Measurement of high reflectances by use of multi-paths optical cavity

Abstract

We propose here an experimental set-up allowing a precise measurement of mirror reflectances close to unity. The experimental arrangement is easy to adjust, although it requires the use of multi-paths optical cavity. The method can be applied to spherical mirrors as well as flat ones. The accuracy is up to 5.10−4. Results of measurements for visible and infrared spectral ranges are presented.