Device for measuring surface shape of high-reflection mirror

Abstract

The invention discloses a device for measuring the surface shape of a high-reflection mirror. The device comprises a light source, a beam splitter, a collimator, a standard lens and a CCD imaging system. The front surface of the standard lens is plated with a light splitting film, a light beam emitted by the light source passes through the beam splitter and then is converted into parallel light bythe collimator, when the parallel incident light Io passes through the standard lens, part of the light is emitted is reflected and returned by the standard lens plated with the light splitting film,the other part of the light passes through the standard lens to arrive at the surface of the measured lens and is reflected by the surface of the measured lens, the light IR reflected and returned bythe standard lens plated with the light splitting film and light It reflected by the surface of the measured lens after passing through the standard lens form interference light and return the interference light to the beam splitter, the interference the light enters the CCD imaging system after being reflected by the beam splitter, and the intensity ratio It / IR of the two paths of coherent lightis 0.2-1.

Description

technical field [0001] The invention relates to a measuring device for the surface shape of a highly reflective mirror, which belongs to the technical field of imaging measurement. Background technique [0002] The problem encountered when measuring the surface shape of a high-reflection mirror with an ordinary flat standard mirror: when the incident light IO passes through the standard surface of the standard mirror, the reflected light IR is only 4% of the incident light IO, and the reflected light IR is only 4% of the incident light IO after passing through the standard mirror. Light It is 18~92% of incident light 10, and the intensity difference of two beams of reflected light is too big It ≥ 5IR like this, causes interference fringe very unclear (as Figure 4 shown), and cannot be fully analyzed, the results of such analysis are very inaccurate. Aiming at this problem, the solution currently adopted in the market is to add a filter in front of the standard lens. Althoug...

AI Technical Summary

Problems solved by technology

[0002] The problem encountered when measuring the surface shape of a high-reflection mirror with an ordinary flat standard mirror: when the incident light IO passes through the standard surface of the standard mirror, the reflected light IR is only 4% of the incident light IO, and the reflected light IR is only 4% of the incident light IO after passing through the standard mirror. Light It is 18~92% of incident light 10, and the intensity difference of two beams of reflected light is too big It ≥ 5IR like this, causes interference fringe very unclear (as Figure 4 shown), and cannot be fully analyzed, the results of such analysis are very inaccurate

Aiming at this problem, the solution currently adopted in the market is to add a filter in front of the standard lens. Although this method can clearly reflect the interference fringes, there will be lines of the filter on the entire interference surface (such as Figure 5 shown), so that the surface accuracy of the actual measured lens surface is affected by the filter

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