Fiber optic SPR sensor for refractive index and temperature measurement based on MMF-FBG-MMF structure

Fiber optic SPR (Surface Plasmon Resonance) sensor based on MMF-FBG-MMF (Multi-mode Fiber–Fiber Bragg Grating–Multi-mode Fiber) structure has been proposed and applied to dual-parameter measurement– liquid refractive index and temperature. The fabrication method of this proposed sensor is simpler than other kinds of fiber optic SPR sensors. The basic sensing principle of fiber optic SPR sensors has been provided and the dual-parameter measurement system has been set up. The changes of NaCl resolution refractive index and temperature have been detected and analyzed. The refractive index sensitivity of the proposed sensor has reached 2556.8 nm/RIU, and the temperature sensitivity has been improved to 172 pm/°C.