Light intensity correcting method for arranging annular light intensity monitoring section around interferogram

Abstract

The invention relates to a light intensity correction method by cutting out a circular light intensity monitoring area on the outer ring of the interferogram, which comprises the following steps: 1, adding a the aperture diaphragm of the tested piece, and converting the outermost ring shaped part into light intensity monitoring area directly; 2, recording the light intensity in the light intensity monitoring area while recording the interferogram by the only image detector in the system; 3, processing the image to obtain light intensity correction coefficient, processing the light intensity in the light intensity monitoring area before processing the sequential interferogram to abstract the light intensity correction coefficient; 4, correcting the light intensity of the interferogram by the light intensity correction coefficient. the invention can accomplish the monitoring light detection while recording interferogram only by adding the aperture diaphragm of the tested piece into classic interferometer, neither change the light path mode nor adds complex component or sub light path, and has a very simple hardware system; it maintains the tested aperture furthest while acquiring enough light intensity correction information by adopting the outer ring light intensity monitoring area.

Description

technical field [0001] The invention relates to laser interferometry technology, the purpose of which is to simply, accurately and real-timely correct the light intensity change of the interferogram caused by laser light intensity drift, etc. . Background technique [0002] Laser interferometry is a photoelectric measurement method that uses the coherence of laser light to process the information reflected by the phase change. Since light is a high-frequency electromagnetic wave, it is difficult to directly observe its phase change, so it is much easier to observe it by using interference technology to convert the phase difference into the change of light intensity. Usually, by using the interference between the reference light of the reference reflective surface and the measuring light reflected by the measured object, the distance of the measured object and the surface shape and other parameters can be measured non-contact, and the measurement accuracy is generally on the...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is how to directly extract the sampling light from the interferogram acquisition optical path, and accurately correct the influence of laser light intensity drift and other factors on the interferogram light intensity without adding complex optical paths or detectors, so as to improve the interference measurement accuracy

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