Optical fiber laser sensor for refractive index measurement

Abstract

A refractive index (RI) sensor was proposed and demonstrated. The sensor head was manufactured by splicing a section of multimode fiber between two single-mode fiber segments (SMS). The SMS structure was used as a filter and inserted into an Erbium fiber ring to generate laser, which can improved the detection accuracy of the sensor. The sensor provides an excellent linear response. RI sensitivity of 84.489 nm/RIU has been achieved and the measurement range is from 1.345 to 1.386.