18 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.

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.

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 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 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.

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.

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 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 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 application relates to the field of image processing, and discloses an intelligent detection method for surface defects of a wind turbine blade based on image processing, which is used for improving the accuracy of surface defect detection of the wind turbine blade. The method comprises the following steps: fusing pulse laser thermal excitation infrared thermal imaging and a multi-angle polarized light source array polarization imaging technology, constructing a dual-mode data set, extracting thermal anomaly features from a dynamic thermal image sequence, and obtaining photoelastic stress features through phase analysis and local energy filtering. The features are fused by using a thermal conduction blocking and stress concentration space coincidence reinforcement mechanism, a fusion defect indication map is generated, a defect probability distribution map is obtained, a risk value is calculated and predicted, a repair strategy library is matched according to the risk value, a repair scheme code is output, and a three-dimensional repair guide map is generated. The application realizes intelligent and accurate detection and repair guidance of the surface defects of the blade, and improves the comprehensiveness and accuracy of defect detection.

The application discloses a kind of optical nondestructive testing system and method of substrate residual stress, system includes light source, modulation module, beam splitter, sample stage, demodulation module, image acquisition module;Light source, modulation module and beam splitter are sequentially arranged along straight line A, beam splitter, demodulation module and image acquisition module are sequentially arranged along straight line B, straight line A is perpendicular to straight line B, the line connecting sample stage and beam splitter is perpendicular to straight line A and straight line B simultaneously.When measuring, the laser emitted by light source reaches image acquisition module after passing through modulation module, beam splitter, material to be measured and demodulation module, is collected to form a series of interference images, and the direction and size of substrate residual stress are calculated by the relationship between light intensity signal, optical component parameter and equal inclination angle and phase difference.The application detects system by perpendicular incidence type reflected photoelastic optical path, improves the system error caused by small-angle incidence of existing reflected photoelastic system, and realizes high-precision detection of substrate residual stress.

The application discloses a kind of temperature measurement method and device based on photoelastic modulation magneto-optical Kerr optical system, belong to magneto-optical detection and temperature measurement technical field, comprising: S 1, the optical axis azimuth angle of the polarizer and the photoelastic modulator is adjusted, so that the detection light intensity of the photoelectric detector only has direct current component;And the optical axis azimuth angle α of the polarizer is set to be less than 45°, and under the azimuth angle α, the detection light intensity is greater than the quantization error of data acquisition;S2, according to the detection light intensity, the direct current amplitude, the first harmonic amplitude and the second harmonic amplitude of light intensity at photoelastic modulation frequency are obtained by Fourier transform;S3, the magneto-optical signal of magnetic nanometer film sample is calculated;S4, the temperature of the magnetic nanometer film sample is changed, and the numerical relationship between the magneto-optical signal MO (T) and temperature T is calibrated.The application can directly measure temperature based on photoelastic modulation magneto-optical Kerr optical system, and the resolution of temperature measurement on the surface of sample can reach mK level.

The application discloses a kind of left and right circular polarization state fast response's optical orbital angular momentum high-speed detector and method.The present application is based on high-speed polarization modulation technology and orbital angular momentum detector, realize the information of high-speed detection light orbital angular momentum;Compared with the detection speed of minute order based on traditional detection method, the present application will light orbital angular momentum The detection speed of momentum is promoted to millisecond order, while the number of quantum of light orbital angular momentum can be directly distinguished by the circular polarization dependent component of radial photocurrent extracted by phase-locked amplifier, without additional calculation and data processing by computer;Since photoelastic modulator has a large wavelength range, the present application can also be applied to light orbital angular momentum detection in a larger wavelength range;The present application is applied to various light orbital angular momentum detection application occasions, such as infrared imaging, military investigation and focal plane imaging.

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.