Epoxy Resin Cap-Based Low-Finesse Fiber Fabry-Pérot Interferometer for Temperature Sensing

A low-finesse fiber Fabry-Pérot interferometer (FFPI) assisted by an epoxy resin (ER)-based has been proposed and experimentally demonstrated for temperature measurement. The cavity of the interferometer is a cap of ER at the end-face of the single-mode fiber. A well-defined interference spectrum is obtained with a clear extinction ratio, resulting from the optical phase difference between two light reflected at two surfaces of ER cap. Experimental results indicate that the proposed FFPI presents the high temperature sensitivity in the measurement range of 40 °C–160 °C. The proposed sensor has advantages of small size and high stability, and so on, making it a good candidate for temperature measurement.