Large-aperture spliced mirror curvature radius detection system based on photon lead

Abstract

The invention relates to the technical field of curvature radius detection, and discloses a large-aperture spliced mirror curvature radius detection system based on a photon lead, and the system comprises an integrated optical waveguide interference array which is used for being placed in the center of a system region and transmitting two beams of similar spherical waves to a detected mirror surface; the frequency carrier module is used for modulating interference fringes formed by the light beams reflected by the measured mirror surface so as to obtain the actual wavefront of the system; the signal processing module is used for performing Fourier transform on the modulated interference fringes to obtain the wavefront curvature of the system; the laser tracker is used for determining the positions of input and output light spots; and the curvature calculation module is used for obtaining the accurate curvature radius of the measured mirror surface. According to the invention, an integrated optical waveguide interference array is adopted to emit spherical waves, so that the assembly error of discrete optical elements is reduced, and the system stability is improved; the interference fringes are modulated through frequency carrier waves, and the Fourier transform algorithm is combined, so that the analysis precision of the wavefront curvature is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of curvature radius detection technology, and in particular to a curvature radius detection system for a large-aperture splicing mirror based on photon leads. Background Technology

[0002] In the field of optical engineering, the wavefront curvature of a mirror is a core indicator for evaluating its optical performance, directly affecting the imaging quality, beam focusing accuracy, and energy transmission efficiency of an optical system. Whether it's the primary mirror of an astronomical telescope, the reflector of a semiconductor lithography device, or the focusing mirror of a laser processing system, the accuracy of its curvature parameter measurement must reach the micrometer or even nanometer level. However, the stability and accuracy of existing wavefront curvature measurement technologies still need improvement. The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0003] The main objective of this invention is to provide a large-aperture splicing mirror curvature radius detection system based on photon leads, aiming to solve the technical problem of poor existing curvature radius detection performance.

[0004] To achieve the above objectives, the present invention provides a large-aperture spliced ​​mirror curvature radius detection system based on photonic leads, the large-aperture spliced ​​mirror curvature radius detection system based on photonic leads comprising: An integrated optical waveguide interferometer array is placed at the center of the system area to emit two similar spherical waves to the mirror under test. A frequency carrier module modulates the interference fringes formed by the reflected beams from the mirror under test to obtain the actual wavefront of the system. A signal processing module performs a Fourier transform on the modulated interference fringes to obtain the wavefront curvature of the system. A laser tracker determines the positions of the input and output light spots. A curvature calculation module combines the focal position determined by the laser tracker, the system defocusing amount, and the curvature of the interference fringes to obtain the precise radius of curvature of the mirror under test. For segmented mirrors under test, regional fitting is performed for each part.

[0005] In one embodiment, the system further includes an aperture coding module, which is used to change the direction of the projected light intensity based on the aperture coding method, fit the radius of curvature of the mirror surface under test in various directions, so as to ensure the rotational symmetry of the system and improve the application performance of the free-form surface under test mirror.

[0006] In one embodiment, the system further includes an interferometric system module, which can construct a new multimode, single-mode, or hybrid interferometric system. The hybrid interferometric system utilizes the strong light-collecting ability and high efficiency of multimode optical fiber, and the strong spatial filtering effect and reference construction of single-mode optical fiber, to perform interferometric synthesis of the two, so as to realize the metrological detection of the wavefront of the measured mirror and the high-throughput and high-efficiency detection of the system.

[0007] In one embodiment, the system further includes a detector end, which uses a multimode photonic lead to construct an optical circulator to achieve high-efficiency detection of the beam reflected from the test mirror at the input end.

[0008] In one embodiment, the aperture encoding module includes multiple encoding units, which can change the distribution weight of the projected light intensity in different directions by adjusting the encoding mode.

[0009] In one embodiment, the interference system module includes a multimode fiber unit, a single-mode fiber unit, and a beam combining unit, wherein the beam combining unit is used to interferometrically combine the beams output by the multimode fiber unit and the single-mode fiber unit.

[0010] In one embodiment, the optical circulator includes an input end, a detection end, and a reflection end, wherein the reflection end is used to receive the light beam reflected by the mirror under test and transmit it to the detection end.

[0011] In one embodiment, when the curvature calculation module performs segmented fitting on the segmented test mirror, it can independently calculate the curvature radius of the corresponding region based on the interference fringe characteristics of each segment.

[0012] This invention provides a large-aperture spliced ​​mirror curvature radius detection system based on photonic leads. The system includes an integrated optical waveguide interference array, placed at the center of the system region, emitting two similar spherical waves to the mirror under test; a frequency carrier module, used to modulate the interference fringes formed by the reflected beams from the mirror under test to obtain the actual wavefront of the system; a signal processing module, used to perform Fourier transform on the modulated interference fringes to obtain the wavefront curvature of the system; a laser tracker, used to determine the positions of the input and output light spots; and a curvature calculation module, used to combine the focal position determined by the laser tracker, the system defocusing amount, and the curvature of the interference fringes to obtain the accurate curvature radius of the mirror under test; for segmented mirrors under test, regional fitting is performed for each part. This invention utilizes an integrated optical waveguide interferometer array to emit spherical waves, reducing assembly errors of discrete optical components and improving system stability. By modulating interference fringes with a frequency carrier and combining it with a Fourier transform algorithm, the analytical accuracy of wavefront curvature is significantly improved. The laser tracker and curvature calculation module work together to achieve multi-parameter fusion analysis of focal position, defocus amount, and fringe curvature characteristics, making it particularly suitable for segmented detection of segmented mirrors. An optional aperture encoding module expands the detection capability for freeform mirrors, while the interferometer module and optical circulator design balance detection efficiency and reference accuracy. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of a large-aperture splicing mirror curvature radius detection system based on photonic leads in the hardware operating environment involved in the embodiments of the present invention.

[0014] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0015] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0016] This invention provides a large-aperture spliced ​​mirror curvature radius detection system based on photonic leads, referring to... Figure 1 , Figure 1This is a structural block diagram of the system of the present invention. The large-aperture spliced ​​mirror curvature radius detection system based on photonic leads includes: an integrated optical waveguide interference array, used to be placed at the center of the system region to emit two similar spherical waves to the mirror under test; a frequency carrier module, used to modulate the interference fringes formed by the reflected beams from the mirror under test to obtain the actual wavefront of the system; a signal processing module, used to perform Fourier transform on the modulated interference fringes to obtain the wavefront curvature of the system; a laser tracker, used to determine the positions of the input and output light spots; a curvature calculation module, used to combine the focal position determined by the laser tracker, the system defocusing amount, and the curvature of the interference fringes to obtain the accurate curvature radius of the mirror under test; for segmented mirrors under test, regional fitting is performed for each part.

[0017] The wavefront curvature measurement system disclosed in this invention includes an integrated optical waveguide interferometer array, a frequency carrier module, a signal processing module, a laser tracker, a curvature calculation module, and optional aperture encoding module, interferometric system module, and a detection end. The modules are connected via optical or electrical signal lines to form a complete detection system.

[0018] Example 1: Detection of a spherical mirror surface 1. Fix the integrated optical waveguide interferometer array at the center of the system area, and project the two beams of spherical waves emitted by it onto the spherical mirror under test at an incident angle of 30°; 2. The two beams of light reflected from the mirror under test form interference fringes. The frequency carrier module uses a 10MHz sine wave signal to modulate the fringes, generating a modulated signal carrying wavefront information. 3. The signal processing module performs a Fourier transform on the modulated signal, extracts the 0th and ±1st order spectral components, and calculates the preliminary wavefront curvature; 4. The laser tracker emits a tracking laser and records the incident position (x1, y1, z1) of the input light point on the surface under test and the reflection position (x2, y2, z2) of the output light point. 5. The curvature calculation module calls the preset algorithm and, combined with the focal position obtained by the laser tracker, the defocus amount of the 5μm system, and the fringe curvature parameters, calculates the radius of curvature of the spherical mirror under test to be 500.002mm, with a measurement error ≤ ±0.005mm.

[0019] Example 2: Inspection of segmented mirror surfaces When the mirror being tested is a 6-segment aspherical mirror: 1. An integrated optical waveguide interference array sequentially emits spherical waves to each segment of the mirror, and the frequency carrier module uses time-division multiplexing to modulate each interference fringe segment; 2. The signal processing module performs a Fourier transform independently on the fringe signal of each segment of the mirror to obtain the local wavefront curvature of each segment; 3. The laser tracker marks the input and output light point positions of each segment of the mirror surface to establish a segmented coordinate system; 4. The curvature calculation module performs regional fitting on each segment of the mirror surface, corrects edge errors by verifying the curvature continuity of adjacent segments, and finally outputs the curvature radius and splicing error of each segment.

[0020] Example 3: Inspection of a freeform surface mirror When the aperture encoding module is enabled: 1. The aperture encoding module changes the direction of light intensity projected onto the freeform surface of the measured mirror through a microlens array, forming a multi-directional encoded light field; 2. The interferometric system module switches to a hybrid interferometric mode, where the multimode fiber unit collects diffuse reflection light from the freeform surface, and the single-mode fiber unit provides reference light. The two are then interferometrically synthesized by the beam combiner unit. 3. The optical circulator at the detector end efficiently transmits the synthesized signal to the signal processing module, and after Fourier transform, the multi-directional wavefront curvature is obtained; 4. The curvature calculation module combines the three-dimensional positioning data of the laser tracker to fit the curvature radius of the free surface in the X, Y, and Z directions, realizing comprehensive detection of non-rotationally symmetric structures.

[0021] In one embodiment, the system further includes an aperture coding module, which is used to change the direction of the projected light intensity based on the aperture coding method, fit the radius of curvature of the mirror surface under test in various directions, so as to ensure the rotational symmetry of the system and improve the application performance of the free-form surface under test mirror.

[0022] In one embodiment, the system further includes an interferometric system module, which can construct a new multimode, single-mode, or hybrid interferometric system. The hybrid interferometric system utilizes the strong light-collecting ability and high efficiency of multimode optical fiber, and the strong spatial filtering effect and reference construction of single-mode optical fiber, to perform interferometric synthesis of the two, so as to realize the metrological detection of the wavefront of the measured mirror and the high-throughput and high-efficiency detection of the system.

[0023] In one embodiment, the system further includes a detector end, which uses a multimode photonic lead to construct an optical circulator to achieve high-efficiency detection of the beam reflected from the test mirror at the input end.

[0024] In one embodiment, the aperture encoding module of the system also includes multiple encoding units, which can change the distribution weight of the projected light intensity in different directions by adjusting the encoding mode.

[0025] In one embodiment, the interference system module includes a multimode fiber unit, a single-mode fiber unit, and a beam combining unit, wherein the beam combining unit is used to interferometrically combine the beams output by the multimode fiber unit and the single-mode fiber unit.

[0026] In one embodiment, the optical circulator includes an input end, a detection end, and a reflection end, wherein the reflection end is used to receive the light beam reflected by the mirror under test and transmit it to the detection end.

[0027] In one embodiment, when the curvature calculation module performs segmented fitting on the segmented test mirror, it can independently calculate the curvature radius of the corresponding region based on the interference fringe characteristics of each segment.

[0028] This invention provides a large-aperture spliced ​​mirror curvature radius detection system based on photonic leads. The system includes an integrated optical waveguide interference array, placed at the center of the system region, emitting two similar spherical waves to the mirror under test; a frequency carrier module, used to modulate the interference fringes formed by the reflected beams from the mirror under test to obtain the actual wavefront of the system; a signal processing module, used to perform Fourier transform on the modulated interference fringes to obtain the wavefront curvature of the system; a laser tracker, used to determine the positions of the input and output light spots; and a curvature calculation module, used to combine the focal position determined by the laser tracker, the system defocusing amount, and the curvature of the interference fringes to obtain the accurate curvature radius of the mirror under test; for segmented mirrors under test, regional fitting is performed for each part. This invention utilizes an integrated optical waveguide interferometer array to emit spherical waves, reducing assembly errors of discrete optical components and improving system stability. By modulating interference fringes with a frequency carrier and combining it with a Fourier transform algorithm, the analytical accuracy of wavefront curvature is significantly improved. The laser tracker and curvature calculation module work together to achieve multi-parameter fusion analysis of focal position, defocus amount, and fringe curvature characteristics, making it particularly suitable for segmented detection of segmented mirrors. An optional aperture encoding module expands the detection capability for freeform mirrors, while the interferometer module and optical circulator design balance detection efficiency and reference accuracy.

[0029] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A system for detecting the radius of curvature of a large-aperture spliced ​​mirror based on photonic leads, characterized in that, The large-aperture spliced ​​mirror curvature radius detection system based on photonic leads includes: An integrated optical waveguide interferometer array is placed at the center of the system area to emit two similar spherical waves to the mirror under test. A frequency carrier module modulates the interference fringes formed by the reflected beams from the mirror under test to obtain the actual wavefront of the system. A signal processing module performs a Fourier transform on the modulated interference fringes to obtain the wavefront curvature of the system. A laser tracker determines the positions of the input and output light spots. A curvature calculation module combines the focal position determined by the laser tracker, the system defocusing amount, and the curvature of the interference fringes to obtain the precise radius of curvature of the mirror under test. For segmented mirrors under test, regional fitting is performed for each part.

2. The large-aperture spliced ​​mirror curvature radius detection system based on photonic leads as described in claim 1, characterized in that, The system also includes an aperture coding module, which is used to change the direction of the projected light intensity based on the aperture coding method, fit the radius of curvature of the mirror surface under test in various directions, so as to ensure the rotational symmetry of the system and improve the application performance of the free-form surface under test mirror.

3. The large-aperture splicing mirror curvature radius detection system based on photonic leads as described in claim 1, characterized in that, The system also includes an interferometric system module, which can construct multimode, single-mode, or hybrid interferometric systems. The hybrid interferometric system utilizes the strong light-collecting ability and high efficiency of multimode optical fiber, as well as the strong spatial filtering effect and the ability to construct a reference of single-mode optical fiber, to perform interferometric synthesis of the two, so as to realize the metrological detection of the wavefront of the measured mirror and the high-throughput and high-efficiency detection of the system.

4. The large-aperture splicing mirror curvature radius detection system based on photonic leads as described in claim 1, characterized in that, The system also includes a detector end, which uses a multimode photonic lead to construct an optical circulator to achieve high-efficiency detection of the beam reflected from the mirror under test at the input end.

5. The large-aperture splicing mirror curvature radius detection system based on photonic leads as described in claim 2, characterized in that, The aperture encoding module includes multiple encoding units, and the distribution weight of the projected light intensity in different directions can be changed by adjusting the encoding mode.

6. The large-aperture splicing mirror curvature radius detection system based on photonic leads as described in claim 3, characterized in that, The interference system module includes a multimode fiber unit, a single-mode fiber unit, and a beam combining unit. The beam combining unit is used to interferometrically combine the beams output by the multimode fiber unit and the single-mode fiber unit.

7. The large-aperture splicing mirror curvature radius detection system based on photonic leads as described in claim 4, characterized in that, The optical circulator includes an input end, a detection end, and a reflection end. The reflection end is used to receive the light beam reflected by the mirror under test and transmit it to the detection end.

8. The large-aperture splicing mirror curvature radius detection system based on photonic leads as described in claim 1, characterized in that, When the curvature calculation module performs segmented fitting on the segmented test mirror, it independently calculates the curvature radius of the corresponding region based on the interference fringe characteristics of each segment.

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