizer and a photoelastic modulator are used to convert the light into linearly polarized light, which is then irradiated on smoke particles to generate scattered light in different directions. The polarizer can receive scattered light in different directions through a rotating base and only allows light with a specific polarization angle to be transmitted to the detector, thereby simulating different smoke particle emission conditions and obtaining corresponding scattered photoelectric signals. Finally, a Labview program is used to deduce the matrix elements of the fire smoke particles, and then the type and particle size of the smoke particles are calculated, so that the present invention has good real-time performance and accuracy.

The invention belongs to the technical field of photoelastic modulation, and particularly relates to a high-speed and high-precision four-photoelastic modulation closed-loop control Mueller matrix measuring device and method, a first photoelastic modulator is arranged in the light path direction of a polarizer, a second photoelastic modulator is arranged in the light path direction of the first photoelastic modulator, and a third photoelastic modulator is arranged in the light path direction of the second photoelastic modulator. The Muller matrix sample to be measured is arranged in the light path direction of the second photoelastic modulator, the third photoelastic modulator is arranged in the light path direction of the Muller matrix sample to be measured, the fourth photoelastic modulator is arranged in the light path direction of the third photoelastic modulator, the polarization analyzer is arranged in the light path direction of the fourth photoelastic modulator, and the polarization analyzer is arranged in the light path direction of the second photoelastic modulator. And the detector is arranged in the light path direction of the polarization analyzer. According to the invention, the four photoelastic modulators are adopted for modulation, the phase delay amplitudes of the four photoelastic modulators are obtained in real time through phase locking of different sum frequency and difference frequency signals of the four photoelastic modulators and the amplitude ratio of different frequency signals, and the influence of light intensity fluctuation of a light source is eliminated.

The application provides an experimental device and method for fracture three-dimensional stress interference visualization. The experimental device comprises: a photoelastic experimental mechanism for visualizing a stress field of an experimental sample; a three-way stress loading mechanism arranged at an observation position of the photoelastic experimental mechanism and used for loading three axial stresses on the experimental sample; and a light source direction clamping mechanism comprising two numerical control hydraulic clamping assemblies symmetrically arranged on two sides of a light source direction of the experimental sample, and the two numerical control hydraulic clamping assemblies are matched to maintain stress loading on the experimental sample in the light source direction. The experimental method adopts the experimental device for fracture three-dimensional stress interference visualization. The application has the beneficial effects of enabling indoor experimental research on stress distribution and stress interference of a stratum under three axial stress conditions.

The application discloses a multifunctional stud for bridge vibration monitoring and a monitoring method, which comprises a monitoring end and a transceiving end, the vehicle-approaching surface of the monitoring end is provided with a vehicle warning part, and the vehicle-receding surface is provided with a vibration monitoring part; the vibration monitoring part is provided with a first inner cavity with an open bottom, the vehicle-receding surface light-transmitting glass is arranged on the outer side of the first inner cavity, the inner side of the vehicle-receding surface light-transmitting glass is provided with a polarization device, and the lower part is provided with a photoelastic test buckle; the transceiving end comprises a light source for emitting a monitoring light beam to the vehicle-receding surface light-transmitting glass and a camera device for collecting the emitted light beam; the side surface of the first inner cavity opposite to the vehicle-receding surface light-transmitting glass is provided with a mirror surface sticker, the mirror surface sticker is arranged to reflect the monitoring light beam to the photoelastic test buckle; the bottom of the photoelastic test buckle is coated with a reflective coating, and the reflective coating reflects the monitoring light beam to the mirror surface sticker and the camera device. The multifunctional stud can statistically analyze the stress of each measuring point on the bridge deck, and realize the visualization of the overall state of the bridge vibration.

The invention discloses a vacuum glass heat transfer coefficient measuring method and device, and the method comprises the steps: placing to-be-detected vacuum glass in a vacuum chamber provided with a vacuumizing system and an air pressure detection device, enabling the air pressure detection device to display the air pressure value of the chamber in real time, and forming a uniform polarized light field perpendicular to the placement direction of the glass in the chamber; and during vacuumizing, the light spot is detected on the side, opposite to the light source, of the glass through a polarization analyzing polaroid, the air pressure value P is recorded when the light spot disappears, and then the heat transfer coefficient is calculated according to the air pressure value P. Based on the photoelastic principle, the air pressure in the vacuum glass is determined by observing stress light spot changes, then the heat transfer coefficient is accurately calculated, the method is not affected by the environment temperature, measurement repeatability is good, measurement can be rapidly completed, the measurement efficiency and accuracy are greatly improved, and the method is suitable for popularization and application. And the urgent requirement of the vacuum glass production detection field on accurate measurement of the heat transfer coefficient is effectively met.

The triaxial compression test device based on the photoelastic instrument comprises a light source and an imaging device, a photoelastic instrument main body is arranged between the light source and the imaging device, and the photoelastic instrument main body comprises a front polarization frame and a rear polarization frame which are respectively provided with a front polarizer and a rear polarizer; a test piece loading frame is arranged between the front polarization frame and the rear polarization frame, a downward pressing force application plate is arranged in the test piece loading frame, and a tension sensor is arranged below the downward pressing force application plate. The change of internal stress and a contact force chain of the particles is analyzed by observing the optical performance of the particles, a stress field of the particles is drawn, the rotation angle and the displacement field of the particles can be researched, the micro-mechanical characteristics in the particles are further analyzed, and macro-mechanical information and the micro-mechanical characteristics are combined for analysis; and the property change of the particles in the test process can be better studied.

The present invention discloses a photoelastic modulator calibration system and method, which relates to the technical field of optical measurement instruments. The system includes a laser light source, a polarizer, a photoelastic modulator, an analyzer, a light intensity collector, and a computer. By establishing a simulation model of the time-varying light intensity signal, the present invention optimally fits the first component of the simulated Stokes vector and the actual time-varying light intensity signal, and takes the peak simulation value of the modulation phase delay amount that makes the error between the actual time-varying light intensity signal and the first component meet the requirements as the final calibration value of the peak modulation phase delay amount of the photoelastic modulator, and takes the simulation value of the static phase delay amount that makes the error between the actual time-varying light intensity signal and the simulated time-varying light intensity signal meet the requirements as the final calibration value of the static phase delay amount of the photoelastic modulator, so as to accurately calibrate the peak modulation phase delay amount and the static phase delay amount of the photoelastic modulator.

The invention discloses an optical orbital angular momentum high-speed detector and method for rapid response of left and right circular polarization states. Based on a high-speed polarization modulation technology and an orbital angular momentum detector, information of orbital angular momentum of light is detected at a high speed; compared with a minute-order detection speed based on a traditional detection method, the detection speed of the optical orbital angular momentum is increased to a millisecond order, and meanwhile, the quantum number of the optical orbital angular momentum can be directly distinguished through a circular polarization dependent component of the radial light current extracted by the lock-in amplifier; extra calculation and data processing through a computer are not needed; the photoelastic modulator has a large working wavelength range, so that the method can also be suitable for optical orbital angular momentum detection in a large wavelength range; the method is applied to various optical orbital angular momentum detection application occasions such as infrared imaging, military reconnaissance and focal plane imaging.

The application relates to the technical field of photoelectric detection, and provides a surfactant adsorption behavior detection system based on oblique incidence light reflection difference technology, which comprises a laser, a polarizer, a photoelastic modulator, a phase shifter, a first lens, a sample stage, a second lens, a detector, a photoelectric detector, a first lock-in amplifier, a second lock-in amplifier and a computer; the laser emits detection light; the detection light becomes p-polarized light through the polarizer; the p-polarized light and s-polarized light are modulated by the photoelastic modulator; the p-polarized light and s-polarized light are alternately emitted, and a fixed phase difference is generated between the p-polarized component and the s-polarized component by the phase shifter; the p-polarized light and s-polarized light are focused by the first lens and obliquely incident on the sample surface of the sample stage; the laser reflected from the sample surface is incident into the detector through the second lens, then is received by the photoelectric detector and is converted into an electric signal; and the fundamental frequency signal and the multiple frequency signal are recorded by the computer. The application can analyze the surfactant adsorption process and the adsorption state and other properties.

Variable-angle ellipsometry is performed using a high speed polarization state modulator, a photodetector, and a digital micromirror device or spinning disk to encode the angle of incidence of light with a high sampling rate in a time domain or frequency domain. A variable-angle ellipsometer uses a high speed, axially stationary polarization state modulator, such as a photoelastic modulator, and a high speed detector, such as a photodiode, for high speed data acquisition. To acquire data at a plurality of incident angles, a lens is used to generate a large incident angle distribution along an optical axis that is at an oblique angle of incidence and discrete or combinations of incident angles of light are selected in a sequence in the time domain or modulated over a plurality of incident angles in the frequency domain.

The present application relates to precision optical measuring instrument calibration technology, disclose a kind of four photoelastic modulator type mueller matrix polarization system parameter calibration method and system, the method comprises: conducting polarization experiment;Introducing the detection polarization arm base vector and polarizing arm base vector containing dynamic parameters, establish the calculation model of light intensity signal and these base vectors and light intensity projection matrix;Through polarization experiment and calculation model, the dynamic parameters in detection polarization arm and polarizing arm base vector are calibrated using nonlinear regression method, these dynamic parameters include the peak retardation of photoelastic modulator, modulation frequency and initial phase.Further, the matrix containing system static parameters is obtained by eigenvalue calibration method, directly used for measurement, static parameters include the azimuth angle of polarization element and the static retardation of photoelastic modulator.The method introduces base vector, realizes the calibration of dynamic parameters by detecting light intensity through nonlinear regression projection, then the static parameters are calibrated using eigenvalue, easy to operate, and high calibration accuracy.

Laser processing device (1) with: a pulsed laser oscillator (51) configured to oscillate a pulsed laser beam (LB) at a predetermined repetition frequency; a main polarization beam splitter (53) which is arranged in a laser beam oscillation direction on a downstream side of the pulse laser oscillator (51); a quarter-wavelength plate (54) which is configured to convert a pulsed laser beam (LB) passing through the main polarization beam splitter (53) from P-polarized light into circularly polarized light; a photoelastic modulation element (55) which is configured to modulate a pulsed laser beam passing through the quarter-wavelength plate (54) into a P-polarized pulsed laser beam and an S-polarized pulsed laser beam; a frequency setting device (730a) which is configured to set a modulation frequency by means of the photoelastic modulation element (55); a subpolarization beam splitter (56) configured to split the P-polarized pulsed laser beam and the S-polarized pulsed laser beam, which are modulated by the photoelastic modulation element (55); a first reversing means (6a; 7a; 57a) for reversing the pulsed laser beam diverted from the P-polarized light by the subpolarization beam splitter (56) to cause the pulsed laser beam to move in the reverse direction thereafter along an optical path of a return path of the pulsed laser beam which is slightly inclined with respect to an optical path of a forward path of the pulsed laser beam; a second reversing means (6b; 7b; 57b) for reversing the pulsed laser beam diverted from the S-polarized light by the subpolarization beam splitter (56) to cause the pulsed laser beam to subsequently travel in the reverse direction along an optical path of a return path of the pulsed laser beam which is slightly inclined with respect to an optical path of a forward path of the pulsed laser beam; and a condenser (580; 580a) arranged in paths of the pulsed laser beams reflected by the main polarization beam splitter (53), after the pulsed laser beams inverted by the first inversion means (6a; 7a; 57a) and the second inversion means (6b; 7b; 57b) pass through the quarter-wavelength plate (54), whereupon the pulsed laser beams are converted into S-polarized pulsed laser beams.

The invention discloses a tempered glass curtain wall impurity and defect on-site detection system and detection method, and relates to the technical field of tempered glass defect detection. The problem that when a detection device detects a high glass curtain wall, external wind power easily blows the detection device to shake on the outer wall of the glass curtain wall, and consequently the detection result is not accurate enough is solved. The detection system specifically comprises a polarized light irradiation mechanism for emitting a light source for detection, an image shooting mechanism for observing photoelastic stress spots of the tempered glass curtain wall, a cleaning mechanism for cleaning the outer wall of the tempered glass, and a dust collection mechanism for adsorbing the detection system on the outer wall of the tempered glass curtain wall. The detection system can automatically sweep the surface of the glass curtain wall during detection, meanwhile, dust generated during sweeping is absorbed, the walking stability of the detection system on the outer wall of the glass curtain wall can be improved, and therefore the defect detection accuracy is improved.

A spin-orbit torque (SOT) measuring apparatus includes a photoelastic modulator (PEM) configured to periodically modulate a polarization direction of linearly polarized incident light and emit a periodically modulated light, a first polarization rotator configured to rotate a polarization direction of the periodically modulated light, a voltage generator configured to generate an AC current to a sample to which light with the rotated polarization direction is to be emitted, a prism configured to split light reflected into first light and second light having different polarization directions, a balanced detector configured to output a signal corresponding to an intensity difference between the first light and the second light, a changing circuit configured to change a frequency component to the intensity difference, and an amplitude measurer configured to measure an amplitude of a frequency component corresponding to a modulation frequency of the PEM with the changed frequency component.

To provide an optical repeater and an optical communication system that suppress voltage consumption when an odd number of light sources are provided. An optical repeater according to the present disclosure includes at least n units being an odd number equal to or more than 3, wherein the n units each include an excitation light source, a first optical demultiplexer, a second optical demultiplexer, a first optical multiplexer, and a second optical multiplexer, the first optical demultiplexer demultiplexes excitation light from the excitation light source into 1:n−1, the second optical demultiplexer demultiplexes, into n−1 pieces of excitation light, excitation light demultiplexed by the first optical demultiplexer with a ratio of n−1, the second optical demultiplexer further outputs excitation light demultiplexed to each of the first optical multiplexers belonging to n−1 units other than a unit to which the second optical demultiplexer belongs.

The invention discloses an improved photoelastic coefficient testing method based on a Mach-Zehnder double-beam interference system, belongs to the field of optical measurement, and aims to solve the problems that errors are large and optical path difference components cannot be decoupled due to non-uniform stress in an existing photoelastic coefficient measuring technology. The method comprises the steps that S1, a Mach-Zehnder double-beam interference light path is built, and laser is divided into a test beam and a reference beam after passing through a polaroid; a to-be-tested transparent test piece is arranged in the test light beam; s2, applying uniformly distributed alternating stress to the transparent test piece to be tested through a stress application device; s3, the polarization direction is adjusted to be parallel to and perpendicular to the stress applying direction, the alternating current signal amplitude Vout of the photoelectric detector is collected through a lock-in amplifier, and light intensity change slopes k11 and k12 are calculated; s4, stress optical coefficients pi11 and pi12 are calculated; and S5, photoelastic coefficients p11 and p12 are calculated through matrix operation p = pic.

The invention provides a photoelastic modulator modulation amplitude frequency-response-free calibration device and method, and relates to the technical field of polarization optical detection. As a phase modulation device, the phase modulation amplitude of the photoelastic modulator is influenced by modulation voltage and dispersion, so that accurate calibration must be carried out before the photoelastic modulator is applied to precise optical measurement. A calibration device is formed by a light source, a polarizer, a wave plate, a photoelastic modulator, a photoelastic modulator controller, an analyzer, a detector and a digital lock-in amplifier, first and second frequency multiplication signals are synchronously scanned, zero value points of first and second frequency multiplication components are accurately positioned, phase modulation amplitudes are calibrated by respectively utilizing inverse solution first and second order Bessel functions, and the phase modulation amplitude is calculated. And high-resolution phase modulation amplitude calibration without the influence of the frequency response characteristic in a full calibration interval is obtained in a segmented recombination form. The device and the method have no special numerical value and precision requirements on the azimuth angle of the device and the phase retardation of the wave plate, and have robustness.

The present application provides a dynamic multi-physics field measurement experimental system based on an embedded grating photoelastic model. In the system, a photoelastic model that simultaneously satisfies the requirements of high-speed dynamic photoelastic stress measurement and moire deformation measurement is used to generate time series images through a circularly polarized dark field optical path; an axial load and a dynamic load are applied to the photoelastic model through a vertical loading device and a dynamic loading device in a loading unit, respectively; the vibration signal of the photoelastic model is collected through a vibration sensor in a synchronization unit, and the pulse light source and the image acquisition unit are simultaneously triggered by a synchronization trigger to collect the time series images generated by the circularly polarized dark field optical path. In this way, the time series images generated by the photoelastic model that simultaneously satisfies the requirements of high-speed dynamic photoelastic stress measurement and moire deformation measurement are used to eliminate the mutual interference in the photoelastic and moire measurements, realize the simultaneous measurement of stress field, displacement field, and strain field, and overcome the difficulties in multi-physics field measurement in the prior art.

The utility model discloses a torsion test device based on a photoelastic instrument, which comprises a light source and an imaging device, a photoelastic instrument main body is arranged between the light source and the imaging device, and the photoelastic instrument main body comprises a front polarization frame and a rear polarization frame which are respectively provided with a front polarizer and a rear polarizer. A test piece loading frame is installed between the front polarization frame and the rear polarization frame, a torsion device is arranged in the test piece loading frame and is composed of a torsion sleeve, a driving motor, a rotating shaft, a rotating locking device and a fastening screw rod, the torsion sleeve is rotationally arranged in the horizontal direction of the inner side of the test piece loading frame, and the rotating shaft is rotationally arranged in the horizontal direction of the inner side of the torsion sleeve. The device has the beneficial effects that a torsion test and a photoelastic method are combined, the stress and deformation behaviors of the test piece under the action of a torsion couple are analyzed by observing the optical characteristics of the test piece, and the change condition and stress distribution of the test piece in the damage process are observed.

The invention relates to the technical field of electronic equipment, and provides a head-up display. The head-up display comprises a microcontroller, a photoelastic modulator, an optical coupling area, an optical waveguide, a grating area and a light absorption area. The microcontroller is configured to process pixel shifts of the image. The photoelastic modulator is electrically connected to the microcontroller and is configured to modulate the spatial polarization state of the image to a spatial frequency. The optical coupling region is optically coupled to the photoelastic modulator and is configured to couple the image. The optical waveguide is optically coupled to the optical coupling region and is located between the optical coupling region and the photoelastic modulator. The grating region is located beside the light coupling-in region and directly contacts the optical waveguide, and is configured to couple out the image of the spatial frequency. The light absorption area is arranged around the optical waveguide. Therefore, light (namely stray light) which does not conform to the spatial frequency modulated by the photoelastic modulator can be filtered out by the grating when being coupled out, so that the influence of the stray light on the viewing experience is reduced, only the structured light modulated by the photoelastic modulator is left in the eyes of a user, and the overall viewing experience is clearer.

The present application relates to a kind of achromatic RGB photoelasticity measurement methods based on color polarized camera, which is based on plane polarized light path implementation, in plane polarized light path, first light source and second light source of vertical distribution are sequentially through polarizer, half mirror, the tested piece and the color polarized camera of polarization array assembly respectively, birefringence effect is generated by stress at the tested piece, and photoelastic image with polarization information is collected by color polarized camera;Photoelastic image is generated by RGB channel synthesis algorithm to generate an achromatic photoelastic dark-field image;Based on photoelastic dark-field image, in combination with the calibration curve of RGB color value-equal difference line fringe number, equal difference line phase is solved;Based on the collected photoelastic image, equal inclination line phase is calculated using four-step phase shift method.Compared with the existing instantaneous photoelasticity method of circular polarized light path, the present application improves the precision and efficiency of color photoelasticity measurement and other advantages.

The utility model discloses a shear test device based on a photoelastic instrument, which comprises a photoelastic component, and a loading frame component is arranged in the middle of a light path of the photoelastic component; the loading frame assembly comprises a clamping frame assembly used for clamping a detected piece, the loading frame assembly comprises a transverse linear degree of freedom and a vertical linear degree of freedom, and the transverse linear degree of freedom is used for adjusting the stroke point position of the vertical linear degree of freedom. The transverse linear degree-of-freedom action is connected with a shearing assembly for a shearing test; the shearing assembly comprises at least three execution linear degrees of freedom which are coaxially and annularly arranged in an array mode, and the execution linear degrees of freedom are connected and act on the shearing unit to conduct universal angle adjustment; according to the utility model, through the combination arrangement of the multiple electric cylinders and the design of the universal joint couplings, the overall multi-direction and multi-dimensional angle adjustment of the shearing assembly is realized, so that the complex three-dimensional stress state can be better simulated and analyzed.