Method for adjusting Doppler asymmetric spatial heterodyne interferometer

Abstract

A method for adjusting a Doppler asymmetric spatial heterodyne interferometer belongs to the technical field of interference spectrums, and aims to solve the problem that an existing Doppler asymmetric spatial heterodyne interferometer is large in overall adjustment error, and the method comprises the steps that a front lens, a rear lens and a collimating lens are installed and corrected in parallel, and a centering instrument detects the adjustment state of the lenses; the reflex mirror is installed and adjusted by using the reference reflector; after the calibration is completed, carrying out complete machine assembly and calibration on a reflex mirror assembly, a beam splitter prism, an optical filter, an interference module and a camera on a load mounting plate, finely adjusting the reflex mirror assembly to ensure that the signal light enters a light path in a collimating manner, and then adjusting a collimating lens reflector to ensure that the calibration light enters the light path in a parallel manner; and adjusting the camera position to obtain clear imaging. By adopting the system integrated installation and adjustment method, the front lens, the rear lens and the collimating lens can be installed and adjusted in parallel, the installation and adjustment efficiency is improved, the whole machine installation and adjustment are carried out with the other parts after the installation and adjustment are completed, an optical path is integrally designed to ensure that optical axes of all elements are not deviated, and the influence of installation errors is reduced, so that high-quality interference fringes are obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of interference spectroscopy, and in particular relates to an installation and adjustment method of a Doppler asymmetric spatial heterodyne interferometer. Background Art

[0002] Atmospheric wind plays an important role in atmospheric dynamics and energetics. The neutral wind in the thermosphere affects the interaction between neutral molecules and plasma, and is related to space weather forecasting and modern satellite communications. Passive wind field detection technology is used to observe the Doppler shift of the natural atmospheric radiation spectrum. In the middle and upper atmospheric regions, airglow spectra emitted by oxygen atoms and oxygen molecules can be found. The Doppler shift of these spectra can be used as a target for measuring the neutral wind in the thermosphere. For the detection of neutral wind fields in the middle and upper atmospheric layers, traditional optical interferometers are currently used more, such as wide-angle Michelson interferometers and Fabry-Robert interferometers, but they are greatly affected by mechanical control and processing technology. Therefore, it is necessary to explore new interferometric spectroscopy technology. The Doppler asymmetric spatial heterodyne interferometer is a Michelson interferometer that is further improved on the basis of the principle of spatial heterodyne spectral interferometry technology. It has the characteristics of large field of view, ultra-high resolution, high throughput, no moving mirrors, simple process, light weight and small size.

[0003] The Doppler asymmetric spatial heterodyne interferometer can detect multiple spectral lines at the same time. The atmospheric airglow enters the system from the front mirror group, and after being split by the beam splitter, a phase difference is generated through the field widening prism. The airglow is incident on the blazed grating and diffracted back. The propagation direction of the two returning wavefronts has a small angle with the optical axis, forming spatial interference fringes. The interference fringes containing height profile information can be detected at one time by the array detector, and the atmospheric wind field information can be finally obtained through phase inversion.

[0004] In the process of obtaining atmospheric wind field information, interferometers play a vital role. To obtain clear and neat interference fringes, it is necessary to strictly control the installation and adjustment of the interferometer and design the installation and adjustment workpiece to reduce the subsequent impact on the inverted wind speed error.

[0005] The Chinese patent publication number is "CN 107238438 A", and the patent name is "Assembly and Adjustment Method of Doppler Differential Interferometer". The method mainly includes the steps of establishing a system reference, adjusting the beam splitter prism, adjusting the field widening prism and adjusting the grating. However, this technology only controls the accuracy of individual components of the interferometer, and the overall adjustment error is relatively large. Using traditional adjustment methods will have a great impact on the quality of the interference pattern. Summary of the invention

[0006] In order to solve the problem of relatively large overall adjustment error of the existing Doppler asymmetric spatial heterodyne interferometer, a Doppler asymmetric spatial heterodyne interferometer adjustment method is proposed. The method has a simple structure and is easy to implement, and can be used for precise adjustment of the Doppler asymmetric spatial heterodyne interferometer.

[0007] The technical solution of the present invention is:

[0008] A method for assembling and adjusting a Doppler asymmetric spatial heterodyne interferometer comprises the following steps:

[0009] Step 1, establish the installation benchmark;

[0010] Place theodolite 1 and theodolite 2 on a horizontal platform, adjust the two theodolites to be level and establish a reference. Use the light emitted by the self-collimation parallel light tube of theodolite 1 to establish a horizontal reference. The state shall not be changed after the reference is established.

[0011] Step 2, install and adjust the front lens;

[0012] Place the first and second lens barrels on the azimuth and elevation adjustment platform, stick the reference reflector 1 to the light inlet flange of the first lens barrel, make the collimator emit light, adjust the azimuth and elevation platform, make the light returned by the reference reflector enter the center of the field of view of the self-collimating collimator, and establish the reference state;

[0013] Adjust lens group 1 and lens barrel 1, lens group 2, lens group 3 and lens barrel 2 respectively, and use a centering instrument to detect the position of the lens spherical center image for correction;

[0014] Using the reference established by the self-collimating parallel light tube and the lens barrel, install the folding mirror one on the lens barrel, and adjust the angle of the folding mirror one so that the light emitted by the parallel light tube converges to the center of the star point plate through the folding mirror one.

[0015] Using the reference established by the self-collimating parallel light tube and the second lens barrel, install the second folding mirror on the second lens barrel, and adjust the angle of the second folding mirror so that the light emitted by the parallel light tube converges to the center of the star point plate through the second folding mirror;

[0016] Fix the lens barrel 1 and the lens barrel 2 through the flange to realize the integrated assembly and calibration of the front lens;

[0017] Step 3, install and adjust the rear lens;

[0018] Adjust lens group 4 and lens barrel 3, lens group 5, lens group 6 and lens barrel 4 respectively, use a centering instrument to detect the position of the lens spherical center image and make corrections, fix lens barrel 3 and lens barrel 4 through flanges to keep the optical axis concentric;

[0019] Place the lens barrel 3 and the lens barrel 4 on the azimuth and elevation adjustment table, place the theodolite 1 in front of the mounting flange of the lens barrel 3, place the theodolite 2 in front of the mounting flange of the lens barrel 4, stick the reference reflector 1 and the reference reflector 2 on the mounting flange surfaces of the lens barrel 3 and the lens barrel 4, use the theodolite 1 to align the reference reflector 1, adjust the theodolite 1 so that the optical axis is perpendicular to the mounting flange of the lens barrel 3, use the theodolite 2 to align the reference reflector 2, adjust the theodolite 2 so that the optical axis is perpendicular to the mounting flange of the lens barrel 4, and establish the reference state;

[0020] Using the datum established by the theodolite and the third and fourth lens tubes, install the folding mirror three, adjust the angle of the folding mirror, make the crosshairs of the target emitted by the theodolite one image in the field of view of the theodolite two, and move to the center of the field of view;

[0021] Step 4, assemble the overall assembly;

[0022] Place the load mounting plate on the azimuth-pitch adjustment table, stick a reference reflector 1 on the reference surface of the load mounting plate, make the collimator emit light, adjust the azimuth-pitch table, make the light returned by the reference reflector enter the center of the field of view of the self-collimating collimator, and establish the reference state;

[0023] Using the reference established by the load mounting plate and the self-collimating collimator, install the folding mirror assembly to the load mounting plate, adjust the angle of the folding mirror assembly, and make the light emitted by the collimator reflect back to the center of the field of view of the self-collimating collimator through the front lens filter;

[0024] Install the collimator and the collimator lens reflector on the load mounting plate, install the camera on the load mounting plate, make the collimator emit light, and image it on the camera through the front lens, interference module, and rear lens. Adjust the collimator lens reflector to move the imaging light spot to the center of the camera field of view, and adjust the camera defocus to make the imaging light spot the clearest image in the field of view.

[0025] After fixing all components, the installation and adjustment of the Doppler asymmetric spatial heterodyne interferometer is completed.

[0026] In step 2, adjust the front lens, use a centering instrument to check the lens assembly, and then apply glue to fix the lens assembly.

[0027] In step 2, the front lens is adjusted, and the star point plate is matched and fixed with the exit port of the lens barrel, and the optical axes of the two are concentric.

[0028] During the overall assembly and adjustment in step 4, the front lens, rear lens, and collimator lens can be assembled and adjusted in parallel, and the remaining components can be assembled after the assembly and adjustment are completed.

[0029] The beneficial effects of the present invention are as follows: the present invention adopts a system integration assembly and adjustment method to improve the overall assembly and adjustment accuracy, wherein the front lens, the rear lens, and the collimating lens can be assembled and calibrated in parallel to improve the assembly and adjustment efficiency. After completion, the whole machine is assembled and calibrated with the remaining parts to reduce the impact of installation errors and thereby obtain high-quality interference fringes. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the Doppler asymmetric spatial heterodyne interferometer after installation and adjustment;

[0031] Among them, 1-folding mirror assembly; 2-beam splitter prism; 3-collimating lens reflector; 4-filter; 5-collimating mirror; 6-front lens; 7-load mounting plate; 8-interference module; 9-rear lens; 10-imaging camera.

[0032] Figure 2 It is the front lens of Doppler asymmetric spatial heterodyne interferometer;

[0033] Among them, 6-1-lens group 1; 6-2-lens barrel 1; 6-3-folding mirror 1; 6-4-lens group 2; 6-5-folding mirror 2; 6-6-lens group 3; 6-7-lens barrel 2;

[0034] Figure 3 It is the rear lens of Doppler asymmetric spatial heterodyne interferometer;

[0035] Among them, 9-1-lens group four; 9-2-lens barrel three; 9-3-lens group five; 9-4-lens barrel four; 9-5-folding mirror three; 9-6-lens group six.

[0036] Figure 4 The figure is a flow chart of the installation and adjustment method of the Doppler asymmetric spatial heterodyne interferometer. DETAILED DESCRIPTION

[0037] The present invention will be further described and illustrated below in conjunction with the accompanying drawings.

[0038] like Figure 1 As shown, a Doppler asymmetric spatial heterodyne interferometer system includes a folding mirror assembly 1, a beam splitter prism 2, a collimating lens reflector 3, a filter 4, a collimating lens 5, a front lens 6, a load mounting plate 7, an interference module 8, a rear lens 9, and an imaging camera 10. The components are integrated with the load mounting plate 7 through flanges; signal light enters the system from the incident port of the folding mirror assembly 1, and is emitted after being folded 90° by the folding mirror assembly 1. The emitted light enters the beam splitter prism 2 and is then filtered by the filter 4. The filtered light The rear signal light is collimated and folded by the front lens 6, and cross-reflected on the interference module 8, and finally the interference signal is collected on the imaging camera 10 through the rear lens 9; the calibration light enters the system from the incident port of the collimator 5, and enters the beam splitter 2 after the light path is folded 90° by the collimator lens reflector 3. The split calibration light is filtered by the filter 4 and then enters the front lens 6, and is collimated and folded by the front lens 6, and cross-reflected on the interference module 8, and finally the interference signal is collected on the imaging camera 10 through the rear lens 9.

[0039] like Figure 2As shown, the front lens mainly includes lens group 1 6-1, lens barrel 1 6-2, folding mirror 1 6-3, lens group 2 6-4, folding mirror 2 6-5, lens group 3 6-6, and lens barrel 2 6-7, wherein lens group 1 6-1 is coaxially arranged with the light entrance port of lens barrel 1 6-2, lens group 2 6-4 is coaxially arranged with the light entrance port of lens barrel 2 6-7, lens group 3 6-6 is coaxially arranged with the light exit port of lens barrel 2 6-7, and lens barrel 1 6-2 and lens barrel 2 6-7 are integrated into one through a flange.

[0040] like Figure 3 As shown, the rear lens mainly includes lens group four 9-1, lens barrel three 9-2, lens group five 9-3, lens barrel four 9-4, folding lens three 9-5, and lens group six 9-6, wherein lens group four 9-1 is coaxially arranged with lens barrel three 9-2, lens group five 9-3 is coaxially arranged with the light entrance of lens barrel four 9-4, lens group six 9-6 is coaxially arranged with the light exit of lens barrel four 9-4, and lens barrel three 9-2 and lens barrel four 9-4 are integrated into one through a flange.

[0041] like Figure 4 As shown, a method for assembling and adjusting a Doppler asymmetric spatial heterodyne interferometer comprises the following steps:

[0042] Step 1, establish the installation benchmark;

[0043] Place theodolite 1 and theodolite 2 on a horizontal platform, adjust the levels of the two theodolites and establish a reference, place the autocollimation collimator in front of theodolite 1, use theodolite 1 to calibrate the output light of the autocollimation collimator so that it coincides with the center of the crosshairs of the theodolite, and establish the first reference state;

[0044] Step 2, install and adjust the front lens;

[0045] The lens group 1 6-1 and the lens barrel 1 6-2, the lens group 2 6-4 and the lens group 3 6-6 and the lens barrel 2 6-7 are respectively adjusted. First, the lens group 1 6-1 is placed in the lens barrel 1 6-2, and the position of the lens spherical center image is detected by a centering instrument for correction. After the requirements are met, the lens group 1 6-1 is pressed and fixed. Then, the lens group 2 6-4 and the lens group 3 6-6 are placed in the lens barrel 2 6-7, and the position of the lens spherical center image is detected by a centering instrument for correction. After the requirements are met, the lens group 2 6-4 and the lens group 3 6-6 are pressed and fixed.

[0046] Place the lens barrel 1 6-2 and the lens barrel 2 6-7 on the azimuth and elevation adjustment platforms respectively, stick the reference reflector 1 on the reference surface of the entrance of the lens barrel 1 6-2, make the collimator emit light, adjust the azimuth and elevation platforms, make the light returned by the reference reflector enter the center of the field of view of the self-collimating collimator, and establish the second reference state;

[0047] Using the second reference state, install the folding mirror 1 6-3 on the lens barrel 1 6-2, install the star point plate on the flange of the light outlet of the lens barrel 1 6-2, adjust the angle of the folding mirror 1 6-3, so that the light emitted by the collimator converges to the center of the star point plate through the folding mirror 1 6-3; install the folding mirror 2 6-5 on the lens barrel 2 6-7, install the star point plate on the flange of the light outlet of the lens barrel 2 6-7, adjust the angle of the folding mirror 2 6-5, so that the light emitted by the collimator converges to the center of the star point plate through the folding mirror 2 6-5; after the installation is completed, glue the folding mirror 1 6-3 and the folding mirror 2 6-5 to fix them;

[0048] Fix the lens barrel 1 6-2 and the lens barrel 2 6-7 through the flange to keep the optical axis concentric, so as to realize the integrated assembly and calibration of the front lens;

[0049] Step 3, install and adjust the rear lens;

[0050] The lens group 4 9-1 and the lens barrel 3 9-2, the lens group 5 9-3 and the lens group 6 9-6 and the lens barrel 4 9-4 are respectively adjusted. First, the lens group 4 9-1 is placed in the lens barrel 3 9-2, and the position of the lens spherical center image is detected by a centering instrument for correction. After the requirements are met, the lens group 4 9-1 is pressed and fixed. Then, the lens group 5 9-3 and the lens group 6 9-6 are placed in the lens barrel 4 9-4, and the position of the lens spherical center image is detected by a centering instrument for correction. After the requirements are met, the lens group 5 9-3 and the lens group 6 9-6 are pressed and fixed.

[0051] Fix the lens barrel 3 9-2 and the lens barrel 4 9-4 through the flange to keep the optical axis concentric, so as to realize the integrated assembly and calibration of the rear lens;

[0052] Place the lens barrel three 9-2 and lens barrel four 9-4 assembly on the azimuth and elevation adjustment platform, place theodolite one in front of the mounting flange of lens barrel three 9-2, place theodolite two in front of the mounting flange of lens barrel four 9-4, stick the reference reflector one on the surface of the mounting flange of lens barrel three 9-2, stick the reference reflector two on the surface of the mounting flange of lens barrel four 9-4, use theodolite one to align the reference reflector one, adjust theodolite one so that the optical axis is perpendicular to the mounting flange of lens barrel three 9-2, use theodolite two to align the reference reflector two, adjust theodolite two so that the optical axis is perpendicular to the mounting flange of lens barrel four 9-4, and establish the third reference state;

[0053] Using the established third reference state, install the folding mirror three 9-5 on the lens barrel four 9-4, adjust the angle of the folding mirror three 9-5, make the crosshairs of the target emitted by theodolite one image in the field of view of theodolite two, and move it to the center of the field of view. After the installation is completed, glue the folding mirror three 9-5 to fix it.

[0054] Step 4, assemble the overall assembly;

[0055] The front lens 6 , the interference module 8 , and the rear lens 9 are mounted on the load mounting plate 7 via flanges, and the filter 4 is mounted on the light entrance flange of the front lens 6 .

[0056] Place the load mounting plate 7 on the azimuth and pitch adjustment platform, paste the reference reflector 1 on the reference surface of the load mounting plate 7, make the collimator emit light, adjust the azimuth and pitch platform, make the light returned by the reference reflector 1 enter the center of the field of view of the self-collimating collimator, and establish the fourth reference state.

[0057] Using the established fourth reference state, install the folding mirror assembly 1 onto the load mounting plate 7, adjust the angle of the folding mirror assembly 1, and let the light emitted by the collimator be reflected back to the center of the field of view of the self-collimating collimator through the front lens filter 4. After the installation is completed, glue the folding mirror assembly 1 to fix it.

[0058] Install the collimator 5, collimator lens reflector 3, dichroic prism 2, and imaging camera 10 in the slot of the load mounting plate 7, adjust the collimator lens reflector 3 to move the imaging light spot to the center of the camera field of view, and adjust the camera defocus to make the imaging light spot the clearest image in the field of view.

[0059] After fixing all components, the installation and adjustment of the Doppler asymmetric spatial heterodyne interferometer is completed.

Claims

1. A method for assembling and adjusting a Doppler asymmetric spatial heterodyne interferometer, characterized in that: It includes the following steps: Step 1, establish the installation benchmark; Place theodolite 1 and theodolite 2 on a horizontal platform, adjust the two theodolites to be level and establish a reference. Use the light emitted by the self-collimation parallel light tube of theodolite 1 to establish a horizontal reference. The state shall not be changed after the reference is established. Step 2, install and adjust the front lens; Place the first and second lens barrels on the azimuth and elevation adjustment platform, stick the reference reflector 1 to the light inlet flange of the first lens barrel, make the collimator emit light, adjust the azimuth and elevation platform, make the light returned by the reference reflector enter the center of the field of view of the self-collimating collimator, and establish the reference state; Adjust lens group 1 and lens barrel 1, lens group 2, lens group 3 and lens barrel 2 respectively, and use a centering instrument to detect the position of the lens spherical center image for correction; Using the reference established by the self-collimating parallel light tube and the lens barrel, install the folding mirror one on the lens barrel, and adjust the angle of the folding mirror one so that the light emitted by the parallel light tube converges to the center of the star point plate through the folding mirror one. Using the reference established by the self-collimating parallel light tube and the second lens barrel, install the second folding mirror on the second lens barrel, and adjust the angle of the second folding mirror so that the light emitted by the parallel light tube converges to the center of the star point plate through the second folding mirror; Fix the lens barrel 1 and the lens barrel 2 through the flange to realize the integrated assembly and calibration of the front lens; Step 3, install and adjust the rear lens; Adjust lens group 4 and lens barrel 3, lens group 5, lens group 6 and lens barrel 4 respectively, use a centering instrument to detect the position of the lens spherical center image and make corrections, fix lens barrel 3 and lens barrel 4 through flanges to keep the optical axis concentric; Place the lens barrel 3 and the lens barrel 4 on the azimuth and elevation adjustment table, place the theodolite 1 in front of the mounting flange of the lens barrel 3, place the theodolite 2 in front of the mounting flange of the lens barrel 4, stick the reference reflector 1 and the reference reflector 2 on the mounting flange surfaces of the lens barrel 3 and the lens barrel 4, use the theodolite 1 to align the reference reflector 1, adjust the theodolite 1 so that the optical axis is perpendicular to the mounting flange of the lens barrel 3, use the theodolite 2 to align the reference reflector 2, adjust the theodolite 2 so that the optical axis is perpendicular to the mounting flange of the lens barrel 4, and establish the reference state; Using the datum established by the theodolite and the third and fourth lens tubes, install the folding mirror three, adjust the angle of the folding mirror, make the crosshairs of the target emitted by the theodolite one image in the field of view of the theodolite two, and move to the center of the field of view; Step 4, assemble the overall assembly; Place the load mounting plate on the azimuth-pitch adjustment table, stick a reference reflector 1 on the reference surface of the load mounting plate, make the collimator emit light, adjust the azimuth-pitch table, make the light returned by the reference reflector enter the center of the field of view of the self-collimating collimator, and establish the reference state; Using the reference established by the load mounting plate and the self-collimating collimator, install the folding mirror assembly to the load mounting plate, adjust the angle of the folding mirror assembly, and make the light emitted by the collimator reflect back to the center of the field of view of the self-collimating collimator through the front lens filter; Install the collimator and the collimator lens reflector on the load mounting plate, install the camera on the load mounting plate, make the collimator emit light, and image it on the camera through the front lens, interference module, and rear lens. Adjust the collimator lens reflector to move the imaging light spot to the center of the camera field of view, and adjust the camera defocus to make the imaging light spot the clearest image in the field of view. After fixing all components, the installation and adjustment of the Doppler asymmetric spatial heterodyne interferometer is completed.

2. The method for assembling and adjusting a Doppler asymmetric spatial heterodyne interferometer according to claim 1, characterized in that: In the step 2, the front lens is adjusted, and after the lens assembly is tested for conformity by a centering instrument, the lens assembly is fixed by applying glue.

3. The method for assembling and adjusting a Doppler asymmetric spatial heterodyne interferometer according to claim 1, characterized in that: In step 2, the front lens is adjusted, and the star point plate is matched and fixed with the exit port of the lens barrel, and the optical axes of the two are concentric.

4. The method for assembling and adjusting a Doppler asymmetric spatial heterodyne interferometer according to claim 1, characterized in that: During the overall assembly and adjustment in step 4, the front lens, the rear lens, and the collimating lens can be assembled and adjusted in parallel, and the remaining components can be assembled after the assembly and adjustment are completed.

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