High sensitivity liquid analyte filled photonic crystal fiber refractive index sensor covered by symmetrical metalnano-films based on surface plasmon resonance

Abstract A high sensitivity of photonic crystal fiber (PCF) with a tunableliquid core refractive index sensor based on surface plasmon resonance (SPR) induced bythe symmetric metal films is proposed in this paper. The SPR excitation materials are chose as gold and silver. The transmission characteristics and sensing performance of the SPR-PCF sensor with different geometrical parameters were analyzed by using finite element method (FEM) and Maxwell equation. The final results show that when thediameter of the central hole is 1.6µm and the thickness of the gold film is 40nm, the SPR occurs at the wavelength of 1400nm, and the confinement loss can reach 17398dB/m. The average sensitivity of the SPR-PCFsensor can reach 7200nm/RIU, and the linear fitting constant is R2=0.99959, which is expected to have important applications in the direction of liquid refractive index detection.