In-line single-mode fiber interferometers based on peanut-shape fiber structure

Abstract

A novel peanut-shape fiber structure which can realize the coupling and re-coupling between the fiber core mode and the cladding modes is proposed in this paper. Based on the peanut-shape structure, two kinds of simple and low-cost interferometers are fabricated in single-mode fiber (SMF). Experimental results show that the temperature sensitivities of the Mach-Zehnder and Michelson interferometers were ~46.8pm/°C and ~0.096 nm/°C, respectively. In particular, the Michelson interferometer could be heated up to 900°C, which is suitable for the high temperature sensing applications.