Reflective index sensors based on tilted fiber Bragg grating inscribed in the thin-core fiber

摘要

A compact optical fiber reflective index sensor is proposed and experimentally demonstrated. It is based on the tilted fiber Bragg grating (TFBG) inscribed in the thin-core fiber that is downstream spliced to the conventional single mode fiber (SMF). Thanks to the core dismatch between the SMF and the thin-core fiber, more cladding modes can be recoupled back into the SMF .The sensor can be used to detect the change of surroundings refractive index (SRI). Besides, the sensor can solve the problem of cross-sensitivity between SRI and temperature.