PANDA Fiber Sagnac Interferometer for Temperature Sensor Application

Abstract

Fiber Sagnac loop mirror has great potential for use in various application such as multi-wavelength laser source, strain and temperature sensors. This paper demonstrates an optical fiber temperature sensor based on two lengths of PANDA polarization maintaining fibers (PMFs) in a fiber Sagnac interferometer. The temperature sensing is based on the change of spectral spacing of the generated optical comb with the temperature difference between two PMFs. The performance of the system was characterized numerically and experimentally by measuring the spectral spacing when raising the temperature of one of the PMFs. A high temperature sensitivity up to 0.36 nm/°C is obtained, with detuning range of 43 nm. This makes it a good candidate for various in-field sensing application.