Compensator for high-precision small-caliber large-curvature radius convex aspherical surface shape detection

Abstract

The application discloses a compensator for high-precision small-caliber large-curvature-radius convex aspherical surface shape detection, and the high-precision small-caliber large-curvature-radius convex aspherical surface is a to-be-detected aspherical surface; the compensator is a rotationally symmetrical structure as a whole, three single lenses are sequentially arranged in the compensator along the same optical axis to form a lens group, the three single lenses are all polished spherical surfaces, and are sequentially a first lens, a second lens and a third lens along the light incidence direction; the to-be-detected aspherical surface is arranged behind the third lens along the light incidence direction; and the compensator converts the plane wave emitted by an interferometer into an aspherical wave matched with the to-be-detected aspherical surface, so that zero-position detection of the to-be-detected aspherical surface is realized. The application has the advantages of simple structure, easy processing and convenient use.

Description

Technical Field

[0001] This invention relates to a compensator for surface shape detection, and more particularly to a compensator for high-precision surface shape detection of small-diameter, large-radius-curvature convex aspherical surfaces. Background Technology

[0002] In optical design, aspherical surfaces can improve system resolution, expand the field of view, and simplify system structure. High-precision aspherical surfaces are increasingly widely used in space optics. Although aspherical surfaces have excellent optical properties, high-precision aspherical surface shape inspection, especially high-precision convex aspherical surface shape inspection, has always been a challenge in the field of optical inspection. Most existing compensator structures are designed for compensating mirror assemblies for large-aperture concave aspherical surfaces, and these compensating mirror assemblies cannot achieve high-precision convex aspherical surface shape inspection.

[0003] The key to achieving high-precision convex aspherical surface shape detection lies in designing a set of compensation mirrors for the aspherical surface under test. A well-structured initial structure of the compensation mirror set is crucial for optimizing the optical path of aspherical interferometric detection. The compensation mirror set typically consists of two or three spherical mirrors, converting the spherical waves emitted by the interferometer into aspherical waves that match the aspherical surface, thereby achieving zero-position detection of the aspherical surface. Therefore, providing an initial structure suitable for high-precision convex aspherical surface shape detection compensation mirrors is a critical issue in the field of interferometric detection. Summary of the Invention

[0004] The purpose of this invention is to provide a compensator for high-precision detection of convex aspherical surfaces with small diameter and large radius of curvature, so as to solve the problems mentioned in the background art.

[0005] To achieve the above-mentioned objectives, this invention provides a compensator for high-precision detection of the surface shape of a small-diameter, large-radius convex aspherical surface, wherein the high-precision small-diameter, large-radius convex aspherical surface is the aspherical surface to be measured; the compensator is a rotationally symmetric structure, and three single lenses are arranged sequentially along the same optical axis to form a lens group inside the compensator. The three single lenses are all polished spherical surfaces, and are arranged sequentially as a first lens, a second lens, and a third lens along the incident direction of light.

[0006] The aspherical surface to be tested is positioned behind the third lens along the direction of light incidence.

[0007] The compensator converts the plane wave emitted by the interferometer into an aspherical wave that matches the aspherical surface under test, thereby realizing the zero-position detection of the aspherical surface under test.

[0008] Furthermore, the first lens has a left surface radius of curvature of 71.428 mm, a right surface radius of curvature of 116.2 mm, and a thickness of 16.137 mm; the second lens has a left surface radius of curvature of 51.62 mm, a right surface radius of curvature of 78.048 mm, and a thickness of 16.598 mm; the third lens has a left surface radius of curvature of 47.6 mm, a right surface radius of curvature of 51.881 mm, and a thickness of 14.427 mm; the interval between the first and second lenses is 45.552 mm; the interval between the second and third lenses is 67.641 mm; and the distance from the third lens to the aspherical surface to be measured is 102.996 mm.

[0009] Furthermore, in the detection optical path, the light-emitting surface is close to the aspherical surface under test, and the light-incident surface is close to the interferometer lens.

[0010] Furthermore, the compensator operates at a wavelength of 632.8 nm.

[0011] Furthermore, the compensator operates using parallel light incident.

[0012] Furthermore, the total length of the compensator system is 230mm, and the maximum aperture of the three single lenses is 55mm.

[0013] Furthermore, all three single lenses are made of fused silica material.

[0014] Furthermore, this device is manufactured using an optical cold processing technique.

[0015] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0016] This invention provides an initial design structure for a compensator used for high-precision detection of small-diameter, large-radius-curvature convex aspherical surfaces. The compensator is a lens group consisting of three single lenses, which converts a plane wave emitted from an interferometer into an aspherical wave matching the aspherical surface being measured, thereby enabling the detection of the aspherical surface shape. This invention has a simple structure, is easy to manufacture, and is convenient to use. Attached Figure Description

[0017] Figure 1 This is a single-lens group for a compensator used for high-precision detection of convex aspherical surfaces with small diameter and large radius of curvature.

[0018] Figure 2 This is a schematic diagram of the compensator in use.

[0019] In the figure, 1 is the first lens, 2 is the second lens, 3 is the third lens, and 4 is the aspherical surface to be tested. Detailed Implementation

[0020] The advantages of the present invention are further illustrated below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that the following detailed description is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention.

[0021] like Figure 1 The image shows the core component of the compensator for high-precision detection of small-diameter, large-radius-curvature convex aspherical surfaces of the present invention. It consists of a lens group composed of three single lenses, which are fixed sequentially along the same axis. All three single lenses are polished spherical surfaces made of fused silica material. Along the direction of light incidence, they are arranged sequentially as follows: first lens 1, second lens 2, third lens 3, and the aspherical surface to be measured 4. The first lens 1 has a left surface radius of curvature of 71.428 mm, a right surface radius of curvature of 116.2 mm, and a thickness of 16.137 mm. The second lens 2 has a left surface radius of curvature of 51.62 mm, a right surface radius of curvature of 78.048 mm, and a thickness of 16.598 mm. The third lens 3 has a left surface radius of curvature of 47.6 mm, a right surface radius of curvature of 51.881 mm, and a thickness of 14.427 mm. The distance between the first lens 1 and the second lens 2 is 45.552 mm, the distance between the second lens 2 and the third lens 3 is 67.641 mm, and the distance from the third lens 3 to the aspherical surface under test is 102.996 mm. The compensator converts the plane wave emitted by the interferometer into an aspherical wave that matches the small-diameter, large-radius-curvature convex aspherical surface, thereby achieving zero-position detection of the aspherical surface under test. The entire compensator is a rotationally symmetric structure and is manufactured using optical cold-working technology. The compensator system has a total length of 230mm and three single lenses with a maximum aperture of 55mm.

[0022] like Figure 2 The diagram shows the detection optical path in this embodiment during use. In this path, the compensator's output surface is close to the high-precision, small-diameter, large-radius-curvature convex aspherical surface 4 to be measured, while its incident surface is close to the interferometer lens. Parallel light is used during operation. The compensator operates at a wavelength of 632.8 nm.

[0023] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A compensator for high-precision detection of the surface shape of a small-diameter, large-radius convex aspherical surface, wherein the high-precision, small-diameter, large-radius convex aspherical surface is the aspherical surface to be measured; characterized in that, The compensator has a rotationally symmetrical structure. Inside the compensator, three single lenses are arranged in sequence along the same optical axis to form a lens group. The three single lenses are all polished spherical surfaces and are arranged in sequence as the first lens, the second lens, and the third lens along the incident direction of light. The aspherical surface to be tested is positioned behind the third lens along the direction of light incidence. The compensator converts the plane wave emitted by the interferometer into an aspherical wave that matches the aspherical surface under test, thereby realizing the zero-position detection of the aspherical surface under test. The first lens has a left surface radius of curvature of +71.428 mm, a right surface radius of curvature of +116.2 mm, and a thickness of 16.137 mm. The second lens has a left surface radius of curvature of -51.62 mm, a right surface radius of curvature of -78.048 mm, and a thickness of 16.598 mm. The third lens has a left surface radius of curvature of -47.6 mm, a right surface radius of curvature of -51.881 mm, and a thickness of 14.427 mm. The interval between the first and second lenses is 45.552 mm, the interval between the second and third lenses is 67.641 mm, and the distance from the third lens to the aspherical surface to be measured is 102.996 mm.

2. The compensator for high-precision detection of convex aspherical surfaces with small diameter and large radius of curvature as described in claim 1, characterized in that, In the detection optical path, the light-emitting surface is close to the aspherical surface to be measured, and the light-incident surface is close to the interferometer lens.

3. The compensator for high-precision detection of convex aspherical surfaces with small diameter and large radius of curvature according to claim 2, characterized in that, The compensator operates at a wavelength of 632.8 nm.

4. The compensator for high-precision detection of convex aspherical surfaces with small diameter and large radius of curvature according to claim 2, characterized in that, The compensator operates using parallel light incident.

5. The compensator for high-precision detection of convex aspherical surfaces with small diameter and large radius of curvature according to claim 2, characterized in that, The total length of the compensator system is 230mm, and the maximum aperture of the three single lenses is 55mm.

6. The compensator for high-precision detection of convex aspherical surfaces with small diameter and large radius of curvature according to claim 2, characterized in that, All three single lenses are made of fused silica.

7. The compensator for high-precision detection of convex aspherical surfaces with small diameter and large radius of curvature according to claim 2, characterized in that, The compensator is manufactured using an optical cold processing technique.

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