High-sensitivity temperature sensor based on microstructured fiber outside coated with gold and PDMS films

Abstract A high-sensitivity temperature sensor based on microstructured fiber (MSF) outside coated with gold and Polydimethylsiloxane (PDMS) films has been presented in this paper. The gold film is coated outside the fiber cladding, wich is used to excite the surface plasmon resonance (SPR), and PDMS is a kind of substance with high thermo-optical coefficient and easy to be cured, the temperature response has been effectively improved by depositing PDMS film outside the gold film. 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 9.287nm/℃ in the range of -20℃-40℃. Moreover, compared with other designs, the fully coated structure on the outside of MSF enables temperature-sensitive medium to be in direct contact with the environment, which reduces the difficulty of internal coating and filling in the air-holes of MSF. The optimized process of structure in this study provides an effective method, and the temperature sensor based on MSF has good application prospects in the fields such as medical treatment, biochemical detection, and intelligent monitoring.