Refractive Index and Temperature Detection Using a SMS Interferometer integrated in an Erbium-Doped Fiber Ring Laser

Abstract

In this work, a dual parameter sensing of refractive index and temperature sensor based on an interferometric design integrating single-mode fiber (SMF), no-core multimode fiber (NCF), and single-mode fiber (SMF) was developed and experimentally validated. The SMS structure was used as a filter and incorporated into an erbium-doped fiber ring laser to enhance the sensor’s detection accuracy. Experimental results demonstrate that the sensor exhibits an excellent linear response in the refractive index detection, with a sensitivity of 96.639 nm/RIU over a measurement range from 1.346 to 1.406 and remarkable temperature sensitivity.