1241 results about "Optical pathlength" patented technology

The invention relates to an error compensation method of a birefringence self-calibration laser level meter, in particular to the field of laser level meters, and aims to improve the precision of the laser level meter by combining a birefringence effect, physical modeling and neural network optimization. Firstly, temperature data are collected in real time, Kalman filtering is used for noise reduction, and accurate data are provided for physical modeling; then, through physical constraints such as a heat conduction equation and a Jones matrix, a coupling relation between the temperature gradient and optical parameter changes is established; then, dynamically optimizing the refractive index correction by using a physical information neural network to avoid an overfitting problem; and finally, calculating optical path difference compensation by using a hardware accelerator, correcting a system error in real time, and feeding back and adjusting a network weight. According to the method, the precision and the stability of the laser level meter in an environment with relatively large temperature change are effectively improved.

The invention provides an optical measurement method and device, and belongs to the technical field of optical measurement, and the method comprises the steps: starting a light source with the wavelength changing dynamically to generate a sweep frequency optical signal; dividing the light into a measuring beam and a reference beam by using a light splitting component, guiding the measuring beam to irradiate a target to be measured and then return along the same path, and guiding the reference beam to enter an optical component of which the optical path changes along with the wavelength and then return; based on the low-coherence characteristic of the light source, when the optical paths of the two light beams meet the interference condition, detecting an interference signal by using a sensing component; the optical path difference is determined according to time information in the interference signal, and the thickness of each reflection interface is calculated by combining refractive index data of a target to be measured. Different from the traditional low-coherence interference measurement which depends on a motor and the like to control the movement of a reflector, the method avoids the limitation of mechanical driving on the measurement frequency, and achieves the high-speed optical thickness measurement.

The invention relates to the technical field of length measurement, and particularly discloses a length measurement device based on laser interference, which comprises a laser measurement module, an air curtain channel module, an air curtain construction module and a channel adjustment module, the laser measuring module is used for transmitting and receiving laser, the optical path difference change is measured according to the interference principle, and the micro length change of the workpiece can be continuously and accurately measured in real time while the machining module carries out machining operation on the workpiece; a linear channel is formed between the laser head and the measuring reflector through the air curtain channel module, inert gas is continuously introduced into the channel through the air curtain construction module, and an air curtain atmosphere with stable laminar flow is formed, so that pollutants and interference factors such as oil mist, dust, cutting fluid splashing and hot air turbulence generated in a machining area are effectively blocked, and the machining precision is improved. Therefore, the measurement light beam is prevented from being interfered by environmental factors in the propagation process.

The invention discloses a method and a device for correcting laser focusing aberration in a transparent material, and belongs to the technical field of laser processing. The method comprises the steps that a machining light path containing an object plane, an aspheric reflector and a 4F device is built in Zemax, the surface type of the aspheric reflector is optimized with the minimum focus aberration as the target, and a rise table is derived; an optical path difference and a laser phase are calculated through Matlab, and a phase diagram is generated; and an actual machining light path is built, and a phase diagram is loaded to achieve low-aberration machining. Simulation optimization and phase modulation are combined, aberration caused by refractive index difference is effectively counteracted, wavefront errors are reduced by 58%, the thickness of a machining damage layer is reduced by 70%, the method is suitable for various transparent materials, the machining precision and the material utilization rate are improved, and the method is suitable for high-precision laser machining scenes.

The invention provides a rapid evaluation method and system for the soil fertility level, and relates to the technical field of soil fertility detection.The rapid evaluation method comprises the steps that an original absorbance spectral data curve is obtained by scanning a soil sample, the moisture peak absorbance, the actual peak position wavelength and the moisture synthetic frequency characteristic peak width are extracted, and a spectral data basis is provided; a water-salt optical path coupling factor is calculated, water-salt correction operation is carried out in combination with a volume correction coefficient, a virtual dry soil spectrum data curve is obtained, interference of salt on a water optical path is quantified, and a water background and salt masking are eliminated; constructing a characteristic virtual baseline of the organic matter and the total nitrogen, calculating an integral area to obtain characteristic intensity of the organic matter and the total nitrogen, and providing a physical input variable for quantitative inversion; introducing a water-salt optical path coupling factor to invert the organic matter content and the total nitrogen content, and correcting signal depression caused by salt stress; the effective fertility index is calculated and graded by combining the organic matter content and the total nitrogen content of the soil, and the actual fertilizer supply capacity of the soil is comprehensively evaluated.

The invention relates to the technical field of image processing, in particular to an optical thin film quality detection method based on image processing, which comprises the following steps: S101, acquiring a transient light field image sequence of an optical thin film in a dynamic stress field; s102, performing spectral analysis on the brightness time sequence of each pixel point, extracting a dominant frequency component as a brightness oscillation period, processing time domain fluctuation data by adopting a Fourier transform algorithm, and calculating a local optical path difference variation based on the brightness oscillation period of each pixel point in the image sequence; and S103, projecting the phase distortion field to a preset film elastic modulus distribution model, establishing a phase distortion-stress distribution-defect mapping relation, and identifying a modulus mutation region. A dynamic stress field is generated through the synergistic effect of mechanical vibration and thermal radiation, remarkable stress concentration can be generated at the micro-defect position, the deformation difference of the micro-defect is amplified, and therefore the sensitivity of defect detection is improved.

The invention discloses a dynamic leaching-spectrophotometric detection method for the release rate of nutrients in a slow-release fertilizer, and relates to the field of agrochemical analys.The detection method comprises the following steps that S1, a slow-release fertilizer sample is placed in a leaching column to be leached, and leachate is collected; s2, sequentially adding a masking agent solution and a chromogenic reagent into the leachate, and carrying out chromogenic reaction; s3, pumping the solution into a double-optical-path flow cell, and measuring absorbance values under a target nutrient characteristic absorption wavelength and a background interference characteristic wavelength; s4, calculating the corrected net absorbance; and S5, calculating the nutrient concentration, and drawing a nutrient release kinetic curve. By adopting a dual-wavelength synchronous detection and real-time dynamic subtraction correction algorithm, the method can eliminate system errors of time-varying background chromaticity, so that accurate and reliable absorbance readings can be obtained at the initial stage of nutrient release even if the nutrient concentration in the leachate is very low, thereby ensuring the authenticity of the initial stage of a release curve and improving the accuracy of nutrient release. And initial release kinetic parameters are accurately captured.

The invention relates to the technical field of medical image information processing, discloses an ICG fluorescence image and MRCP three-dimensional model registration fusion display method and system, effectively solves the problems of deep biliary tract structure blurring and form distortion caused by liver tissue scattering effect in intraoperative fluorescence imaging, uses a preoperative model as anatomical prior, and improves the accuracy of the intraoperative fluorescence imaging. A viewpoint correlation optical path depth field is constructed through reverse ray tracing, a spatial variation point spread function is generated accordingly, physical reverse recovery of scattering halo in a fluorescence image is achieved, non-specific background noise such as vascular leakage is effectively inhibited in combination with topological gravitational constraint of a central skeleton, and the detection accuracy is improved. The real pipe diameter and the center line position of the deep bile duct are accurately recovered, non-rigid registration correction is performed on the three-dimensional model based on the recovered high-fidelity image, and projection errors caused by respiratory movement and soft tissue deformation are eliminated.

The invention relates to a self-coherence optical fiber interference device and method for simultaneously measuring morphology and thickness. The device comprises a light source module (1), a measurement light path (2), a compensation light path (3), a spectrograph (4), a mechanical motion module (6) and a data processing module (5), the measuring light path (2) comprises an optical fiber circulator (21), an optical fiber retroreflector (22) and an optical probe (23) and is used for realizing focusing measurement and enabling reflected light of the end face of the optical fiber retroreflector (22) and reflected light of a transparent object to be measured to return; reflected light of the end face of the optical fiber retroreflector (2) and reflected light of the transparent object to be measured form a measuring light beam, and the measuring light beam enters the compensation light path (3); the compensation light path (3) comprises an optical fiber splitter (31), an optical fiber delay line (32) and an optical fiber coupler (33), the measuring light beam is subjected to optical path compensation to generate a compensation light beam, and the compensation light beam and the measuring light beam are combined and input into the spectrograph (4) together.

The invention relates to the technical field of water environment remote sensing monitoring, solves the technical problem of systematic overestimation or underestimation under the condition of algae bloom outbreak or strong stratification due to the fact that a water body is regarded as an optical uniform monolayer parameter in a traditional method, and particularly relates to a stratified light field correction chlorophyll-a remote sensing inversion method and system for an eutrophic lake. Performing vertical type identification and three-layer layering by using multispectral / hyperspectral remote sensing reflectivity, a synchronous chlorophyll-a vertical profile and a diffusion attenuation coefficient, calculating light field weight and light path weighted concentration of each layer, constructing a layered light field correction coefficient, performing layered light field correction on the remote sensing reflectivity, and establishing an empirical chlorophyll-a inversion relationship; and generating a chlorophyll-a spatial distribution map and an algae bloom risk map. According to the method, the layered light field correction coefficient with clear physical significance is constructed to correct the water surface remote sensing reflectivity, so that the inversion precision and robustness under strong layering and complex optical conditions are improved.

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.

The invention discloses a wide-spectrum interference weak signal enhancement method for high aspect ratio micro-nano structure measurement, and relates to the technical field of semiconductor measurement. The method comprises the following steps: acquiring a wide-spectrum interferogram, and performing two-layer two-dimensional discrete wavelet transform to obtain a first-stage wavelet coefficient group; performing nonlinear enhancement on the wavelet coefficient, and outputting a nonlinear enhanced wide-spectrum interferogram; performing three-layer two-dimensional discrete wavelet transform on the wide-spectrum interferogram after nonlinear enhancement to obtain a second-stage wavelet coefficient group, and calculating a Bayesian threshold value; a neighborhood sliding window function is set, and a Bayesian threshold is combined to carry out local denoising enhancement on the second-stage wavelet coefficient; reconstructing the second-stage wavelet coefficient after local de-noising enhancement to obtain a wide-spectrum interference pattern after local de-noising enhancement; and determining an optical path position by adopting an improved gravity center method according to the wide-spectrum interferogram after local denoising enhancement, and calculating a depth value of the to-be-measured sample. According to the method, the stripe contrast is enhanced, the noise is suppressed, and the depth measurement capability is improved at the same time.

A zero-optical-path-difference double-frequency heterodyne grating ruler comprises a light source, a signal detecting and processing system, a polarization splitting prism, a first quarter-wave plate, a rectangular prism, a second quarter-wave plate, a third quarter-wave plate, a total reflection mirror, a long-strip prism, a reference grating and a 45-degree-placed polaroid. The two measuring light paths of the system always keep zero optical path difference, so that the measuring precision can be ensured, and the environmental stability of the system is also remarkably improved. And a high-precision and high-robustness measurement scheme is provided for precision equipment such as a photoetching machine and a precision motion platform.

The utility model provides an optical path difference regulation structure lens, and relates to the field of optical lenses, the lens comprises a lens body and a lens part, the lens body comprises a convex surface and a concave surface opposite to each other; the lens part is adjacent to the concave surface of the lens body, the lens part comprises a micro-lens array, and the micro-lens array comprises a plurality of micro-lenses which are sequentially arranged to form an ultra-microstructure area; the micro lens is of a nanoscale diffraction structure and has the effective haze not exceeding 15% so as to reduce the spatial frequency and the imaging degree of incident light in the ultra-microstructure area. According to the invention, multiple functions of defocus optimization design, contrast control, spatial frequency modulation and the like are integrated; the effective defocusing amount of the ultrastructure is larger, and the ultra-low disturbance amount is achieved; and the haze of the micro lens is controlled at a nano level, so that a high-fidelity optical effect can be provided.

The present invention provides an optical interference measurement device including a light source generating measurement light over a continuous wavelength range and a measurement head optically connected to the light source, directing the measurement light toward a measurement object and receiving the measurement light reflected from the measurement object. The spectrometer outputs a first spectrum resulting from interference between the measurement light reflected from a first interface of the measurement object and the measurement light reflected from at least one second interface or reference interface of the measurement object to an evaluation device. The spectrometer includes at least one grating element for fanning out the measurement light introduced into the spectrometer according to wavelength, and a first detector array including a plurality of detector pixels onto which the fanned measurement light is directed. The first spectrum includes a series of intensity values ​​measured at the detector pixels. The evaluation device calculates the optical path difference between the first interface and the second interface or reference surface from the spectrum. The optical spectrometer further includes a second detector array onto which the fanned measurement light is directed, the second detector array also including a plurality of detector pixels. A second spectrum comprises a series of intensity values ​​measured at detector pixels of the second detector row, the first spectrum covering substantially the entire wavelength range at a first resolution and the second spectrum covering a portion of the wavelength range at a higher resolution.

A semiconductor laser (1) comprising a semiconductor body (2) with an active region (20) for generating radiation (8) and an optical interaction structure (3) with structural elements (30) is specified, wherein at least some of the structural elements (30) are arranged at different nominal center distances (35) to each other such that, during operation of the semiconductor laser (1) at a given operating point, local temperature differences in the optical interaction structure (3) reduce differences between the optical path lengths (39) that are assigned to the nominal center distances (35) of these structural elements (30). Furthermore, a method for manufacturing a semiconductor laser (1) is described.

The invention provides an optical signal synchronous calibration device and method of an optical computing system. The device comprises an optical probe array, an AI coprocessor, an optical path tuning engine and a low-speed electric feedback line, wherein the optical probe array is arranged on a chip; the optical probe array detects optical signals of wavelength channels corresponding to the plurality of optical calculation units and converts the optical signals into electric signals; the AI coprocessor drives a corresponding optical calculation unit to emit a detection pulse according to a pre-distributed time slot index variable, extracts a phase error from the electric signal and calculates a final calibration amount based on the phase error; the optical path tuning engine performs an optical path tuning operation based on the final calibration amount to calibrate an error of the corresponding optical calculation unit; and the low-speed electric feedback line transmits the electric signal to the AI coprocessor and transmits the detection pulse to the chip. According to the invention, through cooperation of spatial distributed detection and board-level centralized processing, real-time calibration in a dynamic environment is realized.

The invention discloses an optical path active vibration isolation system used in an in-situ measurement environment and an automatic calibration method, and relates to the technical field of in-situ measurement. The optical path active vibration isolation system comprises a measurement interferometer and a reference interferometer. The measurement interferometer is illuminated by a white light source through a tunable filter, the tunable filter is used for filtering light emitted from the white light source and selecting a set wavelength, so that the camera generates an interferogram generated only by the set wavelength, and light with different wavelengths sequentially passes through the tunable filter, so that the camera captures a series of interferograms with different wavelengths; the absolute optical path difference is calculated in real time by analyzing the interferogram; the reference interferometer and the measurement interferometer share the same optical path, are illuminated by an infrared super light emitting diode, and are used for observing and compensating environmental noise. According to the invention, the problem of noise interference measurement in application scenes such as large-scale manufacturing workshops is solved.

The application provides a Y-shaped thin film lithium niobate electro-optical modulator and a manufacturing method. A lithium niobate layer on an electro-optical modulator chip is etched into a corresponding curved waveguide structure, and two curved waveguide structures are symmetrically arranged on both sides of the Y-shaped waveguide structure, so that the heights of two light paths are consistent. The curved waveguide structure reduces the space size required by the waveguide while ensuring the waveguide length. For the waveguide with the same length, a chip with a smaller length can be used for mounting. The signal electrode and the ground electrode are arranged on both sides of each straight waveguide in the curved waveguide structure, the optical signal in the waveguide is modulated, and the modulation requirement of the electro-optical modulator is realized.

The invention relates to a DAS signal positioning method based on adaptive tensor decomposition and dynamic correction. The method comprises the steps of converting phase difference data into strain rate data, constructing a three-dimensional tensor based on a time domain signal of a space point, solving an optimization problem after constraint modeling, and extracting a de-noised DAS signal. Calculating an initial fault position, and calculating an actual optical path and an apparent position after temperature change based on a thermal expansion effect and a thermo-optic effect; and a dynamic correction algorithm is set, a system coordinate reference is adaptively calibrated, and a final positioning result is calculated. According to the method, original signals are separated into a low-rank background field, a sparse event field and a structured noise field through unsupervised tensor decomposition, and the defects of dependence on labeled data and insufficient complex noise separation are overcome; by establishing a temperature-optical path coupling physical model and a dynamic correction algorithm for real-time cross-correlation calibration, positioning drift caused by environmental factors is accurately compensated, and high-fidelity denoising and accurate positioning of cable line events in a complex environment are realized.

The invention discloses a method for preparing a perovskite solar cell based on a nanoimprint technology, which belongs to the technical field of solar cell devices, and comprises the following steps: preparing a PDMS (Polydimethylsiloxane) soft film with a nano conical column structure on the surface, and then carrying out thermal nanoimprint on a perovskite thin film. The nano cone-column structure can induce regular and uniform growth of perovskite grains, so that the perovskite grains are regular in size and orderly arranged, and the grain boundary density and holes are reduced; and meanwhile, the nano conical column structure on the surface of the perovskite thin film can scatter incident light to increase the effective optical path length in the device, so that the light absorption of the device is enhanced, and the efficiency and the stability of the finally obtained perovskite solar cell are remarkably improved.

The invention relates to the technical field of fluorescence detection, in particular to a three-dimensional fluorescence detection correction method based on double light sources, and the correction method comprises the following steps: obtaining double light source optical parameters, sample cell geometric parameters and original fluorescence intensity data, the geometric parameters of the sample pool comprise the length, width, height, pool wall reflection coefficient and sample attenuation coefficient of the sample pool; and constructing a light intensity distribution model in a three-dimensional space of the sample cell based on the optical parameters of the double light sources and the geometric parameters of the sample cell. According to the invention, accurate characterization of the light intensity of any spatial point in the sample cell is realized, light intensity deviation caused by various factors is quantified from the source, personalized correction is carried out on each spatial point, the influence caused by optical path difference at different positions, light source fluctuation and element error is effectively offset, and the accuracy and accuracy of the detection result are improved. The consistency of detection values of standard substances with the same concentration in different areas of the sample pool is greatly improved, and the linearity of a standard curve is remarkably optimized.

The invention discloses a self-adaptive three-beam interference super-resolution microscopic imaging system and method, a light source module generates laser which sequentially passes through a polarization beam splitting module and an electro-optic phase modulation module, three beams of laser subjected to phase modulation are output, and the three beams of laser pass through an optical path compensation module to complete optical path compensation; then the laser enters the laser polarization vector modulation module for polarization modulation, the modulated laser enters the aberration correction module through the laser beam combining module, three beams of light irradiate a sample on a displacement table after aberration correction, fluorescence excited by the sample passes through the aberration correction module again to complete aberration correction, and then an image is obtained through the filtering imaging module. And the acquisition control module synchronously controls the electro-optic phase modulation module, the laser polarization vector polarization modulation module and the aberration correction module and receives an image shot by the filtering imaging module, so that high-speed real-time super-resolution microscopic imaging and high-quality aberration correction are finally realized, the three-dimensional resolution of the image, especially the resolution along the axial direction, is improved, and the imaging quality is improved. And artifacts in the image are reduced.

The invention relates to the technical field of optics, and discloses an integrated system for monitoring a laser damage threshold so as to be compatible with two different damage mechanisms of continuous laser and pulse laser. The system includes: a focus lens driven to displace on a linear displacement stage in an optical axis direction; the first diaphragm is positioned between the sample displacement table and the focusing lens and forms an included angle with the optical axis; the light spot quality analyzer is positioned in the reflection direction of the first diaphragm; the optical path of the first diaphragm transmitted to the tested sample is equal to the optical path of the first diaphragm reflected to the light spot quality analyzer; the main controller is used for judging whether the detected sample is damaged or not based on data of the photoelectric detector in the process that the focusing lens displaces from large to small according to the light spot size of the detected sample after the output light beam of the light source is stable; and according to the stable value recorded by the power meter or the energy meter and the light spot area of the light spot quality analyzer at the damage occurrence moment, the two types of laser damage thresholds of the detected sample are determined in sequence.

The invention relates to the technical field of ultrafast laser and light quantum, and provides a single-cavity double-optical-comb absolute distance measurement system and method based on repetition frequency scanning. The system comprises a single-cavity double-optical comb system which is used for simultaneously establishing clockwise and anticlockwise propagating mode-locked pulses in an annular cavity through a bidirectional pumping source and outputting a main oscillation optical comb and a local oscillation optical comb through a polarization maintaining optical fiber coupler; a first piezoelectric ceramic and a second piezoelectric ceramic are arranged in the annular cavity, and the first piezoelectric ceramic and the second piezoelectric ceramic are adjusted through a differential driving mode so as to lock and regulate the repetition frequency difference between the main oscillation optical comb and the local oscillation optical comb; the double-optical-comb distance measuring system is used for combining the main oscillation optical comb passing through the Michelson interferometer with the local oscillation optical comb not passing through the Michelson interferometer to generate a radio frequency beat frequency signal; and calculating the real-time absolute distance of the measured target according to the optical path difference of the radio frequency beat frequency signal and the repetition frequency difference of the main oscillation optical comb and the local oscillation optical comb.

The invention discloses a method for simultaneously testing the thickness and refractive index of a material based on terahertz time-domain spectroscopy, which relates to the technical field of material testing and comprises the following steps: acquiring a reference signal and a sample signal by using a transmission-type terahertz time-domain spectroscopy system, and positioning a key pulse peak through an automatic peak value recognition algorithm; frequency domain phase information is obtained by combining fast Fourier transform, and then the phase difference between the main pulse and the echo is calculated; based on an optical path difference model, a relation equation set of the double-pulse phase difference and material parameters is established, the material thickness and the refractive index are obtained through inversion, and prior refractive index information is not needed; and finally, processing the data by adopting a local weighted regression smoothing algorithm to obtain comprehensive characterization parameters of the material. By adopting the method, high-precision, rapid and lossless thickness and refractive index measurement is realized, the applicability and the flexibility of measurement are remarkably improved, and the method has a wide industrial popularization prospect.

The invention provides a head-up display system and a vehicle, and belongs to the technical field of optics. The head-up display system comprises an image source, a first plane lens, a second plane lens and a free-form mirror. The image source includes a first display area and a second display area. The first plane lens is located on an emergent light path of the first display area, and the second plane lens is located on an emergent light path of the second display area. The optical path of light emitted by the first display area on the first plane lens is different from the optical path of light emitted by the second display area on the second plane lens. The free-form mirror is located on transmission light paths of the first plane lens and the second plane lens. Because the optical path of the light in the first plane lens is different from the optical path of the light in the second plane lens, the equivalent object distances of the first display area and the second display area are different, and the virtual image distances of two focal planes corresponding to the first display area and the second display area are different. Therefore, the head-up display system can generate two focal planes with different virtual image distances.

The invention is suitable for the technical field of optical design parameter optimization, and provides a design parameter optimization method and system for a long-optical-path gas absorption cell, and the method comprises the following steps: carrying out the theoretical verification of the feasibility of the lens parameters of a spherical reflector based on a theoretical model of a light propagation matrix, and obtaining the design parameters of the spherical reflector; determining an initial lens parameter and a key design parameter range; an optical cavity model composed of two spherical reflectors is established, and automatic ray tracing simulation is carried out according to the initial lens parameters, the key design parameter range and a preset stepping value; the simulation data are verified, the number of light spots is determined, and the optimal key design parameter combination enabling the optical path to be maximized is screened out according to the number of the light spots. The method is mainly used for designing a long-optical-path gas absorption cell in infrared absorption spectrum trace gas sensor detection, has practical significance, realizes verification of optimal design parameters, reduces development difficulty and improves development efficiency.