CN-116734767-B - Aspheric surface characterization method based on spherical wave single lens zero compensation detection light path

CN116734767BCN 116734767 BCN116734767 BCN 116734767BCN-116734767-B

Abstract

The invention relates to the technical field of optical aspheric surfaces, in particular to an aspheric surface characterization method based on a spherical wave single lens zero compensation detection light path, which is characterized in that aspheric surfaces are characterized by using various parameters required by a zero compensation detection system with an interferometer incident wavefront being a spherical wave and a compensator being a single lens according to a ray tracing method, a Snell's law and an aplanatic principle based on a zero compensation detection principle by taking aspheric surface detection as a guide, and is a type of aspheric surfaces customized according to the characterization method, namely zero aspheric surfaces. The aspheric surface characterization method can obtain detection related data at the stage of designing an optical system, and can modulate and restrict the characterization parameters of the zero aspheric surface according to imaging requirements, so that the purposes of balancing factors such as imaging quality of the system, aspheric surface shape structure, compensator, rationality of a detection light path and the like are achieved, and the function that aspheric surface design can be detected is realized.

Inventors

MA TAO
ZENG XINYUE
ZHANG YULU

Assignees

苏州大学

Dates

Publication Date: 20260508
Application Date: 20230531

Claims (10)

1. An aspherical characterization method based on spherical wave single lens zero compensation detection light path is characterized by comprising the following steps: in a zero compensation detection system in which an incident wavefront of an interferometer is set to be a spherical wave and a compensator is a single lens compensator, a standard spherical mirror of the interferometer The number is Wherein Is the back focal length of the standard spherical mirror of the interferometer, The front and back surface curvature radius of the single lens compensator is as follows And The center thickness of the single lens compensator is Refractive index of single lens compensator material is The distance between the interferometer standard spherical mirror and the single lens compensator is The distance between the single lens compensator and the aspheric surface is ; In the zero compensation detection system, the detection light is detected by any point on the standard spherical mirror of the interferometer Point emergent light respectively intersecting with front and rear surfaces of the single lens Dots and The point is refracted by the single lens and then intersected with the aspheric surface Setting the emergent height of the detection light on the standard spherical mirror of the interferometer as Taking the surface shape as a parameter in the aspheric surface shape, In the caliber interval of the standard spherical mirror of the interferometer The inside is a continuous variable; When each parameter in the zero compensation detection system is fixed, the detected light rays are at any height Incident by Point to point The spot light processes are the same at the moment The track function of the point is an aspheric formula characterized by a single lens compensator, and the parameter expression of the general form is as follows: ; The single lens compensator and the aspheric surface form a zero spherical aberration system, the system follows the aplanatic principle, two detection light rays are selected, and one detection light ray is taken as the center point of a standard spherical mirror passing through the interferometer On-axis rays of the point, the path is: , wherein, The point is the vertex of the front surface of the single lens compensator, The point is the vertex of the back surface of the single lens compensator, The point is the central vertex of the aspheric surface, and the corresponding optical path of the on-axis light is ; The other detection ray is a parameter trace ray, an off-axis ray and a path According to the parameter of the zero compensation detection system, determining that the corresponding optical path of the parameter tracking light is Wherein Is that Dots and dots The distance between the points is such that, Is that Dots and dots The distance between the points is such that, Is used for refracting light Intersection point on optical axis Dots and dots The distance between the points is such that, Is used for refracting light Intersection point on optical axis Dots and dots The distance between the points; According to the principle of aplanatism, there are Obtaining On a point and an aspherical surface The distance between the points is ; To be used for The point is the origin of coordinates, and any point on the aspheric surface The trajectory equation of (a), i.e. the surface shape expression of the null aspheric surface, is ; Wherein the method comprises the steps of Is the included angle between the refractive light of the back surface of the single lens compensator and the optical axis, For the intersection point of the refractive light rays of the rear surface of the single lens compensator and the optical axis to the vertex of the rear surface of the single lens compensator The zero aspheric surface is a rotationally symmetrical curved surface, and the maximum effective caliber is determined by the actual light-transmitting caliber of the standard spherical mirror of the interferometer.
2. The method for characterizing an aspherical surface based on a spherical wave single lens zero compensation detection light path according to claim 1, wherein the determining the corresponding optical path of the parameter tracking light according to the parameter of the zero compensation detection system comprises: Detecting light at a height of The standard spherical mirror of the interferometer is used for incidence, and the object distance is obtained according to the detection light path Included angle between incident light and optical axis Known the angle between the incident light and the optical axis According to sine theorem, obtaining the included angle between the detected light and the normal line of the front surface of the single lens compensator Obtaining the refraction angle of light ray on the front surface of the single lens compensator according to the Snell's law ; Thereby obtaining the included angle between the refractive light of the front surface of the single lens compensator and the optical axis And the intersection point of the refraction light of the front surface of the single lens compensator on the optical axis reaches the vertex of the front surface of the single lens compensator Distance of (2) Obtaining the distance between the intersection point of the incident light on the back surface of the single lens compensator on the optical axis and the vertex of the back surface of the single lens compensator according to the transition formula of the conjugate spherical system And the included angle between the incident light and the optical axis on the back surface of the single lens compensator ; The included angle between the incident light and the optical axis on the back surface of the single lens compensator is known According to sine theorem, obtaining the included angle between the incident light ray on the rear surface of the single lens compensator and the normal line of the rear surface of the single lens compensator Obtaining the refraction angle of light ray on the back surface of the single lens compensator according to the Snell's law ; Thereby obtaining the included angle between the refractive light of the rear surface of the single lens compensator and the optical axis And the intersection point of the refractive light rays of the rear surface of the single lens compensator and the optical axis reaches the vertex of the rear surface of the single lens compensator Distance of (2) ; Therefore, the intersection point of the detection light and the front and rear surfaces of the single lens compensator 、 Is given by the radial coordinate of , ; Then Dots and dots The distance between the points is ; Dots and dots The distance between the points is Refractive ray Intersection point on optical axis Dots and dots The distance between the points is 。
3. The method for characterizing an aspherical surface based on a spherical wave single lens zero compensation detection optical path according to claim 2, wherein the detection light is of a height The standard spherical mirror of the interferometer is used for incidence, and the object distance is obtained according to the detection light path Included angle between incident light and optical axis 。
4. The method for characterizing an aspherical surface based on a spherical wave single lens zero compensation detection optical path as defined in claim 2, wherein the known included angle between the incident light and the optical axis According to the sine theorem, there are Detecting the angle between the light and the normal line of the front surface of the single lens compensator 。
5. The method for characterizing an aspherical surface of a spherical wave-based single lens zero compensation detection optical path according to claim 2, wherein the refraction angle of the detection light at the front surface of the single lens compensator is obtained according to snell's law 。
6. The method for characterizing an aspherical surface based on a spherical wave single lens zero compensation detection optical path according to claim 2, wherein the included angle between the refractive light ray and the optical axis of the front surface of the single lens compensator And the intersection point of the refraction light of the front surface of the single lens compensator on the optical axis reaches the vertex of the front surface of the single lens compensator Distance of (2) 。
7. The method for characterizing an aspherical surface based on a spherical wave single lens zero compensation detection optical path according to claim 2, wherein the distance between the intersection point of the incident light ray on the rear surface of the single lens compensator and the vertex of the rear surface of the single lens compensator is obtained according to a transition formula of a conjugate spherical system And the included angle between the incident light and the optical axis on the back surface of the single lens compensator 。
8. The method for characterizing an aspherical surface based on a spherical wave single lens zero compensation detection optical path according to claim 2, wherein an included angle between an incident ray on a rear surface of the known single lens compensator and an optical axis is According to the sine theorem, there are The incident light ray on the back surface of the single lens compensator forms an included angle with the normal line of the back surface of the single lens compensator 。
9. The method for characterizing an aspherical surface of a spherical wave-based single lens zero compensation detection optical path according to claim 2, wherein the refraction angle of the detection light at the rear surface of the single lens compensator is obtained according to snell's law 。
10. The method for characterizing an aspherical surface based on a spherical wave single lens zero compensation detection optical path according to claim 2, wherein the included angle between the refractive light ray and the optical axis of the rear surface of the single lens compensator And the intersection point of the refractive light rays of the rear surface of the single lens compensator and the optical axis reaches the vertex of the rear surface of the single lens compensator Distance of (2) 。

Description

Aspheric surface characterization method based on spherical wave single lens zero compensation detection light path Technical Field The invention relates to the technical field of optical aspheric surfaces, in particular to an aspheric surface characterization method based on spherical wave single lens zero compensation detection light paths. Background The optical aspheric surface is an important optical surface shape, and compared with a spherical lens, the aspheric lens can control the trend and focusing effect of light more accurately, so that higher optical performance and smaller imaging distortion are realized, and therefore, the optical aspheric lens is applied in a wide field. The production process of aspherical lenses generally includes three stages of design, processing and inspection. In the design stage of the aspheric surface, the characterization mode of the aspheric surface is mostly designed as a guide, and the surface shape is changed through the mathematical description of the aspheric surface, so that the degree of freedom of optimization is increased, and various aberrations of the system are corrected to obtain an optimal design scheme. The detection of the aspherical surface is used to check whether the optical performance of the aspherical lens meets the design requirement after design and processing, and to determine the surface shape and error thereof. The zero compensation method is an effective aspheric surface full-surface detection method, and the compensator required by the method is generally required to have a simple structure, otherwise, errors in machining and assembling the compensator can cause the zero compensation method to lose detection accuracy. When zero compensation method is adopted as the detection means, the design of the compensator is closely related to the aspheric surface shape. However, because the aspheric lens is a common part of the system optical path and the zero compensation detection optical path, and in actual production, the system optical path design and the zero compensation detection optical path design are sequentially and unidirectionally performed, the zero compensation detection optical path design cannot provide feedback for the system optical path design, and the zero compensation detection optical path cannot be optimized by effectively utilizing the latitude of the system optical path, so that the minimum deviation of the aspheric surface shape may cause the compensator structure to become very complex, and the zero compensation method is not feasible. Disclosure of Invention Therefore, the invention aims to solve the technical problems that in the prior art, because the design of the aspheric surface is prior to processing and detection, when the zero compensation method is used for detection, the detection cannot provide feedback for the design, and the tolerance of the system optical path structure cannot be effectively utilized to finely adjust the detection scheme, so that the detection scheme is very complex under partial conditions, and the detection precision is reduced. In order to solve the technical problems, the invention provides an aspherical characterization method based on spherical wave single lens zero compensation detection light path, comprising the following steps: Setting the incident wavefront of the interferometer as spherical waves, wherein in a zero compensation detection system with a single compensator, the F number of a standard spherical lens of the interferometer is R/D, wherein R is the back focal length of the standard spherical lens, D is the light transmission caliber of the standard spherical lens, the curvature radiuses of the front surface and the back surface of the single lens compensator are R 1 and R 2, the center thickness of the single lens compensator is D, the refractive index of a single lens compensator material is n, the distance between the standard spherical lens of the interferometer and the single lens compensator is L 1, and the distance between the single lens compensator and an aspheric surface is L 2; In the zero compensation detection system, detection light is emitted from an arbitrary point A on the standard spherical mirror of the interferometer, respectively intersects with the front and rear surfaces of the single lens at a point B and a point C, and is refracted by the single lens and then intersects with an aspheric surface at a point Q; When each parameter in the zero compensation detection light path is fixed, the detection light enters at any height h, the light paths from the point A to the point Q are the same, the track function of the point Q is an aspheric surface formula represented by the single lens compensator, and the general form parameter expression is as follows: The single lens compensator and the aspheric surface form a zero spherical aberration system, the system selects two detection light rays according to an aplanatic principle, one detection light r