High sensitivity D-shaped hole fiber temperature sensor based on surface plasmon resonance with liquid filling

A high sensitivity D-shaped hole double-cladding fiber temperature sensor based on surface plasmon resonance (SPR) is designed and investigated by a full-vector finite element method. Within the D-shaped hole double-cladding fiber, the hollow D-section is coated with gold film and then injected in a high thermo-optic coefficient liquid to realize the high temperature sensitivity for the fiber SPR temperature sensor. The numerical simulation results show that the peaking loss of the D-shaped hole double-cladding fiber SPR is hugely influenced by the distance between the D-shaped hole and fiber core and by the thickness of the gold film, but the temperature sensitivity is almost insensitive to the above parameters. When the thermo-optic coefficient is -2.8 x 10(-4)/degrees C, the thickness of the gold film is 47 nm, and the distance between the D-shaped hole and fiber core is 5 mu m, the temperature sensitivity of the D-shaped hole fiber SPR sensor can reach to -3.635 nm/degrees C. (C) 2017 Chinese Laser Press