A Dual-Parameter Sensor Using a Long-Period Grating Concatenated With Polarization Maintaining Fiber in Sagnac Loop

In this paper, a novel dual-parameter measurement scheme using a long-period grating (LPG) concatenated with polarization maintaining fiber (PMF) in a Sagnac loop was proposed and experimentally demonstrated to measure temperature and refractive index (RI) simultaneously. There are two types of dips in the output spectrum of the proposed sensor, which are formed by the LPG and Sagnac loop. Compare...