Fiber-optical interferometer

Abstract

A rectangular optical waveguide of homogeneous refractive index (dimensions 0.10×0.14×100 mm³) is designed to provide double self‐imaging of either end face upon the opposite one. We show how to use this guide as a fiber‐optical beamsplitter and, with the addition of a mirror, as a two‐beam interferometer. The operation of the interferometer demonstrates the mutual coherence of the split images. Applications are possible for in‐line fiber‐optical interferometric devices.