CN110793755B - Knife-edge device and method for measuring focal length in assembly and adjustment of reflecting telephoto telescope - Google Patents
Knife-edge device and method for measuring focal length in assembly and adjustment of reflecting telephoto telescope Download PDFInfo
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- CN110793755B CN110793755B CN201911093495.6A CN201911093495A CN110793755B CN 110793755 B CN110793755 B CN 110793755B CN 201911093495 A CN201911093495 A CN 201911093495A CN 110793755 B CN110793755 B CN 110793755B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
- G01M11/02—Testing optical properties
- G01M11/0242—Testing optical properties by measuring geometrical properties or aberrations
- G01M11/0271—Testing optical properties by measuring geometrical properties or aberrations by using interferometric methods
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
- G01M11/02—Testing optical properties
- G01M11/0207—Details of measuring devices
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Abstract
The invention discloses a knife edge device for measuring focal length in the installation and adjustment of a reflection tele telescope and a measuring method. In the process of installing and adjusting the large-caliber telescope, a knife edge device with a readable high-precision five-dimensional adjusting frame is adopted, and a laser interferometer and a photoelectric autocollimator which are used in the process of installing and adjusting are additionally arranged, so that the focal length of a telescope system is tested with high precision in the process of installing and adjusting the large-caliber reflective long-focus telescope, the problem that the focal length of a primary mirror cannot be accurately controlled in the process of installing and adjusting the traditional large-caliber reflective long-focus telescope is solved, and the installing and adjusting precision and the optical correction efficiency are greatly improved.
Description
Technical Field
The invention belongs to the field of optical testing and optical adjustment, relates to a knife edge device and a method for measuring focal length in the adjustment of a reflection tele telescope, and also relates to a method for measuring focal length of a large-caliber reflection tele telescope system in the adjustment process by using the knife edge device.
Background
In order to realize higher resolution, the caliber of the telescope system is larger and larger, the focal length of the system is longer, and the focal length control of the large-caliber reflective telescope optical system is required to be more and more accurate. The focal length of the large-caliber reflection type long-focus telescope system is accurately tested and controlled in the optical processing and optical adjustment processes.
In the traditional optical adjustment process, two main focal length measurement methods for a large-caliber reflective tele telescope system are adopted, namely, in the first method, glass Luo Ban (a parallel flat plate with a fixed width line pair) is placed on the focal plane of the telescope system, then a theodolite is utilized to test the corresponding angle of the fixed width line pair before a primary mirror of the telescope system, and then the focal length of the system can be calculated. In the method, the surface of the glass plate with a certain thickness, where the actually tested line pair with a fixed width is positioned, is not positioned on the focal plane, and in addition, in the process of testing the angle corresponding to the fixed line width by using the theodolite, the focal length test error of the tele telescope is larger due to the human error of line pressing interpretation. In the second method, a detector is required to be placed on the focal plane of the telescope, then the telescope system and the detector are used as a whole, the long-focus collimator is aligned, a point light source on the focal plane of the collimator forms an image point on the detector, the telescope system is rotated for a fixed angle, and the distance between two image points on the detector is tested, so that the focal length of the system can be calculated. In the method, the detector is required to be installed on the focal plane of the telescope system, the installation precision of the process influences the test precision, in addition, the telescope system is required to be tested by special show to change a test light path, the detector is required to be installed again in each test, and the optical adjustment efficiency of the large-caliber telescope system is very low.
Therefore, how to test the focal length of the large-caliber reflective tele telescope system in real time with high precision and high efficiency in the optical adjustment process, and guide adjustment is a problem to be solved in the field of optical adjustment.
Disclosure of Invention
The invention aims to provide a knife edge device for testing the focal length of a system in the optical adjustment process of a large-caliber reflection type long-focus telescope, wherein the lower part of the device is a readable high-precision five-dimensional adjusting frame 3 and can be read. The upper part of the device is a cubic prism 2 with a cross wire and a knife edge 1 which are arranged on a high-precision five-dimensional adjusting frame 3. The laser interferometer 4 emits ideal spherical waves from point A, the ideal spherical waves are formed into parallel light through a telescope system consisting of a primary mirror (8) and a secondary mirror 9, the parallel light is incident into a large-caliber standard plane mirror 10 and is reflected back to the telescope system to be converged at point B, when the optical axis of the telescope system is coincident with the normal line of the large-caliber standard plane mirror 10, point A, B is coincident, when the optical axis of the telescope system is at a certain angle with the normal line of the large-caliber standard plane mirror 10, point A, B is not coincident, and the focal length of the telescope system can be calculated according to the distance and the angle of the point A, B.
Another object of the present invention is to provide a method for measuring a focal length of a large-caliber reflective tele telescope optical system by using the knife edge device, which specifically includes the following steps:
Placing a knife edge 1, a cubic prism 2 with a cross reticle, a high-precision five-dimensional adjusting frame 3 with a reading, a laser interferometer 4, a large five-dimensional adjusting frame 5, a plane reflector 6, a large-caliber reflecting type tele telescope system consisting of a primary mirror 8 and a secondary mirror 9 on the same large turntable, and adjusting a large-caliber standard plane mirror 10 and the laser interferometer 4 to make the normal line of the large-caliber standard plane mirror 10 and the optical axis of the laser interferometer 4 collinear with the optical axis of the large-caliber reflecting type tele telescope system consisting of the primary mirror 8 and the secondary mirror 9, and testing zero-view wave aberration of the large-caliber telescope system consisting of the primary mirror 8 and the secondary mirror 9 by using the laser interferometer 4, wherein the focus-off value is zero as shown in a figure 3 (1);
step two, replacing a spherical lens of the laser interferometer 4 with a planar lens, and adjusting the rotation and pitching dimensions of the readable high-precision five-dimensional adjusting frame 3 to enable the normal line of the cubic prism 2 with the cross score line to be collinear with the optical axis of the laser interferometer 4, as shown in fig. 3 (2);
And thirdly, replacing a plane lens of the laser interferometer 4 with a spherical lens, and adjusting the translation dimension of the high-precision five-dimensional adjusting frame 3 which can be read and is perpendicular to the optical axis to enable the knife edge to be exactly cut on a focus A of the lens of the interferometer, and judging by checking interference fringes on the interferometer. Recording the reading H 1 of the translation dimension of the high-precision five-dimensional adjusting frame 3 perpendicular to the optical axis, as shown in fig. 3 (3);
Aligning the photoelectric auto-collimator 7 with a plane reflector 6 on the large turntable, recording the angle theta 1 at the moment, rotating the large turntable, and recording the angle theta 2 of the photoelectric auto-collimator 7 at the moment, as shown in fig. 3 (4);
Step five, adjusting the translation dimension of the high-precision five-dimensional adjusting frame 3 which can be read and is perpendicular to the optical axis, so that the edge of the laser exactly passes through a large-caliber telescope system consisting of a primary mirror 8 and a secondary mirror 9, is reflected by a large-caliber standard plane mirror 10, and is overlapped with the point B converged by the large-caliber telescope system again, and recording the reading H 2 of the translation dimension of the high-precision five-dimensional adjusting frame 3 which is perpendicular to the optical axis at the moment, as shown in the accompanying figures 3 (5) and (6);
step six, the focal length of the large-caliber telescope system can be calculated as follows:
The invention has the characteristics and beneficial effects that (1) the knife edge device for measuring the focal length is simple and small and is easy to construct, (2) high-precision test equipment can be adopted for testing two parameters for calculating the focal length, the focal length precision of the large-caliber reflective teletelescope system calculated by test is high, (3) the knife edge device and the measuring method can be used for testing in the optical adjustment process of the large-caliber reflective teletelescope system without dismantling an optical adjustment light path, without transferring, and the test efficiency is improved at any time, and (4) equipment test data are adopted in the test process, so that the artificial reading error is eliminated, and the test repetition precision is greatly improved.
Drawings
FIG. 1 is a schematic view of a knife edge device assembly and test light path of the present invention;
FIG. 2 is a schematic diagram of a self-optical calibration step of a knife edge device for testing the focal length of a large-caliber reflective tele telescope, wherein FIG. 1 is a schematic diagram of a first self-optical calibration step of the knife edge device, FIG. 2 is a schematic diagram of a second self-optical calibration step of the knife edge device, and FIG. 3 is a schematic diagram of a third self-optical calibration step of the knife edge device;
Fig. 3 is a schematic diagram of a method for testing a focal length of a large-caliber reflective tele telescope according to the present invention, wherein fig. 1 is a schematic diagram of a first step of measuring a focal length, fig. 2 is a schematic diagram of a second step of measuring a focal length, fig. 3 is a schematic diagram of a third step of measuring a focal length, fig. 4 is a schematic diagram of a fourth step of measuring a focal length, fig. 5 is a schematic diagram of a fifth step of measuring a focal length, and fig. 6 is a schematic diagram of a sixth step of measuring a focal length.
Detailed Description
Examples of the implementation of the method of the present patent are described in detail below with reference to the accompanying drawings.
The main components used in the present invention are described:
The cube prism 2 is custom-manufactured, the side length is 35mm, the angle difference and the tower difference of 90 degrees are better than 3 seconds, each surface type RMS is better than 1/15 wavelength @633nm, six aluminum-plated reflecting films are formed on one surface, and cross lines are engraved on one surface of each film, and the material K9 is used.
The photoelectric autocollimator 8 is a TriAngle company model TA500-57 photoelectric autocollimator, the aperture of light transmission is 50mm, the angle of view is 1300X950 seconds, the resolution is 0.02 seconds, and the repetition accuracy is +/-0.05 seconds.
The high-precision five-dimensional adjusting frame 3 capable of reading is used for adjusting the direction of a knife edge and comprises horizontal dimension adjustment, front-back dimension adjustment, high-low dimension adjustment, pitching dimension adjustment and rotating dimension adjustment, wherein the horizontal dimension adjustment precision is better than 5um, and the knife edge can be read.
The invention relates to a knife edge device for testing the focal length of a large-caliber reflective tele telescope, which comprises the following specific steps:
The first step is to install the cube prism 2 on the readable high-precision five-dimensional adjusting frame 3, which is perpendicular to the optical axis direction of the interferometer, wherein the surface of the cube prism 2 carved with the cross line faces the adjusting direction of the horizontal dimension. The photoelectric inner focusing 11 is aligned to the cubic prism 2, and the photoelectric inner focusing 11 is adjusted, so that the light emitted by the photoelectric inner focusing 11 passes through the cross line of the original path of the surface of the cubic prism 2 and is positioned at the center of the detector of the photoelectric inner focusing 11, as shown in fig. 2 (1).
And secondly, adjusting the focal length of the photoelectric internal focusing 11 to enable the internal focusing to be imaged and the surface of the cubic prism 2, and adjusting the translation of the photoelectric internal focusing 11 to enable a cross line on the surface of the cubic prism 2 to be positioned at the center of a detector of the photoelectric internal focusing 11, as shown in fig. 2 (2).
And thirdly, adjusting the horizontal dimension of the high-precision five-dimensional adjusting frame 3 which is capable of reading and is perpendicular to the optical axis direction of the interferometer to the other end, and adjusting the focal length of the photoelectric internal focusing 11 to enable the cross score line on the surface of the cube prism 2 to be clearly imaged on the detector of the photoelectric internal focusing 11, and checking whether the cross score line imaging on the surface of the cube prism 2 deviates from the center of the detector. If the deviation exists, the angle of the cubic prism 2 is adjusted, then the step 1) is carried out, then the step 2) is carried out, and the step 3) is carried out until the deviation exists between the image formed by the cross score line on the surface of the cubic prism 2 in the step 3) and the center of the detector, as shown in the figure 2 (3), the knife edge device for testing the focal length of the large-caliber reflection type long-focus telescope system is assembled and adjusted.
Claims (6)
1. The utility model provides a measure knife edge device of focus in reflection tele telescope dress is transferred, includes knife edge (1), takes cubic prism (2) of cross dividing, five dimension adjustment frame (3) of high accuracy of reading, laser interferometer (4), large-scale five dimension adjustment frame (5), plane mirror (6), photoelectric auto-collimator (7), its characterized in that:
The lower part of the knife edge device is a readable high-precision five-dimensional adjusting frame (3), the upper part of the knife edge device is a cube prism (2) with a cross wire and a knife edge (1) which are arranged on the high-precision five-dimensional adjusting frame (3), an ideal spherical wave is emitted by an A point through a laser interferometer (4), the ideal spherical wave is formed into parallel light through a telescope system consisting of a primary mirror (8) and a secondary mirror (9), the parallel light is incident into a large-caliber standard plane mirror (10) and is reflected back to the telescope system to be converged at a B point, when an optical axis of the telescope system is coincident with a normal of the large-caliber standard plane mirror (10), a A, B point is coincident, when the optical axis of the telescope system is at a certain angle with the normal of the large-caliber standard plane mirror (10), a A, B point is not coincident, and the focal length of the telescope system can be calculated according to the distance and the angle of the A, B point.
2. The knife edge device for measuring focal length in the installation and adjustment of the reflecting tele telescope according to claim 1, wherein the cubic prism (2) with the cross score line is made of quartz material, the vertical angle difference and the tower difference are both better than 3 seconds, six surface RMS are better than 1/15 wavelength @633nm, the reflectivity of six surface aluminized reflecting films is greater than 90%, and one surface is carved with the cross score line.
3. The knife edge device for measuring focal length in the installation and adjustment of the reflecting tele telescope according to claim 1, wherein the readable high-precision five-dimensional adjusting frame (3) is used for adjusting the direction of a knife edge and comprises horizontal dimension adjustment, front-back dimension adjustment, height dimension adjustment, pitching dimension adjustment and rotating dimension adjustment, wherein the horizontal dimension adjustment precision is better than 5um.
4. The knife edge device for measuring focal length in the installation and adjustment of the reflection tele telescope according to claim 1, wherein the large five-dimensional adjusting frame (5) is used for adjusting the azimuth of the interferometer and comprises horizontal dimension adjustment, front-back dimension adjustment, height dimension adjustment, pitching dimension adjustment and rotating dimension adjustment.
5. The knife edge device for measuring focal length in the adjustment of the reflecting tele telescope according to claim 1, characterized in that the angular resolution of the photoelectric auto-collimator (7) is 0.02 seconds, the repetition accuracy is ± 0.05 seconds.
6. A focal length measuring method based on the knife edge device for measuring focal length in the installation and adjustment of the reflecting tele telescope as claimed in claim 1, characterized by comprising the following steps:
Placing a knife edge (1), a cubic prism (2) with a cross line, a high-precision five-dimensional adjusting frame (3) with a reading, a laser interferometer (4), a large-scale five-dimensional adjusting frame (5), a plane reflecting mirror (6) and a large-caliber reflecting type long-focus telescope system consisting of a primary mirror (8) and a secondary mirror (9) on the same large turntable, adjusting a large-caliber standard plane mirror (10) and the laser interferometer (4) to enable the normal line of the large-caliber standard plane mirror (10) and the optical axis of the laser interferometer (4) to be collinear with the optical axis of the large-caliber reflecting type long-focus telescope system consisting of the primary mirror (8) and the secondary mirror (9), and testing zero-view wave aberration of the large-caliber telescope system consisting of the primary mirror (8) and the secondary mirror (9) by using the laser interferometer (4) to enable the focus-off value to be zero;
Step two, replacing a spherical lens of the laser interferometer (4) by using a plane lens, and adjusting the rotation and pitching dimensions of a readable high-precision five-dimensional adjusting frame (3) so that the normal line of the cubic prism (2) with the cross reticle is collinear with the optical axis of the laser interferometer (4);
Step three, replacing a plane lens of the laser interferometer (4) by a spherical lens, and adjusting the translation dimension of the high-precision five-dimensional adjusting frame (3) which can be read out and is perpendicular to the optical axis, so that a knife edge is exactly cut on a focus A of the lens of the interferometer, and judging by checking interference fringes on the interferometer;
Aligning the photoelectric auto-collimator (7) to a plane reflecting mirror (6) on a large turntable, recording the angle theta 1 at the moment, rotating the large turntable, and recording the angle theta 2 of the photoelectric auto-collimator (7) at the moment;
regulating the translation dimension of the high-precision five-dimensional adjusting frame (3) which can be read and is perpendicular to the optical axis, enabling the knife edge to be exactly perpendicular to the optical axis, enabling laser emitted by the laser interferometer (4) to pass through a large-caliber telescope system consisting of a primary mirror (8) and a secondary mirror (9), reflecting the laser by a large-caliber standard plane mirror (10), and then overlapping the B point converged by the large-caliber telescope system again, and recording the reading H 2 of the translation dimension of the high-precision five-dimensional adjusting frame (3) which is perpendicular to the optical axis at the moment;
step six, the focal length of the large-caliber telescope system can be calculated as follows:
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| CN113126312B (en) * | 2021-03-05 | 2022-02-11 | 中国科学院西安光学精密机械研究所 | Method for assembling and adjusting large-size collimator focal plane assembly |
| CN113092076B (en) * | 2021-04-23 | 2022-10-14 | 航天科工微电子系统研究院有限公司 | Method and light path for detecting field focal length of large-diameter zoom reflection telescope |
| CN114252242B (en) * | 2021-11-23 | 2024-05-31 | 中国航空工业集团公司洛阳电光设备研究所 | Optical axis calibration tool and method for telescopic system and optical system comprising front telescopic system |
| CN114279687B (en) * | 2021-12-17 | 2023-01-03 | 中国科学院长春光学精密机械与物理研究所 | Measuring device and measuring method for relative deflection of primary mirror and secondary mirror |
| CN115979597B (en) * | 2023-02-13 | 2024-01-12 | 杭州简并激光科技有限公司 | Defect detection method for conical mirror of laser level meter |
| CN115981023B (en) * | 2023-02-17 | 2024-08-30 | 西安应用光学研究所 | Hyperboloid or ellipsoidal reflector optical axis precise calibration device and calibration method |
| CN117470499B (en) * | 2023-07-18 | 2024-05-28 | 长春国宇光学科技有限公司 | Method for adjusting optical element |
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| CN211696888U (en) * | 2019-11-11 | 2020-10-16 | 中国科学院上海技术物理研究所 | Knife edge device for measuring focal length in installation and adjustment of long-focus reflection telescope |
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| CN101140196B (en) * | 2007-09-11 | 2011-01-26 | 中国科学院上海光学精密机械研究所 | Lens focal length measuring device and measuring method thereof and optical quality evaluation method |
| CN103105283B (en) * | 2011-11-15 | 2015-03-11 | 中国科学院西安光学精密机械研究所 | Focal length measuring device of single-spectrum large-caliber long-focus lens |
| CN106066239A (en) * | 2016-05-25 | 2016-11-02 | 中国科学院长春光学精密机械与物理研究所 | Detection device and method is debug at large telescope scene based on guiding |
| RU2690723C1 (en) * | 2017-12-19 | 2019-06-05 | Российская Федерация, от имени которой выступает Министерство обороны Российской Федерации | Method and device for automatic adjustment of mirror telescopes |
| CN109029925B (en) * | 2018-06-12 | 2023-12-26 | 中国科学院上海技术物理研究所 | Cubic prism optical correction device for sighting and monitoring telescope optical axis |
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