High-sensitivity temperature sensor based on photonic crystal fiber fully coated with gold and PDMS films.

Abstract This paper presented a high-sensitivity temperature sensor based on photonic crystal fiber fully coated with gold and PDMS films. For the convenience of production, gold film is coated outside the fiber cladding, and it is used to excite the surface plasmon resonance (SPR) effect. In addition, the temperature response has been effectively improved by depositing poly-dimethylsiloxane (PDMS) layer outside the gold film. This fully coated structure on the outside of PCF enables temperature-sensitive medium to be in direct contact with the environment, which reduces the difficulty of internal coating and filling. The influences of the parameters on the sensing characteristics are investigated by using the finite element method (FEM). Simulation results show that the average temperature sensitivity is up to 9.287 nm/℃ in the range of -20℃-40℃. Moreover, compared with other designs, the optimized process of structure in this study provides an effective method, which shows a wide application prospect to overcome the difficulty of filling liquid in the air holes.