Interferometric studies on multi-mode step-index optical fibres

Abstract

Multiple-beam interference of the Fizeau type is used to investigate multi-mode step-index optical fibres. Two different types of multi-mode step-index optical fibres are studied interferometrically. The first has a plastic cladding and silica core (the problems of studying this type of fibre and how to overcome these problems are outlined). The second fibre is a multi-mode multi-step-index (quadruple-layer) optical fibre. This sample is used to test the accuracy of the method used for calculating the refractive index profile of the fibres.