Liquid Refractive Index Sensor Based On A Polarization-Maintaining Fiber Loop Mirror

A liquid refractive index sensor based on a fiber loop mirror (FLM) combined with an etched polarization maintaining fiber (PMF) is proposed. As the etched section of the PMF is immersed in liquid with different refractive indices, the interference spectrum of the FLM presents high sensitivity to the surrounding-medium refractive index. High sensitivity of 25.29 nm/refractive index unit (RIU) and resolution of 7.91 x 10(-4) RIU are achieved for the proposed refractive index sensor. This sensor is also capable of simultaneous measurement of refractive index and temperature.