WO2018035957A1

WO2018035957A1 - Aspheric compensating lens, and aspheric optical detection system and method

Info

Publication number: WO2018035957A1
Application number: PCT/CN2016/103514
Authority: WO
Inventors: 高松涛; 苗二龙; 武东城; 隋永新; 杨怀江
Original assignee: 中国科学院长春光学精密机械与物理研究所
Priority date: 2016-08-23
Filing date: 2016-10-27
Publication date: 2018-03-01
Also published as: CN106247929A

Abstract

An aspheric compensating lens (S1), and an aspheric optical detection system and method. The aspheric optical detection system comprises: an aspheric compensating lens (S1) comprising a reference surface (S2) and at least one compensating surface, wherein the reference surface (S2) is used to reflect light incident along a normal line to the reference surface (S2) and then return same along the original path so as to form reference light; light penetrating through the reference surface (S2) and the at least one compensating surface forms an aspheric wave matching an aspheric surface to be detected (S3), and light in the aspheric wave is incident along a normal line to the aspheric surface, and returns along the original light path after being reflected by the aspheric surface to be detected (S3) so as to form light to be detected; and an interferometer for generating a planar wave and emitting same to the aspheric compensating lens (S1), and detecting, at the same time, an interference pattern formed by the reference light and the light to be detected so as to detect the aspheric surface to be detected (S3). By arranging the reference surface (S2) inside an aspheric compensating lens (S1), the structure of an aspheric detection optical path is simplified.

Description

Aspherical compensation mirror, aspherical optical detection system and method

Technical field

The invention belongs to the technical field of optical design, and in particular relates to an aspherical compensation mirror, an aspheric optical detection system and a method.

Background technique

In the prior art, when detecting a high-precision aspherical surface, it is often necessary to use a compensating mirror or a computational hologram to convert the spherical wave emitted by the interferometer into an aspherical wave matching the aspherical surface to be tested, thereby realizing zero-position detection. In this case, it is often necessary to insert a compensation mirror or a computational hologram into the detection optical path, resulting in a complicated optical path structure, and the use adjustment is very inconvenient.

Based on this, it is necessary to provide an aspherical optical detection method and system to realize convenient and quick detection of aspheric surfaces.

Summary of the invention

To achieve the above object, the present invention provides an aspherical compensation mirror, an aspherical optical detection system and method.

According to a first aspect of the present invention, an aspherical optical detection system is provided, comprising:

An aspherical compensating mirror comprising a reference surface and at least one compensating surface; the reference surface is configured to reflect light incident along a normal to the reference plane and return the original path to form reference light; and pass the reference surface And the light of the at least one compensation surface forms an aspheric wave matching the aspheric surface to be tested, and the light in the aspheric wave is incident along an aspheric normal line, and is reflected along the original optical path after the aspheric surface to be tested Return to form the light to be measured;

The interferometer is configured to generate a plane wave and exit to the aspherical compensation mirror, and simultaneously detect the interference fringes formed by the reference light and the to-be-measured light to detect the aspheric surface to be tested.

Wherein, the aspherical compensating mirror further comprises an etalon interface matched with the interferometer for mounting on a corresponding interface of the interferometer.

Wherein, the aspherical compensation mirror comprises a plurality of lenses, one of the mirrors of the lens serves as a reference surface, and the remaining mirrors are compensation surfaces.

Wherein, the reference surface and the compensation surface are plane or spherical.

Wherein the aspherical compensation mirror comprises a planar lens and a concave lens; the planar lens and the concave lens are sequentially disposed along the optical path, and the second plane of the planar lens is a reference surface, the first mirror surface and the concave lens of the planar lens The two mirrors are the compensation surfaces.

The aspherical compensation mirror includes a first lens, a second lens, and a third lens. The first lens, the second lens, and the third lens are sequentially disposed along a direction of the optical path, and the front and rear mirrors of the first lens and the second lens And the second mirror surface of the third lens is a compensation surface, and the first mirror surface of the third lens is a reference surface. 7. The system of claim 1 wherein the aspherical compensating mirror is mounted on the interferometer via an etalon interface.

According to a second aspect of the present invention, there is provided an aspherical compensating mirror for use in an aspheric optical detecting system, comprising:

a reference surface and at least one compensation surface; the reference surface is configured to reflect light incident along a normal to the reference surface and return the original path to form reference light; and transmit the reference surface and the at least one compensation surface The light forms an aspherical wave that matches the aspherical surface to be measured. The light in the aspherical wave is incident along the aspheric normal and is reflected along the original optical path after the aspherical surface to be measured to form a light to be measured.

Wherein the aspherical compensation mirror comprises a planar lens and a concave lens; the planar lens and the concave lens are sequentially disposed along the optical path, and the second mirror surface of the planar lens is a reference surface, the first mirror surface and the concave lens of the planar lens The two mirrors are the compensation surfaces.

Wherein the aspherical compensation mirror comprises a first lens, a second lens and a third lens, The first lens, the second lens, and the third lens are sequentially disposed along the direction of the optical path, the front and rear mirror surfaces of the first lens and the second lens, and the second mirror surface of the third lens are compensation surfaces, and the first mirror surface of the third lens is Reference surface.

Wherein, the aspherical compensation mirror is mounted on the interferometer through an etalon interface.

According to a third aspect of the present invention, an aspherical optical detection method is provided, comprising:

Step 201: The interferometer emits a plane wave;

Step 202: A plane wave emitted by the interferometer is incident on an aspherical compensation mirror, the aspherical compensation mirror includes a reference surface and at least one compensation surface; and a portion of the light incident along a normal to the reference surface is reflected by the reference surface Returning from the original path to form reference light; light passing through the reference surface and the at least one compensation surface forms an aspherical wave matching the aspheric surface to be tested; the light in the aspherical wave is incident along an aspheric normal, and After being returned by the aspherical surface to be tested, returning along the original optical path to form a light to be measured;

Step 203: The interferometer detects interference fringes formed after the reference light and the light to be measured interfere to realize zero position detection of the aspheric surface to be tested.

The technical effect obtained by the above technical solution is that the reference surface is disposed inside the aspherical compensation mirror, and the aspherical compensation mirror can be directly mounted on the interferometer through the etalon interface, without using the spherical wave emitted by the interferometer It is transformed into an aspherical wave matching the aspherical surface to be tested, thereby simplifying the detection optical path structure of the aspherical surface, and realizing the convenient and quick detection of the aspherical surface.

DRAWINGS

1 is a block diagram of an aspherical optical detection system in accordance with an embodiment of the present invention;

2 is a schematic diagram showing optical design results of Embodiment 1 in an aspherical optical detecting system according to an embodiment of the present invention;

3 is a schematic view showing the assembly result of Embodiment 1 in the aspherical optical detecting system provided in an embodiment of the present invention;

4 is a schematic diagram showing optical design results of Embodiment 2 in an aspheric optical detecting system according to an embodiment of the present invention;

5 is a schematic diagram showing the assembly result of Embodiment 2 in the aspherical optical detecting system provided in an embodiment of the present invention;

Figure 6 is a flow chart of the aspherical optical detection method of the present invention.

detailed description

The present invention will be further described in detail below in conjunction with the drawings and specific embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

As shown in FIG. 1, the present invention provides an aspherical optical detection system including:

The aspherical compensation mirror S1 includes a reference surface S2 and at least one compensation surface; the reference surface is configured to reflect the light incident along the normal of the reference surface and return the original path to form reference light; The reference surface and the light of the at least one compensation surface form an aspherical wave matching the aspherical surface to be tested, the light in the aspherical wave is incident along an aspheric normal, and the aspherical reflection is detected by the aspherical surface to be tested The original light path returns to form the light to be measured;

The interferometer is configured to generate a plane wave and exit to the aspherical compensation mirror S1, and detect interference fringes formed by the reference light and the light to be detected to detect the aspheric surface to be tested.

Wherein, the aspherical wave matching the aspherical surface to be tested means that all of the rays incident on the aspherical surface to be tested in the aspherical wave are incident along a normal line of the aspherical surface to be tested.

In the conventional aspherical optical detection system, the reference surface is mounted on the interferometer in a separate standard mirror form, and in the present invention, the reference surface S2 is disposed inside the aspherical compensation mirror S1, and the aspheric surface. The compensation mirror S1 is formed as a whole, and the reference plane S2 and the aspherical compensation mirror S1 need not be separately adjusted when the optical path is adjusted, thereby saving the detection time, and the reference plane S2 may be one of the surfaces of the aspherical compensation mirror S1. This saves costs.

In a possible embodiment, the aspherical compensation mirror S1 has an etalon interface that matches the interferometer, and the aspherical compensation mirror S1 is connected to the interferometer through the etalon interface; In this way, the aspherical compensation mirror with a reference surface The S1 can be mounted directly on the interferometer without the need to provide separate mounting equipment.

In this embodiment, the plane wave emitted by the interferometer is converted into an aspheric wave matching the aspheric surface S3 to be tested after passing through the aspherical compensation mirror S1, so that all the rays entering the aspheric surface to be tested are along The normal incidence of the aspheric surface to be tested is returned along the original optical path after the aspherical surface to be measured, and the formed light to be measured interferes with the reference light to form an interference fringe, and the interferometer detects the Interference fringes enable zero detection of aspheric surfaces.

In this embodiment, the structure and parameters of the aspherical compensation mirror S1 are determined by the aspherical surface to be tested, and specifically need to be designed according to the structure of the aspherical surface to be tested, which needs to include a reference surface, and can pass through the aspherical compensation mirror. The light emitted by S1 is incident on the aspheric surface to be tested along a normal line on the aspheric surface to be tested.

In an embodiment, the aspherical compensation mirror S1 includes a reference surface and a plurality of compensation surfaces, and the reference surface and the plurality of compensation surfaces are planar or spherical. a part of the light wave emitted by the interferometer is incident on the reference surface along the normal line of the reference surface, and then returns to the original path to form reflected light; the plane wave emitted by the interferometer transmits the reference surface and the The light rays after the plurality of compensation surfaces form an aspherical wave, and the light rays in the aspherical wave are incident on the aspheric surface to be tested along a normal line of the aspherical surface to be tested, and the aspherical surface reflection is performed The rear original path returns to form a light to be measured and interferes with the reference light.

In an embodiment, as shown in FIG. 2, the aspherical compensation mirror S1 includes a planar lens and a concave lens, wherein the second mirror surface (ie, the light exit surface) of the planar lens serves as a reference surface (in other implementations) In an example, the first mirror surface of the planar lens can serve as a reference surface), and a portion of the light incident perpendicularly to the second mirror surface is returned to form a reference light; and light passing through the planar lens enters the concave lens; The two spherical surfaces of the concave lens serve as compensation surfaces such that light passing through the planar lens forms an aspherical wave and is incident on the aspheric surface to be tested along a normal line of the aspheric surface S3 to be measured.

Fig. 3 is a view showing the configuration of the aspherical compensating mirror in the above embodiment. As shown in FIG. 3, the aspherical compensation mirror includes a first portion P1 and a second portion P2, wherein the first portion is the The etalon interface of the aspherical compensating mirror can be directly mounted on the interferometer; the second portion P2 is a mirror group portion including a planar lens and a concave lens; and P3 is directed to the aspherical compensated reference surface.

In another embodiment, as shown in FIG. 4, the aspherical compensation mirror S1 includes three lenses, along the direction of the optical path, the front and rear mirrors of the first and second lenses, and the second of the third lens. The mirror surface (ie, the light exit surface) is a compensation surface, wherein the first surface of the third lens (ie, the light incident surface) serves as the reference surface S2, and the plane wave emitted by the interferometer passes through the first lens and the second lens and is incident on the third surface. The reference surface of the lens, the light is incident along the normal of the reference surface, and is reflected by the reference surface to form reference light; and the light passing through the third lens passes through the compensation mirror to form an aspheric wave, and along the normal of the aspheric surface to be tested After incident, after the aspherical reflection to be measured, the original path returns to form a light to be measured.

Fig. 5 is a view showing the configuration of the aspherical compensating mirror in the above embodiment. As shown in FIG. 5, the aspherical compensation mirror includes a first portion P1 and a second portion P2, wherein the first portion is an etalon interface of the aspherical compensation mirror, and can be directly mounted on the interferometer; P2 is a mirror portion including three lenses; P3 points to the aspherically compensated reference plane.

The interferometer of the present invention may be an interferometer of ZYGO Corporation.

As shown in FIG. 6, the present invention also provides an aspheric optical detection method, which includes:

Step 201: The interferometer emits a plane wave;

Step 202: A plane wave emitted by the interferometer is incident on an aspherical compensation mirror, the aspherical compensation mirror includes a reference surface and at least one compensation surface; and a portion of the plane wave incident along a normal to the reference plane is After the reference surface is reflected, the original path returns to form reference light; and the light passing through the reference surface and the at least one compensation surface is converted into an aspheric wave matching the aspheric surface to be tested, so that the aspheric wave is All the light rays are incident along a normal line of the aspheric surface to be measured, and are reflected by the aspheric surface to be tested to form a light to be measured;

The implementation process of the design method and assembly method of the aspherical compensation mirror provided by the present invention will be explained below through specific embodiments.

Example 1:

Referring to Table 1, Table 1 is an aspherical equation parameter in Example 1. For the aspherical equations shown in Table 1, the aspherical compensation mirror can be obtained by the optical design software optimization using the design method of the present invention. The result is shown in FIG. 2, and FIG. 2 is an aspherical compensation mirror provided by the present invention. Schematic diagram of the optical design results of Example 1 of the design method design.

For the aspherical equation parameters shown in Table 1, the optical design results of the design method using the aspherical compensation mirror provided by the present invention are shown in Fig. 2. In Fig. 2, S1 is an aspherical compensation mirror, and S2 is a reference plane. , S3 is the aspherical surface to be tested. When designing the aspherical compensation mirror S1, the reference surface is placed inside the aspherical compensation mirror S1, and then the aspherical compensation mirror S1 is directly mounted on the etalon interface of the interferometer through the etalon interface. The position realizes convenient and quick detection of the aspherical surface S3 to be tested.

Referring to Table 2, Table 2 is the specific parameters of the aspherical compensating mirror designed in Embodiment 1, the parameter K is a quadratic constant, and the aspherical equation is as shown in the formula (1), wherein the surface number is from near the light incident. The directions are from 1 to 4, i.e., the first and second mirrors of the planar lens are numbered 1 and 2, and the first and second mirrors of the lens are numbered 3 and 4. Referring to FIG. 3, FIG. 3 is a schematic diagram showing the assembly result of Embodiment 1 of the design method of the aspherical compensation mirror provided by the present invention. In Fig. 3, P1 is the etalon interface of the aspherical compensation mirror, P2 is the mirror set in the aspherical compensation mirror, and P3 points to the reference plane.

Table 1 Equation parameters of the aspheric surface in Embodiment 1

通光口径(mm)Passage diameter (mm)	曲面半径R(mm)Surface radius R (mm)	KK
6565	-100.584-100.584	1.3298731.329873

Where z is the aspherical vector height and ρ is the radial coordinate of the aspherical surface.

Table 2 Optical parameters of the aspherical compensation mirror in Embodiment 1

Example 2:

Referring to Table 3, Table 3 is the aspherical equation parameter in Embodiment 2. For the aspherical equations shown in Table 3, using the design method discussed in the patent, the aspherical compensation mirror can be obtained by optical design software optimization. The result is shown in FIG. 4, and FIG. 4 is an aspherical compensation mirror provided by the present invention. A schematic diagram of the optical design result of the second embodiment of the design method design is the same as that of the first embodiment.

For the aspherical equation parameters shown in Table 3, the optical design results of the design method using the aspherical compensation mirror provided by the present invention are shown in Fig. 4. In Fig. 4, S1 is an aspherical compensation mirror, and S2 is an interferometer. The reference surface, S3 is the aspheric surface to be tested, the interferometer reference surface S2 is first set inside the aspherical compensation mirror S1, and then the aspherical compensation mirror S1 is directly installed on the etalon interface position of the interferometer through the etalon interface, thereby realizing treatment It is convenient and quick to test the aspherical surface S3.

Referring to Table 4, Table 4 is the specific parameters of the aspherical compensation mirror designed in Embodiment 2, where K is a quadratic constant, A4 is a 4th term coefficient, A6 is a 6th term coefficient, and A8 is a 8th term. The coefficient, aspherical equation is shown in equation (2). Referring to Fig. 5, Fig. 5 is a schematic view showing the assembly result of the embodiment 2 designed by the design method of the aspherical compensation mirror provided by the present invention. In Fig. 5, P1 is the etalon interface of the aspherical compensation mirror, P2 is the mirror of the aspherical compensation mirror, and P3 points to the reference plane.

Table 3 Equation parameters of the aspheric surface in Embodiment 2

Light aperture mm)

Curvature radius R (mm)

K

A4

A6

A8

72.5

-142.586

1.855450

5.6477E-8

6.107E-12

6.6230E-18

Table 4 Optical parameters of the aspherical compensation mirror in Embodiment 2

The design method of the aspherical compensating mirror provided by the invention provides that the reference surface is disposed inside the aspherical compensating mirror, and the aspherical compensating mirror can be directly mounted on the interferometer through the etalon interface, without converting the spherical wave emitted by the interferometer The aspherical wave matching the aspherical surface to be tested simplifies the aspherical detection optical path structure, and realizes convenient and quick detection of the aspherical surface.

The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and equivalent structural or equivalent functional changes made by the description of the present invention and the accompanying drawings may be directly or indirectly applied to other related technical fields. The same is included in the scope of patent protection of the present invention.

Claims

An aspheric optical inspection system comprising:

An aspherical compensating mirror comprising a reference surface and at least one compensation surface, wherein:

The reference surface is configured to reflect light incident along a normal line of the reference surface and return the original path to form reference light;

The light passing through the reference surface and the at least one compensation surface forms an aspheric wave matching the aspheric surface to be tested, and the light in the aspheric wave is incident along an aspheric normal and passes through the non-spherical After the spherical reflection, return along the original light path to form the light to be measured;

The interferometer is configured to generate a plane wave and exit to the aspherical compensation mirror, and simultaneously detect the interference fringes formed by the reference light and the to-be-measured light to detect the aspheric surface to be tested.
The system of claim 1 wherein said aspherical compensating mirror further comprises an etalon interface mated with said interferometer for mounting on a corresponding interface of said interferometer.
The system of claim 1 wherein said aspherical compensating mirror comprises a plurality of lenses, one of said mirrors being a reference surface and the remaining mirrors being a compensating surface.
The system of claim 1 wherein said reference surface and compensation surface are planar or spherical.
The system of claim 1 wherein:

The aspherical compensation mirror includes a planar lens and a concave lens;

The planar lens and the concave lens are sequentially disposed along the optical path, and the second mirror surface of the planar lens along the optical path direction is a reference surface, and the first mirror surface of the planar lens along the optical path direction and the two mirror surfaces of the concave lens are compensation surfaces.
The system of claim 1 wherein:

The aspherical compensation mirror includes a first lens, a second lens, and a third lens;

The first lens, the second lens, and the third lens are sequentially disposed along a direction of the optical path;

The front and rear mirror faces of the first lens and the second lens and the second mirror face of the third lens are compensation faces, and the first mirror face of the third lens is a reference face.
The system of claim 1 wherein said aspherical compensating mirror is mounted on said interferometer via an etalon interface.
An aspherical compensating mirror, wherein the aspherical compensating mirror is used in an aspheric optical detecting system, including

a reference plane and at least one compensation surface, wherein:

The reference surface is configured to reflect light incident along a normal line of the reference surface and return the original path to form reference light;

The light passing through the reference surface and the at least one compensation surface forms an aspheric wave matching the aspheric surface to be tested, and the light in the aspheric wave is incident along an aspheric normal and passes through the non-spherical After the spherical reflection, it returns along the original light path to form the light to be measured.
The aspherical compensating mirror of claim 8 wherein said aspherical compensating mirror further comprises an etalon interface mated to the interferometer for mounting on a corresponding interface of said interferometer.
The aspherical compensating mirror according to claim 8, wherein the aspherical compensating mirror comprises a plurality of lenses, one of the mirror faces of the lens serves as a reference surface, and the remaining mirror faces are compensation faces.
The aspherical compensating mirror according to claim 8, wherein the reference surface and the compensating surface are planar or spherical.
The aspherical compensator of claim 8 wherein:

The aspherical compensation mirror includes a planar lens and a concave lens;

The planar lens and the concave lens are sequentially disposed along the optical path, and the second mirror surface of the planar lens is a reference surface, and the first mirror surface of the planar lens and the two mirror surfaces of the concave lens are compensation surfaces.
The aspherical compensator of claim 8 wherein:

The aspherical compensation mirror includes a first lens, a second lens, and a third lens;

The first lens, the second lens, and the third lens are sequentially disposed along a direction of the optical path;

The front and rear mirror faces of the first lens and the second lens and the second mirror face of the third lens are compensation faces, and the first mirror face of the third lens is a reference face.
The aspherical compensating mirror of claim 8 wherein said aspherical compensating mirror is mounted on said interferometer via an etalon interface.
An aspheric optical detection method comprising:

Step 201: The interferometer emits a plane wave;

Step 202: A plane wave emitted by the interferometer is incident on an aspherical compensation mirror, the aspherical compensation mirror includes a reference surface and at least one compensation surface; and a portion of the light incident along a normal to the reference surface is reflected by the reference surface Returning from the original path to form reference light; light passing through the reference surface and the at least one compensation surface forms an aspherical wave matching the aspheric surface to be tested; the light in the aspherical wave is incident along an aspheric normal, and After being returned by the aspherical surface to be tested, returning along the original optical path to form a light to be measured;

Step 203: The interferometer detects interference fringes formed after the reference light and the light to be measured interfere to realize zero position detection of the aspheric surface to be tested.