Method for comprehensively measuring reflectivity

Abstract

The invention relates to a method for comprehensively measuring reflectivity, which comprises the following steps: dividing continuous incident laser beams into a reference beam and a detection beam, wherein the reference beam is focused on a photoelectric detector for direct detection and the detection beam is injected into an optical resonant cavity; using a cavity ring-down technology to measure an optical element with reflectivity more than 99%, respectively measuring a ring-down time tau 0 of an original optical resonant cavity output signal and a ring-down time tau 1 of the measured optical resonant cavity output signal after an optical element to be measured is added, and calculating the reflectivity R of the optical element to be measured; using the spectrophotometry to measure the reflectivity of the optical element to be measured when the R value is less than 99%; moving away an output cavity mirror; focusing detecting light reflected by a measuring mirror on the photoelectric detector for detecting while recording a light intensity signal ratio of the detection beam to the reference beam; and calibrating to further obtain the reflectivity R of the optical element to be measured. The device for measuring reflectivity can be used for measuring optical elements with any reflectivity and also can be used for realizing the high-resolution two-dimensional imaging of the reflectivity distribution of a large-aperture optical element.

Description

technical field [0001] The invention relates to a method for comprehensively measuring the reflectivity of optical elements, in particular to a method for measuring the reflectivity of arbitrary reflectivity optical elements and large-diameter optical elements. Background technique [0002] Spectrophotometry is the most commonly used method for measuring the transmittance and reflectance of optical components. In principle, as long as the reflected light energy flow E r and the incident light energy flow E 1 , the reflectivity is R=E r / E 1 . In actual measurement, the fluctuation of the output power of the laser light source is an important factor affecting the measurement results. For some high-reflectance optical components with a reflectivity of over 99.9%, the light intensity is very close when the optical component is not added to the optical path and when the optical component is added to the optical path. At this time, the slight fluctuation of the output power o...

AI Technical Summary

Problems solved by technology

[0004] The above-mentioned spectrophotometric device cannot accurately measure the reflectivity of optical elements with a reflectivity higher than 99.9%, and the high reflectivity measurement device based on optical cavity ring-down technology cannot measure the reflectivity of the optical element to be measured because its measurement accuracy is proportional to the reflectivity of the optical element to be measured. Accurately measure the reflectivity of optical components with reflectivity below 98%

At present, there is no report on the device that can realize the accurate measurement of arbitrary reflectance

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