Design of a surface plasmon resonance refractive index sensor with high sensitivity

This paper presents a highly sensitive photonic crystal fiber (PCF) refractive index sensor based on the surface plasmon resonance (SPR) effect operating in the telecommunication wavelengths. Gold is used as the plasmonic material due to its chemical stability and titanium dioxide (TiO2) is used to shift the resonance wavelength in the telecommunication bands. Both materials are deposited sequentially on the PCF surface, which is comparatively easy to fabricate. Numerical investigations show that the proposed sensor exhibits very high wavelength sensitivity of 10,800 nm/RIU and amplitude sensitivity of 514 RIU−1 in the sensing range between 1.46 and 1.48. Moreover, it exhibits maximum sensor resolution of 9.25×10−6 RIU and high linearity over a wide sensing range. The proposed sensor can be practically realized due to its simple and straightforward structure.