Characteristics of D-shaped photonic crystal fiber surface plasmon resonance sensors with different side-polished lengths

Sensing characteristics of D-shaped photonic crystal fiber surface plasmon resonance sensors are investigated in this paper. The finite element method is used to study the influences of side-polished depths and sensing layer thicknesses on our sensors. The results show that the sensitivity increases with the increase of the sensing layer thickness but decreases a little with the increase of the side-polished depth in a certain range. The influences of the side-polished lengths on our sensors are studied experimentally. It is revealed that a short side-polished length is conducive to improving the performance of our sensors. The highest sensitivity of our sensors is obtained to be 7381.0 nm/RIU in the refractive index environment of 1.40–1.42, when the side-polished length is controlled at 10 mm. The novel D-shaped photonic crystal fiber surface plasmon resonance sensors will bring new vitality to the application of biochemistry.