Interferometric method to measure light-transparent materials Available to Purchase

The paper introduces a modified Michelson’s interferometer operating with a quarter of wavelength precision and an octave of wavelength accuracy. The interferometer has a wide field of applications. We focus the present work on the measure of the thickness and refractive index homogeneity of high quality light-transparent optical materials. Majority of current methods already adopted to perform the same measurements depends on wave front distortion due to the surface irregularities of the sample under test thus these methods suffer of a systematic error. Infect measurement results may depend on the optical surface irregularities and the optical material local non-homogeneity as well, thus giving misleading interpretations. The proposed method enables to discriminate between measurements affected by surface irregularities and medium homogeneity. The paper describes the mathematical model of the modified Michelson’s interferometer and the measurement procedure.