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163 results about "Polarization modulation" patented technology

Polarization modulation, in which the angle of rotation of an optical carrier signal is varied to reflect transmitted data.

Wafer detection method and detection system

The invention relates to the technical field of wafer detection, in particular to a wafer defect detection method and device, and aims to detect wafer defects by adopting a polarization modulation and decomposition scheme according to corresponding characteristics of wafer surface scattered light and defect scattered light in a wafer defect detection process. The wafer detection method for improving the wafer defect detection accuracy is formed, and the wafer detection system for improving the wafer defect detection accuracy is formed according to the wafer detection method.
Owner:ANGKUN VISION (BEIJING) TECH CO LTD +1

Ultrahigh time resolution camera time characteristic detection device and method

The invention relates to the technical field of optical precision measurement, in particular to an ultra-high time resolution camera time characteristic detection device and method, and the device comprises a laser source which is used for generating pulse laser; the polarization modulation element is arranged on an emergent light path of the laser source and is used for modulating the pulse laser into circularly polarized light; the spectroscope is arranged on an emergent light path of the polarization modulation element and is used for decomposing the circularly polarized light into a first linearly polarized light beam and a second linearly polarized light beam; the first optical path unit is used for guiding the first linearly polarized light beam to the cylindrical optical element along a fixed optical path; the second optical path unit is used for adjusting the optical path of the second linearly polarized light beam and guiding the second linearly polarized light beam to the cylindrical optical element; and the cylindrical optical element is used for receiving the first linearly polarized light beam and the second linearly polarized light beam and respectively projecting the first linearly polarized light beam and the second linearly polarized light beam to an imaging surface of a camera to be detected to form two spatially separated light spots. The objective of the invention is to improve camera time characteristic calibration precision and efficiency.
Owner:LASER FUSION RES CENT CHINA ACAD OF ENG PHYSICS

Calibration method of polarization focal plane imaging system and imaging system

The invention discloses a calibration method of a polarization focal plane imaging system and an imaging system, relates to the field of photoelectric imaging and remote sensing detection imaging, and solves the problems of low correction efficiency and difficulty in correcting a system with a changed polarization state in the conventional polarization error correction technology. According to the calibration method, a plurality of coding patterns and corresponding polarization modulation matrixes are obtained based on the collected uniform light field and serve as calibration results. The polarization error correction method comprises the steps of obtaining an observation intensity vector based on a target scene; a corresponding polarization modulation matrix is obtained based on the coding pattern according to a coding polarization modulation matrix lookup table, and then a down-sampling Stokes vector after polarization error correction is obtained; and completing the correction of the polarization error through an imaging reconstruction method. A polarization focal plane imaging system comprises an imaging lens, a DMD digital micromirror array coding module, a focal plane DoFP polarization detector and an imaging reconstruction module. The method is suitable for the fields of remote sensing detection, target identification, environment monitoring and the like.
Owner:CHANGCHUN UNIV OF SCI & TECH

Multi-channel spectrum-controllable liquid crystal display system and display method

The invention discloses a multi-channel spectrum-controllable liquid crystal display system and a multi-channel spectrum-controllable liquid crystal display method. The system comprises a multi-channel backlight module, a liquid crystal display panel and a control module, the multi-channel backlight module is used for generating a backlight source comprising a plurality of spectrum sub-channels, the spectrum sub-channels cover different spectrum ranges, and the output intensity can be independently adjusted; the liquid crystal display panel comprises a liquid crystal layer, a first polaroid, a second polaroid, a red color filter, a green color filter and a blue color filter, wherein the red color filter, the green color filter and the blue color filter are arranged on the liquid crystal layer and used for conducting spectrum selection and polarization modulation on light from the multi-channel backlight module. The control module is used for cooperatively controlling the backlight output intensity of each spectrum sub-channel and the driving parameters of the liquid crystal display panel according to the display target containing the target spectrum distribution constraint on the premise of not changing the color filter structure and the pixel arrangement structure of the liquid crystal display panel; therefore, controllable reconstruction of the display spectrum output by the liquid crystal display panel is realized. An existing liquid crystal display panel structure does not need to be changed, the regulation and control freedom degree of a display system on the output spectrum can be improved, and a system-level solution is provided for achieving the display effect close to natural spectrum distribution.
Owner:SUZHOU UNIV OF SCI & TECH

Photoacoustic spectrum signal detection system and detection method

The application discloses a photoacoustic spectrum signal detection system and a detection method. The system comprises a signal acquisition device and a detection signal processing terminal. The signal acquisition device comprises an ultraviolet pulse laser, a first plano-convex lens, a second plano-convex lens, a focusing objective lens, a refractive prism, a helium-neon laser, an electric displacement platform, a polarization modulation assembly, a light splitting assembly and a differential detector. The photoacoustic spectrum signal detection system uses the specific absorption of cell nuclei to ultraviolet light, obtains a differential detection signal through the differential detector and generates an analysis spectrum. The light sensing assembly collects a light sensing signal of the sample and generates a microscopic image. The detection system can realize photoacoustic spectrum analysis of a cell nucleus level micro-sized absorber, thereby obtaining a high-resolution analysis spectrum and a microscopic image reflecting the physical properties inside the cell nuclei. The label-free and non-staining photoacoustic spectrum signal detection does not need staining and can save detection time, and the accuracy of cell detection on biological samples is improved.
Owner:SHENZHEN UNIV

Method and apparatus for generating a random polarized light beam

This invention relates to beam manipulation, providing a method and apparatus for generating randomly polarized beams, and pertains to the field of optical manipulation technology. The method includes generating a highly coherent linearly polarized beam using a continuous excitation light source unit; modulating the linearly polarized beam using a phase modulation unit to obtain a vortex beam with arbitrary topological charge; and modulating the vortex beam into a randomly polarized beam using a polarization modulation unit, wherein the response range of the random polarization can cover any point on the surface of a Poincaré sphere. The beam generation method provided by this invention can modulate a vortex beam carrying arbitrary topological charge into a beam with randomly varying polarization states, exhibiting high modulation efficiency, uniform polarization state distribution, and low cost, thus possessing significant practical value.
Owner:SHENZHEN UNIV

Quantitative detection method for anti-perspective performance of textile in complex light environment

The invention discloses a quantitative detection method for anti-perspective performance of a textile in a complex light environment, and belongs to the technical field of new material detection, a micro gap is arranged between the textile to be detected and a variable-frequency gray scale target to simulate a non-clinging state when clothes are worn and excite Fresnel diffraction and subsurface scattering effects, and the anti-perspective performance of the textile is detected. Complex illumination conditions such as backlight and sidelight are simulated by adjusting the light intensity ratio, and after a target perspective image is acquired by using an image acquisition unit, the modulation transfer function attenuation rate of a to-be-detected textile to the target is calculated, so that the anti-perspective performance of the textile is quantitatively represented; the interference of glare on the surface of the high-gloss fabric is effectively eliminated by introducing an orthogonal polarization modulation technology, and a detection result is highly consistent with the visual perception of human eyes by adopting a specific light source spectrum simulating the skin color of a human body; compared with a traditional light transmittance method, the method has the advantages that the dimension crossing from luminous flux measurement to image information fidelity evaluation is realized, and the accuracy, reliability and practicability of detection are remarkably improved.
Owner:SUZHOU ZHONGKE TEXTILE TECH SERVICE

An exposure apparatus based on a spatial phase modulator and a liquid crystal device

The application relates to an exposure device based on a spatial phase modulator and a liquid crystal device, which comprises a light source control module, a light intensity and polarization control module, a focusing servo module, a sample setting module, a voltage control module and a monitoring module, the light source control module comprises a first switchable mirror and a light source switching assembly, the light intensity and polarization control module comprises a light intensity modulation assembly for receiving a light beam output by the light source control module and modulating the light intensity of each pixel point in the light beam, and a polarization modulation assembly for modulating the polarization state of each pixel point in the light beam emitted by the light intensity modulation assembly; the first switchable mirror is used for switching the light path between the light intensity modulation assembly and the polarization modulation assembly; the focusing servo module and the sample setting module are both switched to face the polarization modulation assembly or the first switchable mirror. Compared with the prior art, the exposure device has more degrees of freedom, the exposure process is simple and efficient, and the needs of experimental teaching and scientific research engineering can be met.
Owner:EAST CHINA UNIV OF SCI & TECH

An intelligent sensing system for ground construction risk monitoring

The present application belongs to the field of geophysical exploration and geoscience information sensing technology, and relates to an intelligent sensing system for ground construction risk monitoring, comprising: a pulse generation module for generating a detection pulse sequence with a preset time interval; an orthogonal polarization modulation module for mapping the detection pulse sequence with an orthogonal polarization state and loading a time delay modulation; a distributed sensing module for receiving pulse combination and generating a backscattering signal; a common mode interference cancellation module for superimposing the backscattering signal in the photon domain to generate a phase push effect, in-situ canceling a static resident stress background noise, and extracting a dynamic birefringence phase shift amount; and a signal decoupling analysis module for identifying a dynamic shear signal according to a covariance tensor principal eigenvalue extraction value. The present application utilizes an optical domain physical interference cancellation mechanism to annihilate static background interference, realizes high-fidelity physical extraction of weak dynamic signals, and improves the identification ability of the system for structural medium shear instability.
Owner:POWERCHINA JIANGXI ELECTRIC POWER ENGINEERING CO LTD

A polarized light microscopy system and method for inspecting semiconductor light emitting chips

ActiveCN116046776BInvestigating semiconductor impuritiesUsing optical meansImaging processingLight spot
The application discloses a kind of detection semiconductor light-emitting chip's polarized microscopy system and method, system includes chip excitation module, incident illumination modulation module, microscopic adjustment module, exit imaging module and control and image processing module.The application is continuously polarized by control module to incident illumination modulation module Modulation, modulated incident light is acted on light-emitting chip exit end face by microscopic system module, simultaneously using control module to adjust exit imaging module and carry out real-time image collection, obtain the polarized parameter image of exit end face by image processing module;Close incident illumination module, after using chip excitation module to excite light-emitting chip, adjust three-dimensional platform and exit imaging module by control module, real-time image collection, finally obtain the polarized parameter diagram of near-field light spot by image processing module.The application has very strong characterization ability and high sensitivity to the end face structure and near-field light spot of semiconductor light-emitting chip.
Owner:NANJING UNIV OF SCI & TECH

A multi-target detection method based on entangled light quantum

This invention proposes a multi-target detection method based on entangled photons. First, a pump light is generated using a continuous narrow-linewidth semiconductor laser, which, after polarization modulation and focusing, illuminates a PPKTP crystal. A spontaneous parametric down-conversion process generates polarization-entangled photon pairs, which are then separated into signal and reference light. These are received by a single-photon detector to obtain two time series. Second, coincidence measurements are performed on the time series in different scanning directions within the observation area to obtain a coincidence count matrix. Then, a two-dimensional constant false alarm rate (CFAR) detection algorithm is introduced, using ordered statistics to estimate background noise and adaptively adjust the detection threshold to screen candidate target points. Third, a density clustering algorithm based on correlation strength weighting is employed, combining the correlation strength and spatial distribution of entangled photon pairs to detect different targets and suppress isolated noise. Finally, the coincidence count peak points within each target cluster are selected as the final detection targets, thereby achieving multi-target detection with unknown numbers and randomly distributed locations.
Owner:CHONGQING UNIV OF POSTS & TELECOMM

Optical system and optical processing apparatus

The embodiment of the invention provides an optical system and optical processing equipment. The optical system comprises a light source module, a polarization modulation module, a micromirror array and an objective lens assembly. The light source module is used for outputting femtosecond laser pulses. The polarization modulation module is used for receiving the femtosecond laser pulse and modulating the polarization state of the femtosecond laser pulse into a circular polarization state. And the micro-mirror array is used for receiving the femtosecond laser pulse in the circular polarization state and performing spatial modulation on the femtosecond laser pulse to generate different patterns. The objective lens assembly is used for receiving and focusing the pattern to the surface of the sample. Thus, the femtosecond laser pulse passing through the polarization modulation module has the same polarization state in all directions, so that the absorptivity and the working efficiency of different positions of the sample M are consistent in the laser processing process, and the processing quality and effect are improved. Moreover, the micro-mirror array is sensitive to the polarization state, so that energy loss and non-uniformity caused by polarization can be avoided, and the processing uniformity and the processing precision can be further improved.
Owner:WUXI PHOTONIC CHIP JOINT RES CENT

A full polarization spectral imaging device and detection method

The application discloses a kind of full polarization spectral imaging device and detection method, contain sequentially arranged polarization modulator, imaging spectrometer, data acquisition processing display system to incident light;Polarization modulator is single fixed retarder and single fixed linear polarizer sequentially arranged along incident light, can carry out spectral modulation to full stokes parameter, it has the superiority of simple, ultra-compact, miniaturization, anti-system error in structure.By constructing complete imaging physical model or constructing imaging physical model based on compressed sensing, then using untrained artificial neural network realizes the full stokes parameter image reconstruction under each narrow waveband, and the deep neural network of "black box operation" is endowed with physical meaning.The reconstructed polarization spectral resolution can be consistent with the resolution of the imaging spectrometer used;And it has the characteristics of strong anti-noise ability, so as to ensure high-quality reconstruction.
Owner:CAIPU TECHNOLOGY (ZHEJIANG) CO LTD

A photochromic circularly polarized luminescent carbon dot long afterglow composite material and a preparation method thereof

The application discloses a kind of photochromic circular polarized luminescent carbon dots long afterglow composite materials and preparation method and application thereof, belong to chiral luminescent functional material technical field;The composite material with photochromic and long afterglow luminescence characteristics carbon dots as luminescent center, and with cellulose nanocrystal through self-assembly to form chiral composite system with cholesteric helical structure.Carbon dots provide fluorescent emission, photochromic and long afterglow luminescence characteristics, while the chiral structure of cellulose nanocrystal can selectively circularly polarized modulation to luminescence, so as to realize the enhancement of circular polarized luminescent signal.The composite material can realize reversible photochromic luminescence behavior under ultraviolet irradiation, and produce long afterglow emission after excitation stops, while showing obvious circular polarized luminescence characteristics.The material has the advantages of stable structure, simple preparation method, high functional integration, etc., and has good application prospect in information anti-counterfeiting, optical encryption, chiral optoelectronic devices and intelligent display fields.
Owner:NANJING UNIV OF POSTS & TELECOMM

Light field three-dimensional reconstruction method and system based on microlens array and polarization modulation, and medium

The application provides a light field three-dimensional reconstruction method, system and medium based on a microlens array and polarization modulation, the method comprising: polarization encoding different angle light rays at an exposure moment based on a polarization modulator to obtain different polarized light information; focusing the light rays to an imaging surface based on an imaging lens, recording a view angle graph of different polarized light information based on a microlens array; based on the polarization characteristics of the view angle graph, decoding the view angle graph based on the polarization characteristics to obtain light field images of multiple view angles; preprocessing the light field images of multiple view angles to obtain preprocessed images of multiple view angles; analyzing light intensity distribution information based on the preprocessed images to obtain light field data, reconstructing the light field images based on a reflection projection algorithm to obtain reconstructed images; realizing multi-view image capture through multi-state polarization encoding, and analyzing the light intensity of the multi-view light field images to realize three-dimensional reconstruction of a high-speed dynamic scene and improve image reconstruction accuracy.
Owner:HANGZHOU HUICUI INTELLIGENT TECH CO LTD

Method and system for detecting subsurface defects of optical elements based on phase-contrast digital holography

The application discloses an optical element subsurface defect detection method and system based on phase contrast digital holography, and belongs to the field of precision measurement technology; the system adopts annular Bessel beam Kohler illumination, utilizes polarization modulation technology and a specially-made polarization contrast ring to realize synchronous four-step phase shift high-speed quantitative phase measurement in a U-shaped light path; the method acquires complex amplitude through a polarization camera, compensates for resolution loss by using a self-supervision super-resolution reconstruction algorithm fused with a physical model; full-field and local inverse diffraction reconstruction is carried out based on angular spectrum diffraction theory, high-precision depth positioning is realized based on the diffraction light complex amplitude distribution characteristics as a focusing criterion; three-dimensional information representation of defects is realized in combination with an optical field scattering and diffraction model and a machine learning algorithm; the application can realize high-sensitivity, high-signal-to-noise ratio, real-time in-situ quantitative detection and three-dimensional reconstruction of submicron defects without significantly increasing the cost.
Owner:FUDAN UNIVERSITY

A polarization state modulation method based on regular polyhedral constellation points

This invention discloses a polarization state modulation method based on regular polyhedral constellation points, comprising: selecting the order of polarization modulation and the corresponding regular polyhedral class; dividing the original binary bitstream into a conventional modulation bitstream and a polarization state modulation bitstream, wherein the conventional modulation bitstream is used to generate conventional modulation symbols, and the polarization state modulation bitstream is used for polarization state mapping; obtaining the corresponding polarization state description parameters using the polarization state modulation bitstream and the order of polarization modulation, determining the polarization weighting factor and performing polarization weighted fusion to obtain dual-channel high-dimensional modulation symbols to be transmitted; transmitting the symbols through an orthogonal dual-polarization antenna after preprocessing; performing RF front-end processing on the received horizontal and vertical polarization components of the RF signal at the receiving end to obtain the Jones vector representation of the baseband received signal; recovering the polarization state information by combining the Stokes parameters, and recovering the original binary bitstream by combining the conventional modulation and demodulation results.
Owner:NORTHWESTERN POLYTECHNICAL UNIV

A wide-spectrum, high-bandwidth static spectral modulation Stokes polarization measurement device

This application relates to the field of optical polarization measurement technology, specifically to a wide-spectrum, high-bandwidth static spectral modulation Stokes polarization measurement device, comprising a polarization modulation module, a spectral sampling module, and a high extinction ratio polarizer. The polarization modulation module includes a phase retarder and a linear polarizer; the spectral sampling module has sub-nanometer spectral resolution; the high extinction ratio polarizer includes a halogen tungsten lamp and a Glan Taylor prism for generating high-purity linearly polarized light; the obtained demodulation factor and the modulation spectrum acquired by the spectral sampling module are used to invert the Stokes parameters using zero-heterodyne coherent demodulation technology. This application employs a phase retarder with high birefringence, which, for the same thickness, produces an optical path difference tens of times greater than that of quartz, increasing the Stokes polarization measurement bandwidth by a factor of the response and improving the measurement accuracy of polarization spectral parameters. Simultaneously, the zero-heterodyne coherent demodulation method is used to eliminate the dispersion interference of the phase retarder through calibration.
Owner:LANZHOU INST OF PHYSICS CHINESE ACADEMY OF SPACE TECH

Optical signal inner-circulation delay system based on electro-optic polarization control

ActiveCN117856909BRing-type electromagnetic networksMultimode transmissionContinuous lightControl signal
The application discloses an optical signal inner circulation delay system based on electro-optic polarization modulation, comprising a signal light source, a first polarization beam splitter prism, a first electro-optic polarization modulator, a second polarization beam splitter prism, a second electro-optic polarization modulator, a third polarization beam splitter prism, a first full reflection mirror, a first lens, a first optical fiber collimator, a single-mode / multi-mode optical fiber, a second lens, a second optical fiber collimator and a second full reflection mirror, forming a ring-shaped light path. The length of the single-mode / multi-mode optical fiber and the high level duration of the modulation electric signal are adjusted, the repetition frequency and the pulse width of the output optical signal can be changed respectively, and therefore the application can also be used for converting continuous light into controllable pulsed light. The number of times that the signal light circulates in the ring-shaped light path can be controlled through the loaded electric signal, the delay time is flexibly adjusted, and the delay time range is expanded.
Owner:SOUTH WEST INST OF TECHN PHYSICS

Confocal full mueller matrix imaging apparatus and method based on fiber superstate array

The application discloses a confocal full Mueller matrix imaging device and method based on a fiber super surface array, and belongs to the technical field of polarized optical imaging. The device comprises a fiber array multi-polarization illumination module, a sample scanning module, a scattered light transmission module, a super surface array polarization modulation module and a polarized light intensity detection module. The polarization state of four beams of light is regulated by a fiber polarization controller, and four illumination focal spots with different polarization states are generated simultaneously on a sample plane. The sample scattered light is modulated by a polarization measurement super surface array comprising four independent super surface units, and the polarization state of each light signal is projected onto sixteen spatially separated polarized light spots. Finally, the light spot intensity information is collected by a surface array detector, and the full Mueller matrix image of the sample is reconstructed by calculation. The application realizes the acquisition of full Mueller matrix information in a single scan, has the characteristics of high resolution, compact structure and good compatibility, and can be used for multi-dimensional polarization microscopic analysis of samples.
Owner:UNIV OF SCI & TECH OF CHINA

Display system with fusion design of eye movement camera shooting and near-to-eye display light path

The invention relates to the technical field of augmented reality display, in particular to a display system with eye movement camera shooting and near-to-eye display light path fusion design, which comprises a display optical assembly, an image source, an eye imaging assembly and an infrared lamp, the display optical assembly comprises at least one lens; each lens is attached to an optical film material to perform polarization modulation on a light beam in a light polarization state, so that a near-to-eye display light beam and an eye imaging light beam are independently transmitted in the display optical assembly in different polarization states; the image source is used for generating a near-to-eye display light beam with a circular polarization state; the eye imaging assembly comprises at least one eye camera used for imaging an eye area, and the eye camera is arranged between the display optical assembly and the image source and located outside the near-to-eye display light path; and the infrared lamp is arranged at the side end of the display optical assembly, is close to one side of human eyes, and is used for providing eye imaging light beams required by eye imaging. The system can ensure clear imaging of the eye area by the eye camera while a near-to-eye display light path is not influenced.
Owner:LUOYANG INST OF ELECTRO OPTICAL EQUIP OF AVIC

An epitaxial structure and method of epitaxy of a high linearity AlGaN / GaN heterojunction

The application discloses an epitaxial structure and method of a high-linearity AlGaN / GaN heterojunction, which sequentially comprises a single-crystal substrate, an AlN nucleation layer, a GaN buffer layer, a GaN channel layer, an AlGaN channel layer, a first AlGaN barrier layer and a second AlGaN barrier layer. The technical scheme uses epitaxial technologies such as metal organic chemical vapor deposition (MOCVD), adopts a high-temperature and low-rate process for the GaN channel layer, improves the crystallization quality and surface morphology of the GaN channel layer, and is favorable for reducing the defect density of the subsequent AlGaN channel layer and barrier layer. The AlGaN channel layer structure is introduced, the small conduction band step of the AlGaN channel layer / GaN channel layer is used, three-dimensional distribution of an electron gas in the GaN / AlGaN composite channel layer is realized, the first AlGaN barrier layer structure of polarization modulation doping is introduced, the electron gas penetrates into the barrier layer, and the three-dimensional depth of the electron gas is further widened, the second AlGaN barrier layer with strong polarization is used, the electron gas surface density and the transconductance peak value are improved, and the application is suitable for the development of a high-linearity GaN radio frequency device.
Owner:NO 55 INST CHINA ELECTRONIC SCI & TECHNOLOGYGROUP CO LTD

A broughst window stack polarization modulation device

The application discloses a Brewster window stack polarization modulation device. The device comprises a Brewster window stack assembly, a clamping assembly, and an installation base. The Brewster window stack assembly comprises a plurality of optical window pieces arranged in parallel and at intervals, and the included angle between the surface normal and the incident light is a Brewster angle. The installation base has a vertical part and a horizontal part. The clamping baffle is arranged opposite to the vertical part of the installation base at intervals. The optical window pieces and the gaskets are alternately arranged in parallel at intervals. One adjusting screw is arranged on each side of the installation base. The adjusting screw passes through the clamping baffle and each gasket in sequence, and is screwed with the vertical part of the installation base. The rotation of the adjusting screw is converted into the linear motion of the clamping baffle along the support surface, so as to change the distance between the clamping baffle and the vertical part and / or realize the clamping and fixing of the Brewster window stack assembly. The device can realize linearly polarized light output with high extinction ratio and high stability in a wide range of incident angles and spectral bands.
Owner:ZHEJIANG UNIV

Polarization perception adaptive defogging method and device based on autonomous prompt

The invention discloses a polarization sensing self-adaptive defogging method and device based on autonomous prompt, and the method comprises the steps: obtaining a descriptor based on the Fourier polarization modulation according to a polarization input feature image, projecting the descriptor to a potential space with a set scale, obtaining a descriptor under the scale s, and carrying out the defogging of the descriptor under the scale s; and finally, inputting the intensity input image into a prompt enhancement U-Net module based on a cross attention mechanism so as to obtain a defogged image according to the re-parameterized prompt word and the intensity input image. Therefore, the invention constructs a set of high-robustness image processing method oriented to the extreme atmospheric environment, and the generalization ability and robustness in a complex environment are improved.
Owner:XIDIAN UNIV

Femtosecond laser pulse compression system with compact structure and adjustable pulse width

The invention provides a femtosecond laser pulse compression system with a compact structure and an adjustable pulse width, and relates to the technical field of femtosecond lasers, the system sequentially comprises a seed source, a pulse stretcher, an amplification chain and a pulse compression device along a light path, the pulse compression device comprises a polarization beam splitting unit, an electro-optical polarization modulation unit, a single compression grating and a light path turn-back unit; wherein the polarization beam splitting unit, the electro-optical polarization modulation unit, the single compression grating and the light path turn-back unit jointly form a multi-channel folding compression light path; a voltage signal with a specific time sequence is applied to the electro-optical polarization modulation unit, and the polarization state of a light beam is dynamically switched, so that the light beam is selectively controlled to complete back-and-forth transmission of a preset number of times in a multi-channel folding compression light path in different polarization states, and the compression ratio of laser pulses and the width of output pulses are continuously adjusted. On the premise that large-spread-width matching is guaranteed, the system is extremely compact, and the pulse width is continuously and flexibly adjusted in an electric control mode.
Owner:TIANJIN UNIV

Multi-mode low-light imaging test system based on laser induction

The invention provides a multi-mode low-light imaging test system based on laser induction. The multi-mode low-light imaging test system comprises a multi-mode light source module, a polarization modulation and light path coupling module, a low-light adjusting module, an imaging module, a detection module and a temperature control module which are sequentially connected according to an optical path, the multi-mode light source module comprises a laser, a laser collimator and a halogen lamp; the polarization modulation and light path coupling module comprises a first beam expander, a second beam expander, a PBS, a first polaroid, a second polaroid, a reflector, a first dichroscope and a beam splitter. The low-light adjusting module is a diaphragm; the imaging module comprises an objective lens and a barrel lens; the detection module comprises a second dichroscope, an InGaSe detector and a visible light detector. The beneficial effects of the invention are that through multi-light-source cooperation and dual-detection modes, infrared and visible light full coverage, application scene expansion, polarization modulation, stray light suppression by the adjustable diaphragm, detector noise reduction by the temperature control module are realized, low-light imaging signal-to-noise ratio and resolution are significantly improved, and the system is compact in structure, easy to integrate and high in detection stability.
Owner:SUZHOU ZHISHENG OPTOELECTRONICS TECH CO LTD

Optoisolator coupling control method and system for keeping light polarization state stable

The invention relates to the technical field of optics, and provides an optical isolator coupling control method and system for keeping the light polarization state stable. The method comprises the steps that light polarization states are classified according to light polarization inducements, and polarization categories are divided; according to the polarization type, a modulation decision module is built, and the output end of the modulation decision module is in communication connection with an electro-optical modulator; and the control module is used for identifying a light scene, triggering the detection equipment group, detecting the operation process of the optoisolator, judging whether to activate the modulation decision module or not according to a triggering condition, determining a polarization modulation strategy, and responding to the electro-optical modulator to carry out light modulation driving control. The technical problem that the isolation performance of the optical isolator is reduced due to the fact that the light polarization state is prone to instability in a dynamic environment is solved, and the technical effect of achieving high-precision, real-time and stable optical isolation control through self-adaptive polarization modulation is achieved.
Owner:WUHAN YILUT TECH CO LTD

A coherent transmission method based on digital subcarrier multiplexing and a PON system

This invention discloses a coherent transmission method and PON system based on digital subcarrier multiplexing, relating to the field of optical access network technology. The method includes: in the downlink transmission direction, the OLT transmitter generates an Alamouti-coded signal of M digital subcarriers, performs digital-to-analog conversion and dual polarization modulation, and transmits it as a downlink signal to the ONU receiver; the ONU receiver performs heterodyne coherent detection, analog-to-digital conversion, and digital signal processing, with the downlink signal occupying a single-sideband spectrum of the ONU's light source; in the uplink transmission direction, the ONU transmitter generates data of M digital subcarriers, performs digital-to-analog conversion, and then performs single-sideband modulation based on the ONU's light source, transmitting it as an uplink signal to the OLT receiver, with the uplink signal occupying another single-sideband spectrum; the OLT receiver performs analog-to-digital conversion and digital signal processing after coherent reception. This application enables bidirectional high-speed transmission, and uses the same light source for both transmission and reception at the ONU, which increases the capacity of the PON system, simplifies the ONU's structure and algorithm, and reduces system costs.
Owner:WUHAN POST & TELECOMM RES INST CO LTD

Chip detection device and chip detection method

PendingCN122281995AVisual recognitionImage flow
This invention discloses a chip testing device and a chip testing method. The device includes a probe module, a polarization-modulated multispectral optical path system, an excitation sampling unit, and a heterogeneous data fusion processing system. The probe module includes an opaque carrier, a transparent element embedded in a hole in the carrier, and a cantilever probe array arranged at the bottom of the carrier. The polarization-modulated multispectral optical path system is arranged above the transparent element. The excitation sampling unit is used to apply power pulse excitation to the chip under test, and can simultaneously acquire the electrical response sequence generated by the probe module and the optical feature image stream acquired by the polarization-modulated multispectral optical path system. The heterogeneous data fusion processing system includes a visual recognition module and a physical inversion module. The visual recognition module is used to identify stress distortion regions from the optical feature images. The physical inversion module substitutes the stress distortion regions into the PINN model, combines the electrical response sequence, and inversely deduces the deep physical state variables inside the chip under test.
Owner:SHENZHEN GUODE IND CO LTD