High-reflectivity scanning and measuring multi-wavelength integrated method of large-aperture reflection optical element

Abstract

The invention discloses a high-reflectivity scanning and measuring multi-wavelength integrated method of a large-aperture reflection optical element, and the method comprises the steps of: injecting the ith laser (i is equal to 1,... N, N is larger than 2) into the ith stable initial optical resonant cavity formed by high reflectors according to a cavity-ring-down technical principle, recording the cavity-ring-down signal, and fitting through a single exponential function to obtain the ring-down time tau 0i of the ith initial optical resonant cavity at the ith beam of laser wavelengths; meanwhile, adding the large-aperture reflection optical element to be measured in the initial optical resonant cavity through angle to form a stable ith testing optical resonant cavity, arranging the large-aperture reflection optical element to be measured on a two-dimensional displacement platform, recording the cavity-ring-down signal, and fitting through the single exponential function to obtain the ring-down time tau i of the ith testing optical resonant cavity at the ith beam of laser wavelengths, obtaining the reflectivity Ri of a high reflector to be measured at the ith beam of laser wavelengths through the tau 0i and the tau i, and realizing reflectivity two-dimensional imaging measurement on the large-aperture reflection optical element to be measured by moving the two-dimensional displacement platform.

Description

technical field [0001] The invention relates to a method for measuring the reflectivity of a high reflection mirror, in particular to a multi-wavelength integration method for scanning and imaging measurement of high reflectivity of a large-diameter reflective optical element. Background technique [0002] In recent years, with the development of high-power laser technology and its expanding application range, large-aperture reflective optical elements (usually greater than 0.3m) have been used more and more widely in large-scale laser systems. Large-aperture reflective optical elements The reflectivity and uniformity of the laser system are closely related to the normal operation of the laser system, so that the uniformity of the film layer has become an indispensable performance index for large-aperture optical films. For large-aperture reflective optical components, only by quantitatively measuring the reflectivity at different positions of the optical film can it be poss...

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Problems solved by technology

Chinese Patent Application No. 98114152.8 "A Method for Measuring High Reflectivity of High Mirrors", Chinese Patent Application No. 200610011254.9 "A Method of Measuring High Reflectivity of Mirrors" and Chinese Patent Application No. 200710098755.X The invention patent "High reflectivity measurement method based on semiconductor self-mixing effect" uses optical cavity ring-down technology to achieve high reflectivity measurement, but it is only for single-point reflectivity measurement, and does not give a reflectivity uniformity measurement method

Chinese Patent Application No. 201010608932.6 is an invention patent "a comprehensive reflectance measurement method" and a large-diameter element reflectivity scanning measurement system proposed by Yi Hengyu et al. (Yi Hengyu, Peng Yong, Hu Xiaoyang; mirror scanning of large-diameter element reflectivity Precision measurement system, "Strong Laser and Particle Beam", 2005, 17: 1601), although the reflectance uniformity measurement method is given, but its devices are only suitable for a single band reflectance measurement

[0004] The above measurement methods and devices are all designed for a certain wavelength band. One set of devices cannot measure the reflectivity of multiple reflective optical components in different wavelength bands, which means that multiple sets of independent test device

For the imaging scanning measurement of the reflectivity of large-aperture reflective optical components, a two-dimensional displacement platform with high precision, high spatial resolution, and large moving range is the core component. The cost of the two-dimensional displacement platform is hundreds of thousands or even millions (depending on the optical Component size), accounting for more than 80%~90% of the total cost of the measuring device, if such a two-dimensional displacement platform is used in each band reflectance measuring device, the cost will be huge

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