Device for measuring surface profile of aspheric surface optical element in large dynamic range

Abstract

The invention relates to a device for measuring the surface profile of an aspheric surface optical element in a large dynamic range. The device utilizes a subaperture segmentation diaphragm to form a specific incident light beam, the incident light beam is projected onto the surface of the detected aspheric surface optical element, an image formed by the reflected light beam of the incident light beam is received and collected, an aberration mode algorithm is utilized for recovering information of the surface profile of the detected aspheric surface optical element or surface error information. In actual detection, quantitative detected data can be given to the surface profile of the aspheric surface optical element by only getting help from an ordinary auxiliary collective lens. Compared with the existing aspheric surface inspection method, a method using the device has better environmental suitability and very strong universality and can be suitable for detection requirements of optical aspheric surfaces with different batches and different parameters.

Description

technical field [0001] The invention relates to a device for measuring the surface profile of an aspheric optical element with a large dynamic range. The device can provide quantitative detection data on the surface profile of the aspheric optical element only by means of an ordinary auxiliary converging lens. Background technique [0002] With the development of precision optical processing technology, aspheric optical components have been widely used in various optical systems, such as various high-quality cameras, video cameras, optical measuring instruments and scanners, and even with our daily life. Closely related products (such as aspheric automotive lights). [0003] Aspherical optical elements refer to optical elements whose surface shape is determined by a high-order equation, and the radii of each point on the surface shape are different. Aspheric surfaces have many unique properties. Applying aspheric surfaces to optical systems can reduce the number of optical...

AI Technical Summary

Problems solved by technology

For example, the surface profile method belongs to the mechanical contact measurement. When the mechanical probe touches the surface of the optical element, it is easy to cause damage to itself and the optical element; the aberration-free point method is a common detection method for aspheric optical elements, but it is only applicable For secondary aspheric optical elements, and for different aspheric optical elements, the applicable detection optical path is also different, often requires a higher precision auxiliary spherical mirror; compensation interferometry is to design and manufacture a certain compensator to make the aspheric optical element The reflected wavefront of the reflective wave can be as close as possible to the spherical wave to realize the detection. Similarly, the compensator is designed correspondingly to the parameters of the aspheric optical element, and the error of the compensator itself usually cannot be eliminated in the detection.

The shearing method is a method of splitting beams to generate shearing interference between two related wavefronts to reflect error information. However, due to the limitation of device aperture, it is generally only used in small-aperture and small-relative-aperture aspheric optical elements. checking

Computational holography does not require the use of interference templates, but the holographic templates have a large amount of calculation, which requires high precision for the reset of the holographic templates, and one aspheric optical element corresponds to the production of a holographic template, so the versatility is not strong; in addition, there are Move the interferometer or aspheric optical element along the optical axis on the spherical interferometer, change the distance between them to generate a non-concentric beam, and match the different annulus of the measured aspheric optical element through reference spherical waves with different curvature radii area, so that the slope difference of the measured element relative to the reference wavefront is reduced to the allowable range of the interferometer, each annular sub-aperture area is measured by interferometry, and then spliced ​​and fitted to obtain the entire surface shape information, that is, the so-called annular sub-aperture area Aperture Stitching

This method can extend the existing spherical interferometer to the detection of aspheric optical elements, but it requires high precision of device adjustment

[0005] Based on the above introduction, it can be seen that various detection methods of aspheric optical components have their own limitations and the singleness of detection objects

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