40 results about "Fizeau interferometer" patented technology

According to the measuring equipment provided by the invention, based on the light path design of double Fizeau interferometers, the third quarter-wave plate is arranged between the first PBS beam splitter prism and the first protective glass, and the fourth quarter-wave plate is arranged between the second PBS beam splitter prism and the second protective glass; the first protection glass reflects part of incident light beams to the third quarter-wave plate and then reflects out of a light path after passing through the first PBS prism, and the second protection glass reflects part of incident light beams to the fourth quarter-wave plate and then reflects out of the light path after passing through the second PBS prism. Therefore, light reflected by the paired protective glass is prevented from entering the interferometer on the side, crosstalk is filtered out, and the measurement precision is ensured.

The invention provides an optical element laser thermal effect and light beam quality integrated measurement device and method, and the device combines key assemblies, such as a pump laser, a real-time power monitoring module, an energy transmission optical fiber, a multi-surface reflector, a beam splitter, a monochromatic optical filter, a CCD camera, an infrared thermal imager, a blackbody radiation calibration module, a Fizeau interferometer and the like. And the thermal effect of the transflective element can be measured at a specific angle. The device combines pump light and test light into one beam through the beam combiner and irradiates the surface of a sample at the same time, after transmission, the beam splitter divides the laser into two paths, one path is used for collecting far-field light spots to calculate the quality of the light beams, the other path forms an interference image to calculate thermal distortion, and meanwhile, the thermal infrared imager monitors the temperature of the sample. According to the invention, non-contact lossless integrated synchronous measurement is realized with high integration level and high flexibility, the device is suitable for temperature, thermal distortion and light beam quality measurement of an optical element under continuous or pulse laser, and thermal response characteristics of a sample are comprehensively and accurately evaluated.

The measuring equipment provided in the present application is based on the optical path design of the double Fizeau interferometer. A third quarter-wave plate is arranged between the first PBS beam splitter prism and the first protective glass, and a fourth quarter-wave plate is arranged between the second PBS beam splitter prism and the second protective glass. The first protective glass reflects part of the incident light beam to the third quarter-wave plate, and then reflects it out of the light path after passing through the first PBS beam splitter prism. The second protective glass reflects part of the incident light beam to the fourth quarter-wave plate, and then reflects it out of the light path after passing through the second PBS beam splitter prism, so as to prevent the light reflected by the protective glass on the opposite side from entering the interferometer on this side, filter out crosstalk, and ensure measurement accuracy.

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.

The present invention relates to a wafer thickness measurement device and method based on a double Fizeau interferometer. The device includes an environment detection system and a central processing unit. The environment detection system is used to measure the environmental parameters around the first reference mirror and the second reference mirror. The central processing unit is used to perform Zernike fitting on the cavity topography, decompose the cavity topography into a first-order topography and a higher-order topography greater than the first order. Using the environmental parameters measured under different environments, a relationship formula between the environmental parameters and the reference mirror tilt coefficient is constructed by fitting. The first-order topography correction amount during measurement is calculated using the relationship formula, and the original first-order topography is replaced with the first-order topography correction amount, and then the thickness of each coordinate point of the wafer is calculated. By real-time monitoring the tilt changes of the two reference mirrors through the environment detection system, the tilt amount of the absolute thickness of the wafer is compensated, thereby achieving an accurate reconstruction of the absolute thickness distribution of the wafer.

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 large-angle Fizeau interferometer wavelength measurement device, comprising an optical fiber port, an off-axis parabolic mirror, a Fizeau interferometer, a cylindrical mirror, and a linear CCD array, all coaxially arranged along the main optical path. A laser beam is incident through the optical fiber port onto the off-axis parabolic mirror for collimation, resulting in parallel light with a specific spot size. The collimated light is then incident on the Fizeau interferometer, and the light reflected from the Fizeau interferometer passes through the cylindrical mirror onto the linear CCD array, forming interference fringes. The cylindrical mirror vertically constricts the interference fringes reflected from the Fizeau interferometer, increasing the intensity of the final interference fringes incident on the linear CCD array. The Fizeau interferometer used in this invention avoids the influence of reflected light from unwanted reflective surfaces on the final interference fringes, improving the final wavelength measurement accuracy. The Fizeau interferometer composed of angled wedge-shaped window mirrors eliminates the need for coating, resulting in a wide usable wavelength range.

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 discloses a dual-Gaussian imaging system suitable for Fizeau interferometers. It includes an aperture stop, a dual-Gaussian imaging lens group, and a high-resolution camera arranged coaxially in sequence. The target surface protective glass of the high-resolution camera is replaced with anti-reflective glass. After the target beam is converged by the aperture stop, it is imaged onto the target surface of the high-resolution camera by the dual-Gaussian imaging lens group. The dual-Gaussian imaging lens group includes a first lens, a second lens, a third lens, and a fourth lens arranged coaxially in sequence, forming a symmetrical dual-Gaussian lens group structure. This invention employs a dual-Gaussian lens structure, which facilitates the correction of transverse aberration. The dual-Gaussian structure replaces the old-fashioned two-element plano-convex lens and three-element Cooke lens, correcting field curvature and distortion, optimizing wavefront aberration, widening the aperture stop, reducing the F-number of the imaging lens group, and improving MTF performance.

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 invention discloses a grinding processing method of a Porro prism, which comprises the following steps: step 1, rough grinding processing: selecting a rectangular original block, repairing a 90-degree angle of a raw material block to be within 2 minutes, grinding a first reflecting surface A and a second reflecting surface D on the raw material by leaning against the body, wherein the size of the first reflecting surface A and the second reflecting surface D is 0.3 mm greater than that of a finished product, and the angle error is within 5 minutes; secondly, accurate grinding and polishing machining is conducted, specifically, the size error is controlled within 0.005 mm after the four machining faces of the roughly-ground formed part are ground through a plane accurate grinding machine, and polishing machining is conducted, specifically, the four faces subjected to accurate grinding machining are subjected to plane grinding and polishing; step 3, cleaning the ground and polished part after the part is discharged from the disc, performing ultrasonic cleaning, and wiping the part to be clean; and 4, a laser Fizeau interferometer is used for conducting surface type inspection on the four polished surfaces, a dial indicator is used for inspecting the size, a comparison goniometer is used for inspecting the angle, and the part is submitted for inspection after being qualified.

The present invention discloses a wavelength meter and its measurement method. The wavelength meter includes: a beam splitter, which splits the laser to be measured into two paths, which are input to a Fizeau interferometer and an FP interferometer respectively; a Fizeau interferometer, which is used to output a rough measurement wavelength range; an FP interferometer, which is used to perform precise wavelength measurement within the rough measurement wavelength range; a first photodetector and a second photodetector, which respectively detect the transmitted light intensity and the reflected light intensity of the FP interferometer; a tuning device, which is used to adjust the cavity length of the FP interferometer or the frequency of the laser to be measured to eliminate multi-value ambiguity in wavelength measurement; and a control and calculation unit, which determines the unique wavelength value of the laser to be measured based on the light intensity ratio of the first photodetector and the second photodetector, the adjustment amount of the tuning device, and a pre-calibrated response curve. This method can achieve a measurement range of hundreds of THz with an accuracy of 10 ‑9 It can measure wavelengths above 100 nm and is less sensitive to ambient temperature and vibration than the Fizeau interferometer.

The invention relates to the technical field of laser detection, in particular to a laser wavelength measurement system based on a Fizeau interferometer, which comprises a Galileo beam expanding module, an attenuation piece, a Fizeau interference module, a linear array CMOS camera and a data processing module, wherein the Galileo beam expanding system is composed of a double-agglutination achromatic negative lens and a double-agglutination achromatic lens, the five-time beam expanding function is achieved on incident laser, and the influence of chromatic aberration in the broadband range is reduced; to-be-detected laser passes through the beam expanding system, passes through the attenuation piece and then enters the Fizeau interference module to be interfered, and an interference image is collected by the photoelectric imaging sensor and then is subjected to subsequent operation by the upper computer; the invention can provide a laser wavelength measuring device which is free of a moving device inside, wide in measuring range and low in cost for a laser in a wave band range of 633-852 nm.

The invention relates to the technical field of lens laser detection, in particular to a spherical lens surface shape automatic detection device based on a Fizeau interferometer, which comprises the Fizeau interferometer, an automatic feeding device and an automatic discharging device are respectively arranged on the two sides of the Fizeau interferometer, the Fizeau interferometer is connected with a vertically arranged electric track through a connecting seat, and the connecting seat is connected with the automatic feeding device. A lens clamping seat is arranged below the Fizeau interferometer, the lower end of the electric track is connected with a bracket, the bracket is connected with a driving shaft fixedly connected with the lens clamping seat through a rotary damper, and the side face of a connecting seat is connected with a transmission assembly in transmission with the driving shaft; in the up-and-down moving process of the Fizeau interferometer, the lens clamping seat can be automatically driven to turn over through the transmission assembly, so that the two side faces of the lens can be conveniently and rapidly detected, and the convenience of lens detection is improved.

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 present invention discloses an iterative correction method for return error in spherical and planar measurement using a Fizeau interferometer. The method comprises the following steps: first, determining the order of the return error according to the type of the measured object and determining the number q of the sensitive factor matrix; changing the posture of the measured object q times and measuring the phase result each time; then, calculating the tilt amount in the result of the measured phase result, substituting the result into the equation group to calculate each sensitive factor matrix and the corrected phase; then calculating the local tilt amount caused by the surface shape in the x and y directions according to the corrected phase, updating the tilt amount, and re-substituting the result into the equation group to calculate each sensitive factor matrix and the corrected phase; repeating the above process until the iteration converges to obtain the sensitive factor matrix and the corrected phase result. The present invention can correct the return error caused by non-zero position measurement in spherical and planar measurement using a Fizeau interferometer, without the need to model the internal structure of the interferometer, and is simple, efficient, and has a wide range of applications.

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 present invention discloses an interferometer device for high-precision wavelength measurement, which comprises a housing and an optical mechanism arranged inside the housing. The optical mechanism includes an independent interferometer and a combined interferometer arranged in parallel from left to right. The independent interferometer includes a rear cavity mirror of the No. V interferometer and a front cavity mirror of the No. V interferometer arranged in front of it. The combined interferometer includes a combined rear cavity mirror and a front cavity mirror of the combined interferometer arranged in front of it. The combined rear cavity mirror includes a rear cavity mirror of the No. I interferometer, a rear cavity mirror of the No. II interferometer, a rear cavity mirror of the No. III interferometer, and a rear cavity mirror of the No. IV interferometer stacked in sequence from bottom to top. The present invention provides an interferometer device for high-precision wavelength measurement, integrates five Fizeau interferometers in a sealed cavity, simplifies the measurement optical system, and at the same time proposes a simple wavelength measurement method, which can achieve a wavelength measurement accuracy of 10-7.

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.

A low-coherence Fizeau interferometer includes a first beamsplitter, a test arm and a reference arm, the first beamsplitter splits light into a first portion of light directed to the test arm and a second portion of light directed to the reference arm, and an imaging arm comprising a first collimating lens, a flat reference surface, and a test element. The test arm focuses the first portion of light at a first focal point, such that a virtual image of the first focal point appears at a focal point of the test element. The reference arm focuses the second portion of light at a second focal point, the first collimating lens collimates the light that then reflects off the flat reference surface. The second beamsplitter directs the first portion of light to reflect off the test element. The reflection of the first and second portion of light form an interference pattern.

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 present invention belongs to the field of optical metrology and testing technology and discloses an ultraviolet to short-wave infrared Fizeau interferometer laser wavelength meter, comprising: an optical fiber base, a collimating mirror, a plane mirror group I, a plane mirror group II, a band selection aperture, an ultraviolet-visible interferometer cavity, a short-wave infrared interferometer cavity, an ultraviolet-visible cylindrical mirror, a short-wave infrared cylindrical mirror, a baffle I, a baffle II, an ultraviolet-visible array CCD, a short-wave infrared array CCD, and a computer. The present invention solves the problem that laser wavelengths in the 192nm to 2100nm band cannot be measured on a single wavelength meter, improves the measurement speed of laser wavelengths in different bands, reduces costs, and has broad application prospects.

The invention relates to the technical field of optical measurement calibration, in particular to a plane reference mirror calibration method for a vertical interferometer, a medium and equipment. The method comprises the steps that a calibration plate is arranged on a measurement light path of a vertical Fizeau interferometer to serve as a temporary measured mirror, the calibration plate is driven to continuously rotate around the rotation center of the calibration plate at at least one measurement point position, the rotation center of each measurement point position and the central optical axis of a plane reference mirror are arranged in an off-axis mode, the distances are equal, and multi-frame surface shape measurement data are collected at each measurement point position; and arithmetic averaging is carried out on all measurement point data to obtain the absolute surface shape error of the plane reference mirror. According to the method, through specific off-axis measurement point position setting, spatial orientations of different point positions of a calibration plate are systematically changed, centrosymmetric errors are offset, asymmetric errors and random noise are inhibited, a complex algorithm is not needed, and high-precision and high-robustness absolute calibration is realized. Compared with a traditional method, the method has precision, efficiency and practicability, is suitable for various application scenes, and provides a framework for follow-up efficiency optimization.

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.