Simultaneous Measurement of Temperature and Refractive Index Using a Fiber Bragg Grating and a Multimode Fiber
We introduce an all-fiber sensor capable of simultaneous measurement of temperature and refractive index (RI). The sensor system consists of a single mode fiber Bragg grating (FBG) and a single-mode-multimode-single-mode (SMS) structure which serves as a Mach-Zehnder interferometer (MZI), and the multimode fiber (MMF) is etched by hydrofluoric acid solution. The experimental results demonstrate that the temperature sensitivities of FBG and MZI are 0.016nm/°C and 0.093nm/°C, respectively, and the RI sensitivity of MZI achieves 226.25nm/RIU. The interesting properties of the sensor include compact size, high sensitivity and good operation linearity.
Z. R. Tong et al., "Simultaneous Measurement of Temperature and Refractive Index Using a Fiber Bragg Grating and a Multimode Fiber", Applied Mechanics and Materials, Vols. 130-134, pp. 4053-4056, 2012