Method and device for detecting refractive index of optical element

Abstract

The invention provides a non-destructive and highly-precise refractivity measuring method for miniature optical elements and a detection device thereof. The detection method comprises the following steps: (1) lights emitted by a light source go through a collimating lens and a light gap, then the lights is parallelly incident on a first sample cell and a second sample cell; then the lights go through a convergent lens and are converged on a cylindrical mirror, and two interference fringes vertically arranged can be watched from an observation pipe behind the cylindrical mirror; (2) an optical element to be measured is put into the first sample cell, and the upper interference fringe moves relative to the lower interference fringe; (3) calculating the interference grade through watching the displacement situation of the interference fringes, and finally obtaining the refractivity value of the optical element through formula calculation. The invention utilizes a Rayleigh interferometer, establishes a novel measuring method, and utilizes the two beam interference method's characteristics of high precision, simple structure, and user-friendliness so as to achieve the non-destructive and highly-precise measurement on refractivity of miniature or deformed optical elements.

Description

technical field [0001] The invention relates to a detection method for the refractive index of an optical element, in particular to a non-destructive detection method and a detection device for a small optical element. Background technique [0002] With the development of the optical industry, the requirements for various small optical components are not only large in quantity, but also high in quality. The refractive index parameters of optical components are the basis of optical design. Only by accurately mastering the reliable data of the refractive index of optical materials can high-quality design work be completed according to requirements. For the research and manufacture of optical element materials, determining the refractive index performance index of the optical element material under study is an important basic content, the technical basis for material evaluation, and the reference basis for production finalization. The accurate determination of the rate is the ...

AI Technical Summary

Problems solved by technology

Both of the first two methods require the sample to be tested to be a block sample larger than a few millimeters. For small optical components, it is necessary to destroy it and make a block sample for testing. It is often difficult or impossible to prepare samples, especially After the sample is prepared by melting, the refractive index of the material will change. If it is not cooled quickly, it will be very easy to crystallize, and the sample will be devitrified and the refractive index cannot be measured at all. The measured refractive index does not represent the optical quality. The refractive index of the component itself

However, the oil immersion method is limited by the measurement range of the Abbe instrument and the influence of personnel's experience and judgment, so the measurement range for the refractive index of small optical components is very limited.

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