Simultaneous measurement of temperature and strain by using a wide-band fiber Bragg grating

A novel power-interrogated sensor that allows for the simultaneous measurement of temperature and strain is proposed and experimentally demonstrated. The sensor is based on the use of a linearly chirped fiber Bragg grating (FBG) with a broad (~10 nm) as well as slant reflection spectrum. Unlike most of the previous FBG-based sensors, the FBG proposed here is simultaneously used as both the sensing and the interrogating element. The measurement accuracies for the temperature and the strain are estimated to be ±2 °C in the range of 12-197 °C and ±24in με the range of 0-1270 με, respectively.