Intracavity Laser Spectroscopy of Waveguide Structures

Abstract

A new technique of intracavity waveguide spectroscopy for investigating planar waveguide was proposed. It’s based on recording and processing angular spectrum of a light beam reflected from a prism coupler in case of exciting a guided mode in thin-film structure by the intracavity radiation of low-gain laser using a parallelepiped coupling prism in which the intracavity radiation enters the input faces of the prism at the Brewster angles and undergoes double internal reflection in the prism. It was demonstrated that the excitation of guided modes can be performed at the weak coupling. It was shown that the proposed technique can be used for measuring the optical parameters of low-loss planar waveguides.