The optical refractometry using transport-of-intensity equation

Abstract

Abstract A development of a method for measuring the refractive index of optical media based on the transport-of-intensity equation (TIE) is proposed. The method requires only a complementary metal-oxide semiconductor (CMOS) camera, which registers intensity distributions in several planes. The obtained intensity distributions are used to solve the TIE, known as a non-interferometric and deterministic method of measuring the phase of a light wave. Simple physical relations connecting the phase of the light wave that has passed through an optical medium and its refractive index allows to determine the latter. The results of the experiment confirm the applicability of the proposed method to the problems of optical refractometry.