Three-branch optical fibre interferometer for simultaneous measurement of two physical measurands

Abstract

A three-branch all-fibre optic interferometer (3B-FOI) based on a Mach-Zehnder configuration is proposed. We have studied the feasibility of using it to measure two phase perturbations. Results are presented which show the linearity of the detection scheme. It is shown that the 3B-FOI can be used to separate the induced phase changes produced by two measurands acting simultaneously on a single sensing fibre.