Anti-Resonant Reflecting Guidance in Silica Tube for High Temperature Sensing

A high temperature fiber sensor based on silica tube is proposed and experimentally demonstrated. The sensor consists of a short section of silica tube spliced between singlemode fibers. Due to the anti-resonant reflecting effect in the silica tube, the transmission spectrum of the structure exhibits periodic notches. When the sensor is exposed in increasing temperatures, the transmission notches shift toward longer wavelength. A temperature sensitivity of 20.31 pm/°C is obtained between room temperature and 1000 °C. The sensor structure is simple, compact with good spectrum repeatability, which can find applications in harsh environments.