Refractive index and strain sensor made of S-tapered photonic crystal fiber

An experimental investigation on an S-tapered photonic crystal fiber interferometer is presented in this paper. The sensor exhibits highly surrounding refractive index sensitive, which is 4.7 x 10(-3) RIU (refractive index unit) in 1.33-1.39 and 1.45 x 10(-3) RIU in 1.39-1.44 commensurable with general sensors. Attribute to the S-shape's distortion, red shifts are measured in axial strain test. In addition, insensitivity (4.3 pm/degrees C) in low temperature and sensitivity (22.4 pm/degrees C) in high temperature are confirmed by experiments. These properties combined with a simple fabrication process and a durable structure.