Simultaneous temperature and refractive index sensor based on a tilted fibre Bragg grating

摘要

Optical device based on a tilted fibre Bragg grating (TFBG) to perform simultaneous measurement of refractive index (RI) and temperature is proposed. Using two different demodulating techniques, namely monitoring the core mode wavelength and the area of the transmission spectrum, it is possible to measure, separately, temperature and RI, respectively. The proposed method uses a grating, which does not require a reduced diameter, and a single measurement equipment. Measurements with resolution up to 5.7 × 10~(-4) and 0.5 °C were achieved, for RI and temperature, respectively. Theoretically, the resolution of RI measurements can go as bellow as 2 × 10~(-5).