Measurement of the refractive index using a goniometric system

Abstract

The article proposes a method for measuring the refractive index using a goniometric system that does not require measuring the prism angle, which simplifies the measurement process compared to the widely used methods of minimum deviation and autocollimation. This method can be used to measure the refractive index of samples in the form of triangular prisms in the visible, ultraviolet and infrared ranges. To implement the method, a goniometric system was used. To obtain the reflection of the refracted beam, a fixed mirror was used, and the refractive index of the prism material was calculated from the solution of a system of equations. The results of an experimental study of a triangular prism made of optical glass N-BK7 using the proposed method and their comparison with the data obtained on the State Primary Standard of the Refractive Index Unit GET 138-2021 are presented. Keywords: goniometer, refractive index, prism method.