High-precision position detection device and method

Abstract

The invention discloses a high-precision position detection device and a high-precision position detection method and belongs to the field of optical detection. The device comprises a short coherent light source, a collimating lens, a polarizer, a 1 / 2 wave plate, an optical splitter, a holophote a coupling lens, an end reflection fiber beam splitter, a focusing lens, a polarization analyzer, a sensor, two 1 / 4 wave plates and a multifocal lens; and the parts form a reference light path and a measurement light path. The optical path difference of different branches in the reference light path is fixed and different; and if assuming a test range is L and the reference light path comprises n branches, in order to test the optical surface space in the length of L, a movable lens is only required to move a distance of L / n, and the positions of different optical surfaces in the L range of a tested system can be accurately known by analyzing the position of the movable lens and the central position of interference fringe. The detection device has the advantages of wide detection range, small moving range of the movable lens, simple structure and high measuring accuracy.

Description

technical field [0001] The invention relates to the field of optical detection, in particular to a high-precision position detection device and method using light for detection. Background technique [0002] In a complex and high-precision optical system, it is necessary to test the distance between the assembled optical lenses. Since they have been assembled, they cannot be tested by mechanical means, and can only be checked in a non-contact way. A more suitable This application is carried out using the short coherent light source method, see the SPIE document "Contact-free on-axis metrology for the fabrication and testing of complex optical systems", the method given in this document uses Michelson's interferometer structure principle, through The method of moving the position of the movable lens in the reference arm to match the measured optical surface, and to test the position of different optical surfaces in the optical system. [0003] figure 1 The principle structu...

AI Technical Summary

Problems solved by technology

[0004] In this kind of detection equipment, the moving range of the movable mirror is consistent with the maximum working distance of the optical system, so when the distance between the optical system is large, the moving and detection range of the movable mirror also needs to be expanded accordingly, and it is necessary to work in a large range It is very difficult to achieve high-precision detection within a large area, and at the same time, large-scale movement increases the size of the equipment, reduces the reliability of the equipment, and makes the cost of the entire equipment increase sharply

Images