739 results about "Optical pathlength" patented technology

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 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 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.

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.

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 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 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 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 provides a gas saturation absorption optical path structure based on dual optical path enhancement, which belongs to the field of laser optical path design and comprises an optical fiber circulator, a gas absorption chamber and an optical fiber reflector. A first port of the optical fiber circulator is connected with a laser output optical fiber, a second port of the optical fiber circulator is connected with an input collimator of the gas absorption chamber, and a third port of the optical fiber circulator is connected with a detector and is used for providing frequency reference for gas absorption; and the optical fiber reflector is connected with the output end of the gas absorption chamber. According to the invention, the physical contradiction between the air chamber size and the optical path gain is broken through, and a compact frequency stabilization system with miniaturization and high stability is realized.

The invention relates to the technical field of physical property testing, and discloses a mobile phone appearance multi-angle automatic detection system and method based on a multi-face reflection structure, and the system comprises a panorama collection unit which obtains an original panorama image formed by a to-be-detected mobile phone through a multi-face panorama reflection mechanism; the reference data storage unit is used for storing standardized three-dimensional model data of the mobile phone to be tested; the central processing unit is used for establishing the three-dimensional model data as a space measurement reference, constructing an optical path mapping matrix according to the distribution parameters, mapping a surface grid of the three-dimensional model data to a camera coordinate system to determine geometric distortion sampling coordinates, extracting pixels to complete space topology reconstruction, and generating a standardized surface expansion view; according to the invention, nonlinear perspective distortion in reflection imaging is eliminated, tight alignment of pixel sites and physical topology is realized, and physical balance with objective scales is provided for quantitative analysis of flaws.

The invention relates to a double-optical-comb laser and a laser spectrum measurement system, and the double-optical-comb laser comprises a pumping source which is used for generating pumping light. The optical fiber amplifier is connected with the output end of the pumping source, and the output end of the optical fiber amplifier is connected with the first optical fiber coupler. The first optical fiber coupler is connected with the first mode-locked laser cavity and the second mode-locked laser cavity. An output light path of the first mode-locked laser cavity is connected with the second optical fiber coupler, an output light path of the second mode-locked laser cavity is connected with the second optical fiber coupler, and the second optical fiber coupler is used for carrying out beam combination and frequency beating on the two paths of laser. The optical path delay line is used for adjusting the laser repetition frequency difference between the first mode-locked laser cavity and the second mode-locked laser cavity. The double-optical-comb laser not only overcomes the defects that an existing double-optical-comb system is complex, expensive and inconvenient to tune, but also has the advantages of being compact in structure, high in stability, high in output pulse energy and tunable in repetition frequency difference.

The invention belongs to the technical field of terahertz, relates to terahertz communication, and particularly discloses a quasi-optical resonant cavity and a terahertz pulse compression system. According to the invention, the pulse generation module and the coupling compensation module are connected in parallel and are connected to the common reflector through the common coupler, so that function decoupling is realized. In a pulse compression stage, the common coupler introduces an incident terahertz wave beam into two optical paths, and destructive interference occurs between two paths of leakage signals by adjusting the coupling compensation module, so that zero coupling loss is realized, and the problem of large energy loss is solved. Meanwhile, the pulse generation module can independently adjust the optical path of the pulse generation module to control the pulse width, and the adjustment process does not affect the optimized interference condition, so that the high robustness of adjustment is ensured. In the output stage, energy is released by switching the state of the common coupler. Compared with the prior art, low-loss accumulation and robust pulse width continuous adjustment are realized at the same time, so that the terahertz pulse compression effect is remarkably improved.

A double optical path gas chamber, a double optical path detection system and a gas concentration detection method belong to the technical field of gas concentration detection. The gas chamber comprises first and second beam splitting prisms and first and second concave mirrors. The first and second concave mirrors are oppositely arranged and sealed to form a Helium gas cell. The center and the edge of the first concave mirror are respectively provided with a short optical path inlet hole and a long optical path inlet hole, and the center and the edge of the second concave mirror are respectively provided with a short optical path outlet hole and a long optical path outlet hole. A light beam is split by the first beam splitting prism. A short optical path light beam enters the gas cell through the short optical path inlet hole and is emitted from the short optical path outlet hole. A long optical path light beam enters the gas cell through the long optical path inlet hole and is emitted from the long optical path outlet hole after multiple reflections in the cell. The emitted long and short optical path light beams are combined by the second beam splitting prism and are emitted. The system comprises a light source, the above-mentioned gas chamber and a spectrometer. The method is realized based on the above-mentioned system. The present application simultaneously meets the detection needs of long and short optical paths, realizes ultra-low concentration detection and has an ultra-high range.

The present application relates to the technical field of optical aspheric surface, especially points to a kind of free curved surface characterization method based on CGH lens zero position compensation detection optical path, with the detection of free curved surface as the guide, based on zero position compensation detection principle, according to ray tracing method, Snell's law, diffraction principle and equal optical path principle, using the parameters required by interferometer incident wave front as plane wave, compensator as single CGH lens zero position compensation detection system indirectly characterizes free curved surface shape, by using XY polynomial and Zernike standard phase polynomial, the mathematical description of free curved surface is realized in design stage can determine its measurement scheme, and according to the characterization method self-defined a kind of aspheric surface type, called zero position free curved surface.The free curved surface characterization method improves the degree of freedom of free curved surface shape and the feasibility of zero position compensation method, reduces the detection difficulty of free curved surface shape, realizes the function of zero position free curved surface design can be detected.

The invention relates to the technical field of coherent laser radar detection and imaging, in particular to a Doppler tomography laser radar imaging device based on carrier phase noise compensation and an optimization method. Phase noise is accurately estimated through a double-reference channel structure, an image quality evaluation index is adopted as a parameter optimization basis and a compensation effect judgment standard, target echo phase noise is accurately compensated, and therefore high-resolution Doppler tomography of a high-speed spinning target at the rotating speed of 30 Hz is achieved under the condition that the optical path difference exceeds the distance of 80 times of the laser coherence length. The method is designed for the broadband characteristic of the echo signal of the Doppler tomography laser radar, and has the characteristics of high compensation precision, wide distance dynamic range, low manufacturing cost and the like.

This invention discloses a two-axis multi-frame spatial beam pointing system based on a follower mirror and its design method, belonging to the field of photoelectric tracking and aiming. The system includes an outer azimuth axis, an outer pitch axis, an inner pitch axis, an inner azimuth axis, and a follower mirror; the inner pitch axis is coaxial with the outer pitch axis and both are hollow axes; the follower mirror is mounted on the inner pitch frame, and its rotation axis is parallel to the inner azimuth axis. This invention compensates for the optical axis tilt caused by the movement of the inner azimuth axis through the following motion of the follower mirror, and establishes an optical axis offset model for parameter optimization to reduce the optical axis offset. Simultaneously, a Coudre optical path change model is established for focusing of the tracking imaging component. Compared with the traditional two-axis four-frame structure, this invention simplifies the Coudre optical path, reduces debugging difficulty, improves the optical chamber ratio, and realizes the effective application of a multi-frame structure in a spatial beam pointing system.

The invention relates to the technical field of environmental monitoring, and discloses a water quality monitoring device and method adapted to various environments, the device comprises an optical measurement unit, the optical measurement unit comprises a light source, a water sample flow cell and a spectrum detector, and two sides of the water sample flow cell are provided with at least one group of movable light windows and photoelectric positioning plates; the mechanical adjusting unit comprises a driving motor, a lead screw transmission mechanism driven by the driving motor, a light window support connected with the lead screw transmission mechanism and a position sensing module used for detecting the position of the movable support. The lead screw transmission mechanism comprises a lead screw and a movable sliding block arranged on the lead screw in a sleeving mode, and the movable sliding block is fixedly connected with the light window support. By automatically switching the optical path, the instrument can accurately measure low-concentration surface water and can also measure high-concentration sewage, so that the measuring range of single equipment is effectively expanded, and the accuracy of measured data in the whole measuring range is ensured.

In a method for measuring multilayer objects (30) with a coherence tomograph (11), measuring light is directed from an optical system (25) in an object arm (18) onto a surface of the object (30). The interference of measuring light (OL), which is reflected at an optical interface (40, 42, 44) of the object (30), with measuring light (RL), which is guided in the reference arm (16), is detected by a detector (36) and converted into electrical signals. A spectrum is generated from this by Fourier transformation, with each interference being represented by a distance peak (D1, D2, D3) in the spectrum. In a process automatically controlled by a control unit (39), this measurement is repeated several times, with the distance between the object (30) and a reference plane (52) being changed at each repetition. The axial position of the reference plane corresponds to an optical path length of the reference arm (18).By analyzing the distance peaks (D1, D2, D3) and preferably thickness peaks, which represent a distance between interfaces, a unique assignment between the distance peaks and the interfaces (40, 42, 44) is determined, so that distance values ​​can be assigned to these interfaces.

An embodiment of the present disclosure provides a pulse electron microscope device including: a pulse generator configured to emit a laser pulse; a first beam splitter configured to split the laser pulse into a first laser pulse and a second laser pulse; a second beam splitter configured to split the second laser pulse and to reflect a second-1 laser pulse; an interval controller configured to control a time interval between the first laser pulse and the second-1 laser pulse by controlling an optical path length of the first laser pulse; a column part including a photocathode, the photocathode configured to convert the first laser pulse into a first electron pulse and convert the second-1 laser pulse into a second electron pulse; and an inspection module configured to inspect electrical defects in the sample by detecting a change in potential occurring on a surface of the sample.

A spectroscopic method of estimating the cadmium concentration in an aqueous sample including: preparing at least 5 aqueous calibration samples, each calibration sample including water, a pH regulator in an amount such that each calibration sample has a pH of from 8 to 10, an equal concentration of dimethylglyoxime and dissolved cadmium in an amount of from 0 to 12 μg / mL; and, measuring over optical path length (l) the absorbance for each calibration sample of radiation (R) having a wavelength of from 520 to 540 nm, thereby generating calibration data. The method further includes: forming a treated aqueous sample; measuring over the optical path length (l) the absorbance for the treated aqueous sample of radiation (R) having a wavelength of from 520 to 540 nm; generating test data; and, estimating the concentration of cadmium in the aqueous sample from the test data and the calibration data.

The invention discloses a fine simulation method of a CdTe-based II-VI group compound thin film solar cell and a cell structure designed based on the method. According to the method, a physical model of a CdTe-based battery is established through numerical simulation, then the energy band structure of a carrier transport layer is systematically optimized, and the quantitative criteria that a hole transport layer needs to meet the requirements that the Fermi energy level is lower than that of an absorption layer and the hole transport layer has enough positive conduction band offset and an electron transport layer needs to have a wide band gap and moderate positive conduction band offset are determined. And for the optical layer, the optimal thickness of the antireflection layer is determined, the enhancement effect of the optical path gain of the textured structure on optical absorption is quantified, and the maximization of the light capture efficiency is realized. According to the method, through electrical-optical coupling simulation, the CdTe-based solar cell structure of which the conversion efficiency is remarkably improved can be accurately predicted and guided to be designed, the defects that a traditional experiment is high in trial and error cost and long in period are effectively overcome, and a reliable theoretical design and optimization tool is provided for research and development of a high-efficiency and low-cost CdTe-based solar cell.

The application discloses a ternary computing method and system based on a double-chain difference coupling principle. A difference value (XnYn) is directly generated by a forward component Xn and a reverse component Yn in a difference coupling area, forming a three-value logic {‑1, 0, +1}, and a threshold comparison circuit is omitted, and operation follows BH=Σ(XnYn)×3^n. A hierarchical logic system composed of basic operators, minimum complete operators and global operators is constructed, and arbitrary three-value logic operation is realized; a circular waveguide structure is adopted to configure an optical path difference, so that coherent light directly forms three interference states at an output end, and optical three-value logic gates and optical full adders are realized; a double-chain six-bit structure is adopted for symbol coding, a two-dimensional geometric framework is driven to generate a symbol form, and logical and geometric expression unification is realized.

The invention belongs to the technical field of laser interference precision measurement, and provides a full geometric error displacement calculation method based on non-approximate simplification of a light beam track. All optical machine geometric errors can be completely calculated, the real refraction condition can be completely calculated, no approximate error is introduced in the simplification process, and the displacement calculation process conforms to the real light beam track condition; according to the method provided by the invention, all reflection phenomena in the interferometer are simplified, parameter integration is carried out on a reflecting surface and a receiving surface of a reflected light beam, an originally complicated multi-beam calculation process is optimized, the number of parameter items required for completely describing geometric errors is reduced, and the calculation efficiency is improved. And meanwhile, the light beams which do not influence the calculation of the total optical path difference are deleted, so that the calculation efficiency is high.

The invention discloses a convex spherical lens optical axis and interferometer system optical axis alignment method, a concave spherical lens is arranged behind a convex spherical lens, the convex spherical lens and the concave spherical lens form an interference cavity at a confocal position, and the interference cavity is adjusted to zero fringes; the concave spherical mirror is moved in the direction of increasing the optical path of the optical axis, and cat eye-like stripes of the convex spherical mirror lens can be observed after the concave spherical mirror is moved to a designated position; the cat eye-like stripes of the convex spherical lens are adjusted to be concentric circles, and when the tilt term of the wave aberration of the measured phase result is approximately zero, alignment is completed. The curvature radius of the standard surface of the concave spherical mirror is larger than that of the reference surface of the convex spherical mirror. The device can align the convex spherical lens with the optical axis of the interferometer system, is not limited by the F number of the spherical lens, and has the advantages of simple structure and high measurement precision.

The application discloses a high-resolution oblique-axis optical lens, comprising, from the object side to the image side, a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a protective glass and an image sensor; the first lens is a filter; the second lens is a biconvex spherical lens with positive focal power; the third lens is a spherical lens with negative focal power; the fourth lens is a spherical lens with positive focal power; and the fifth lens is a biconcave spherical lens with negative focal power. The technical scheme balances and corrects optical aberrations of all levels by reasonably distributing the focal power of the lenses, reasonably matching the optical materials and shapes, and utilizes the cylindrical lens to correct astigmatism caused by the optical path of the meridian arc vector plane of the protective glass, so that the advantages of large target surface, low distortion, ultra-short object distance, high resolving power and the like of the lens are achieved.