Nonspherical absolute measuring system based on multiwave front lens compensator

Abstract

The invention relates to a nonspherical absolute measuring system based on a multiwave front lens compensator, which comprises a phase shifting interferometer, a standard lens, a multiwave front lens compensator, an electric control adjusting device and a driver thereof, a measured nonspherical optical element, a six-dimensional adjusting frame, an electric control translation platform and a drive thereof as well as a computer control and date processing system, wherein the multiwave front lens compensator comprises a plurality of optical elements or element groups. The invention realizes error separation by a plurality of interferometry for improving the surface shape detecting precision of the nonspherical optical element and has certain flexible measuring range and larger application value.

Description

technical field [0001] The invention relates to an aspheric surface absolute measurement system and a measurement method, which belong to the technical field of advanced optical manufacturing and detection. technical background [0002] The manufacture of high-precision optical components requires corresponding detection technology, and high-precision surface shape detection technology still faces great challenges. Digital phase-shift interferometer is the mainstream equipment for surface shape detection at present. The basic principle of interferometry is that the test wavefront carrying the surface error information of the optical element under test interferes with the reference wavefront, and then the interferogram is processed to calculate the phase value reflecting the measurement error information. As an ideal measurement "ruler" for relative measurement, the surface shape detection accuracy of the interferometer is mainly affected by the accuracy of the reference wav...

AI Technical Summary

Problems solved by technology

The main disadvantage of the three-position method is that the "cat's eye" is used to measure the position, and the test wavefront will reverse the optical path at this position, which will not meet the common optical path condition; in addition, the cat's eye position is not sensitive to adjustment errors, and its adjustment errors will lead to errors in the data processing process. Incorrect coordinate matching, resulting in inaccurate calculation results

The main disadvantage of this method is that the lithography structure error of the dual-wavefront computed hologram has different effects on the detection results when tested at two different positions in the optical axis direction.

[0005] In summary, the absolute measurement method is an effective method to improve the accuracy of surface shape interference detection. The spherical absolute measurement method is widely used, and the measurement process and data processing of the aspheric absolute measurement method are more complicated.

Images