21 results about "Fizeau interferometer" patented technology

The invention provides a double-state interference morphology measurement method and system for a discontinuous precision surface, and belongs to the technical field of optical precision measurement. Based on a Fizeau interferometer, interference images in a focusing state and an out-of-focus state are respectively acquired, two-dimensional structure information and height information of a sample with a discontinuous precise surface are respectively extracted, and two-state data fusion is carried out, so that three-dimensional morphology reconstruction is realized. The method breaks through the limitation of the optical diffraction limit on the resolution, avoids the failure problem of a traditional phase unwrapping algorithm at a discontinuous boundary, remarkably enhances the environmental interference resistance, improves the calculation efficiency, is suitable for high-precision surface measurement of a vacuum chuck and the like with a large number of discontinuous characteristics, and has a wide application prospect. And a reliable solution is provided for high-end manufacturing quality control.

An optical sensor for measuring physical parameters in harsh environments and methods of making and using the same are disclosed. An optoelectronic system for measuring a physical parameter includes two narrowband light sources having different peak frequencies coupled together with a coupler into a combined light. The combined light is divided into a first Fabry-Perot interferometer and a second Fabry-Perot interferometer, the first Fabry-Perot interferometer being configured to be exposed to temperature and another physical parameter, and the second Fabry-Perot interferometer being configured to be exposed only to temperature. The system further comprises a first optical detector and a second optical detector arranged to receive light reflected from the cavities of the first and second Fabry-Perot interferometers, respectively, through a combined optical path comprising a lens and / or mirror and the Fizeau interferometer. The processor is configured to analyze data received by the first optical detector and the second optical detector and calculate temperature values and physical parameters.

A kind of lidar technology for atmospheric waveguide fast measurement, temperature and humidity profile, the key factor of atmospheric waveguide, can be measured simultaneously, the device includes laser emission module: 822nm online seed laser, 822nm offline seed laser, 1064nm pump laser, laser frequency locking module, optical parametric oscillator, acoustooptic modulator, frequency doubling module and emission optical assembly;Echo receiving module: optical receiving telescope and optical lens assembly, F-P filter, polarization light splitting prism, iodine molecular absorption cell, Fizeau interferometer and photodetector;Data acquisition and processing module.The present application fuses differential absorption lidar and two detection systems based on interferometer high spectral lidar, adopts seed injection optical parametric oscillator laser technology, obtains high frequency stability 822nm laser to realize atmospheric humidity profile fast measurement, remaining 532nm laser realizes atmospheric temperature profile fast measurement, finally inverts atmospheric waveguide parameter, realizes atmospheric waveguide efficient and accurate measurement.

This invention discloses a method for measuring the wavelength of low-coherence lasers using a synthetic Fizeau interferometer cavity. The method involves acquiring the interference fringes and extracting the initial phase of each actual Fizeau interferometer cavity with different free spectral ranges (FSRs) that meet the coherence length requirements of the low-coherence laser to be measured. Based on the FSRs and initial phases of each actual cavity, a synthetic Fizeau interferometer cavity with a FSR smaller than that of the physical cavities is constructed to obtain the synthetic free spectral range and synthetic initial phase. The interference order of the synthetic cavity is then determined by combining the input estimated wavelength or frequency, and wavelength refinement is performed to finally obtain the measurement wavelength. This invention does not limit the specific optical path structure or detector arrangement, and can effectively overcome the limitation of low-coherence laser coherence length on the accuracy of Fizeau wavelength measurement without increasing the optical path difference of the actual Fizeau interferometer cavity or reducing the fringe signal-to-noise ratio.

The application discloses a wide-band wavelength meter based on a multi-stage Fizeau interference cavity, which comprises a fiber port, a concave mirror, a first mirror, a Fizeau single-stage cavity, a first cylindrical lens and a first linear array detector which are coaxially arranged along a first sub-light path in sequence, and a second mirror, a Fizeau multi-stage cavity, a second cylindrical lens and a second linear array detector which are coaxially arranged along a second sub-light path in sequence. The light emitted by the fiber port becomes parallel light after passing through the concave mirror, and then enters the Fizeau single-stage cavity and the Fizeau multi-stage cavity to interfere after passing through the first mirror and the second mirror respectively. The light emitted from the back bottom surface of the interference cavity converges energy through the first cylindrical lens and the second cylindrical lens and then forms interference fringes on the first linear array detector and the second linear array detector. Compared with a traditional wavelength measurement system, the application has a simpler and more stable structure, and can realize wide-band wavelength high-precision measurement through partition coating.

The invention discloses a wavelength tuning phase-shifting interference method assisted by element absorption spectral lines and a resonant cavity. The wavelength tuning phase-shifting interference method comprises the following steps: establishing a system comprising a Fizeau interferometer, an external cavity tunable laser, an element absorption cell and the resonant cavity; phase-shifting interference measurement is carried out by using a sweep-frequency light source in cooperation with a Fizeau interferometer, and the change of an interference image is recorded by a high-speed CMOS camera; recording the spectral line of the light source scanning through the rubidium absorption spectral line and the resonant cavity; and calibrating the relationship between the scanning time and the scanning frequency according to the measurement spectral line, determining the phase change quantity according to the wavelength, selecting an interferogram corresponding to the phase change quantity according to the requirement of a phase shift algorithm, and calculating to realize high-precision detection of the surface type. According to the method, the phase shift is determined through high-precision wavelength determination, and the detection precision is improved. Meanwhile, due to high-precision wavelength resolution, the method can be applied to wavelength tuning phase-shifting interference with an ultra-long detection distance.

This invention discloses a method for calibrating the cavity length of a Fizeau wavelength meter interferometer cavity, comprising: acquiring interference fringe patterns of two lasers of known wavelengths passing through two Fizeau interferometer cavities, and extracting interference signals I1 and I2; extracting the fractional initial phase of the two interference fringes and the ideal cavity length h0 and the two known wavelengths, and calculating the interference order of the fringes at the initial position and rounding it; calculating the cavity lengths h1 and h2 using the above parameters, and constructing a system of equations with the relationship between the actual cavity length and the actual cavity length, and solving for the initial calibration cavity lengths h′1 and h′2; replacing h0 with h′1 and h′2 and repeating the above process to solve for the cavity length to obtain the calibration cavity length h. cal1 and h cal2 The obtained h cal1 and h cal2 After subtracting from the arrays h′1 and h′2, perform least squares calculations to find the cavity length value corresponding to the minimum value in each group, and then calculate the average to obtain the final calibrated value h of the cavity length. cal This method is simple and fast, and the calibrated cavity length has high accuracy, ensuring the accuracy of wavelength measurement by the Fizeau wavelength meter.

The invention relates to the technical field of optical measurement and intelligent control, and particularly provides an interferometer automatic alignment method and system based on physical enhancement deep learning, and the method comprises the following steps: S1, constructing a high-fidelity time-varying simulation environment; s2, constructing a multi-granularity unified action space; s3, feature expression of a physical sensitive area in the interference fringes is enhanced in a self-adaptive mode; s4, sensing and counteracting system errors caused by temperature drift and mechanical vibration in real time; s5, the strategy generalization ability is improved; s6, deploying the trained strategy to a Fizeau interferometer control system, and realizing high-robustness automatic pre-alignment closed-loop control; the system comprises a high-fidelity time-varying physical simulation module, a multi-granularity adaptive control module, an environment disturbance feedforward compensation module, a domain randomization training module and a system interface and safety monitoring module. According to the method, high-precision, high-efficiency and high-robustness automatic alignment without a precise system model can be realized, and the automation level of optical detection and the industrial field applicability are remarkably improved.

This invention relates to the field of optical measurement and calibration technology, and in particular to a method, medium, and apparatus for calibrating a plane reference mirror in a vertical interferometer. The method involves placing a calibration plate as a temporary mirror under test in the measurement optical path of a vertical Fizeau interferometer. At at least one measurement point, the calibration plate is continuously rotated around its own rotation center. The rotation centers at each measurement point are offset from the central optical axis of the plane reference mirror and equidistant. Multiple frames of surface shape measurement data are collected at each measurement point, and the absolute surface shape error of the plane reference mirror is obtained by arithmetic averaging of all measurement point data. This method, through the specific offset measurement point settings, systematically changes the spatial orientation of the calibration plate at different points, offsetting central symmetry errors and suppressing asymmetric errors and random noise. It achieves high-precision and robust absolute calibration without the need for complex algorithms. Compared with traditional methods, it combines accuracy, efficiency, and practicality, is suitable for various application scenarios, and provides a framework for subsequent efficiency optimization.

The application discloses a kind of automatic measuring device and detection method of lens center thickness, including spectral confocal system and Fizeau interference system, spectral confocal system includes light source, confocal pinhole and optical system, and optical system includes first half reflection half permeation lens, chromatic focus lens and spectroscope;Fizeau interference system includes Fizeau interferometer and computer, and Fizeau interferometer includes laser emission component and first imaging mirror, reference mirror, second beam expander, second half reflection half permeation lens, second imaging mirror and CCD camera.The lens center thickness with error component is measured using spectral confocal system, the physical translation error component, tilt error component of the lens to be measured are detected in real time using field calibration and Zernike wave surface fitting in Fizeau interference system, and the measured lens center thickness is automatically corrected using error correction formula, and then the lens center thickness is accurately measured, which can greatly save labor and time cost, and improve detection efficiency.

The present application relates to the field of optical technology, a Fizeau interferometer with high interference contrast by adapting the reflectivity of detection surface, comprising laser light source, 1 / 2 wave plate, converging lens group, illumination diaphragm, polarization beam splitter, collimating lens group, Faraday rotator and polarization reference mirror group arranged in sequence along the first light path direction; further comprising imaging diaphragm, imaging lens group and ccd camera arranged in sequence along the second light path direction; the 1 / 2 wave plate is installed on a rotating mechanism for adjusting the fast axis angle; the first light path direction is the same as the transmission optical axis direction of the polarization beam splitter, and the second light path direction is the same as the reflection optical axis direction of the polarization beam splitter. The maximum light intensity of the interference signal is jointly adjusted by the output power of the laser light source and the 1 / 2 wave plate; the contrast of the interference signal is adjusted by the Faraday rotator.

The invention discloses an orthogonally-arranged double-path laser Fizeau interferometer, which comprises an interference channel A, an interference channel B and a data processing unit which are orthogonally arranged, and is characterized in that the interference channel A is used for acquiring measurement data of a first view field; the interference channel B is used for acquiring measurement data of a second view field; meanwhile, the measured curved surface on the measuring station is measured from different directions; the data processing unit is configured to receive and synthesize the measurement data of the first field of view and the second field of view to generate a synthesized field of view, and calculate contour parameters of the measured curved surface based on the synthesized field of view. The interference channel A and the interference channel B are orthogonally arranged in space, so that a measured curved surface can be measured from two mutually perpendicular directions at the same time, the effective measurement view field of the system is remarkably expanded, the problem of fitting morbidity caused by local concentration or lack of data in traditional single-view-field measurement is solved, and the measurement accuracy is improved. Therefore, the convergence speed and the numerical stability of fitting algorithms such as the least square method are improved.

The invention discloses an interference measurement device and method adopting a spectrum regulation and control light source. The device comprises a spectrum regulation and control light source, an optical fiber, a Fizeau interferometer module, an imaging objective lens and an area array detector. The time change rule of the spectrum output by the sweep frequency laser light source is accurately controlled, so that a programmable spectrum regulation and control track is formed in a single-frame exposure or continuous multi-frame acquisition process, and equivalent phase shift control and optical path difference modulation are realized under the condition that mechanical phase shift or optical path scanning is not needed. The acquired interference signal is processed by a phase shift algorithm, and the phase distribution or the surface appearance of the sample to be detected can be recovered. According to the method, the spectrum regulation and control function can be designed according to different measurement tasks, dynamic adjustment of the coherent envelope position is achieved, the problem of multi-surface interference is effectively avoided, optical path matching is achieved without a mechanical positioning mode, and the method has the advantages of being high in precision, rapid in measurement, easy and convenient to debug and the like. The method is suitable for the high-precision interference measurement field such as optical element surface appearance detection, transparent sheet thickness measurement and precise wavefront test.

The invention discloses a splicing interference measurement system and method for monitoring and compensating relative angles of double reference mirrors, a Fizeau interferometer is arranged on one side of the upper end of a marble air floating platform, and a reflector to be detected is arranged on the other side of the upper end of the marble air floating platform; a first plane reference mirror and a second plane reference mirror are arranged above and below a reflector to be detected respectively, a small yz-direction rotary table is arranged at the lower end of the second plane reference mirror, a small xz-direction rotary table is arranged at the lower end of the small yz-direction rotary table, a large yz-direction rotary table is arranged at the lower end of the small xz-direction rotary table, and a large xz-direction rotary table is arranged at the lower end of the large yz-direction rotary table. An x-direction linear guide rail is arranged at the lower end of the xz-direction large rotary table, the lower end of the reflector to be detected is connected with the upper end of the yz-direction large rotary table through a second supporting frame, and the upper end of the first plane reference mirror is connected with the upper end of the marble air floating platform through a first supporting frame. The two plane reference mirrors are adopted to measure the actual deflection angle difference, and angle error accumulation caused by program calculation each time is eliminated.

The application discloses an online self-calibration measurement method of a liquid crystal polarization phase-shifting Fizeau interferometer, which comprises the following steps: firstly, a software controls the voltage of a liquid crystal variable retarder and synchronously collects a series of phase-shifting interferograms at a CCD end; secondly, all the interferograms are preprocessed according to the light intensity variation of the series of phase-shifting interferograms to remove background information and normalize modulation degree; and finally, the results after column average of all the interferograms are subjected to Hilbert transform, and the phase-shifting amount of each interferogram relative to the first interferogram is calculated according to the obtained phase. The method can realize online in-situ self-calibration in the Fizeau interferometer quickly, improve the precision of phase-shifting and interference measurement, and can be used for the interferogram with few fringes.

The application discloses a kind of relative angle monitoring and compensation of double reference mirror splicing interferometry system and method, Fizeau interferometer is arranged in the upper end side of marble air float platform, to be detected mirror is arranged in the upper end other side of marble air float platform, the upper and lower of to be detected mirror are respectively equipped with plane reference mirror one and plane reference mirror two, the lower end of plane reference mirror two is equipped with yz direction small turntable, the lower end of yz direction small turntable is equipped with xz direction small turntable, the lower end of xz direction small turntable is equipped with yz direction large turntable, the lower end of yz direction large turntable is equipped with xz direction large turntable, the lower end of xz direction large turntable is equipped with x direction linear guide, the lower end of to be detected mirror is connected with the upper end of yz direction large turntable by support frame two, the upper end of plane reference mirror one is connected with the upper end of marble air float platform by support frame one.The application measures actual deflection angle difference using two plane reference mirrors, eliminates angle error accumulation caused by each program calculation.

The application discloses a low-coherence laser wavelength measurement method using a synthetic Fizeau interference cavity. The method is aimed at at least two actual Fizeau interference cavities with different free spectral ranges (FSRs) and meeting the coherence length requirements of a low-coherence laser to be measured, interference fringes of the actual Fizeau interference cavities are acquired respectively and fringe initial phases are extracted; based on the free spectral ranges and the fringe initial phases of the actual cavities, a synthetic Fizeau interference cavity with a free spectral range smaller than that of the actual cavities is constructed, a synthetic free spectral range and a synthetic initial phase are obtained; then the synthetic cavity interference order is determined in combination with an input estimated wavelength or frequency, and wavelength refinement is performed, and finally the measurement wavelength is obtained. The application does not limit specific optical path structures and detector arrangement modes, can effectively break through the limitation of the coherence length of a low-coherence laser on the Fizeau wavelength measurement precision without increasing the optical path difference of the actual Fizeau interference cavities and without reducing the signal-to-noise ratio of the fringes.

This invention relates to the field of optical interferometry, specifically to a method for measuring the interferometric surface shape of a binary diffraction grating by separating the upper and lower surfaces. This method addresses the problem that traditional Fizeau interferometry cannot achieve independent measurement of each surface when measuring periodic diffraction structures due to fringe aliasing, phase jumps, and signal mixing. The method is based on acquiring a phase-shifted interferogram sequence using a standard Fizeau interferometer. After suppressing diffraction noise and reconstructing clear fringes using a three-dimensional Fourier transform and spatial low-pass filtering, a phase-shifting algorithm is used to extract the continuous phase. To separate the upper and lower surfaces, the zero-frequency component in the time domain is further extracted to obtain a reflectivity distribution map, and a segmentation mask is automatically generated based on its step intensity characteristics, ultimately achieving independent phase separation and surface shape reconstruction for each surface. This invention requires no changes to the interferometer hardware, effectively overcomes the difficulties of fringe aliasing and phase unpacking, achieves high-precision and stable measurement of binary diffraction gratings, and possesses strong noise resistance and good engineering applicability.

The invention discloses an atmospheric temperature profile detection laser radar system and method based on a Fizeau interferometer. The system comprises a laser emission module, an emission optical assembly, an echo receiving module and a data acquisition and processing module. According to the invention, atmospheric temperature inversion is realized based on the relation between the spectral characteristics of Rayleigh-Brillouin scattering and atmospheric physical parameters: laser is emitted to the atmosphere by using a laser radar and echo signals are received; a reflection-type Fabry-Perot interferometer is designed to eliminate aerosol mie scattering interference in echo signals, and meanwhile, polarization information of aerosol is collected; the residual Rayleigh-Brillouin scattering spectral signals are subjected to hyperspectral detection imaging through a Fizeau interferometer and a multi-channel photomultiplier tube PMT array; and the Levenberg-Marquardt (LM) algorithm is adopted to obtain the atmospheric temperature profile information in a high precision manner.

The invention discloses an unknown free-form surface interference detection device for rapid recovery of sparse fringes, and relates to the field of optical detection. Comprising a polarization principle-based adaptive interference detection system and an adaptive aberration compensation system. According to the adaptive interference detection system, a commercial Fizeau interferometer, a deformable reflector (DM) and a partial zero compensation mirror (PNL) are integrated, the interferometer is endowed with flexible aberration compensation capability on the basis of ensuring high-robustness retrieval of wavefront data, and the flexible detection level of the interferometer is remarkably improved; the adaptive aberration compensation system is composed of the convolutional neural network and the ray tracing technology, wavefront aberration prediction is carried out on the incomplete interferogram through the convolutional neural network, the needed aberration compensation amount is solved in combination with the ray tracing technology, sparse fringe rapid recovery without iteration is achieved, and the adaptive aberration compensation method has the advantages of being simple in structure and convenient to operate. The limitation problems of low convergence speed, long time consumption and high manual dependence degree of a traditional algorithm are effectively solved.

The invention relates to the technical field of Fizeau wavemeters, and provides a Fizeau interferometer waveform correction device and method based on a long short-term memory network. The device comprises a light source module used for generating a light beam, the light beam is divided into two paths of light through a beam splitter, and one path of light enters a wavelength calibration module to obtain standard wavelength data; the other path of light enters the Fizeau interferometer to obtain original wavelength data; and the data processing module is internally provided with a long short-term memory network and is used for receiving the standard wavelength data and the original wavelength data, designing a composite loss function to optimize network parameters and outputting a corrected Fizeau interferometer waveform. According to the invention, the optical processing precision dependence can be reduced, and the signal processing robustness is improved.