Temperature effects on surface plasmon resonance sensor based on side-polished D-shaped photonic crystal fiber

Abstract

A comprehensive temperature Drude theoretical mode has been established to study the temperature effects on the side-polished photonic crystal fiber (PCF) surface plasmon resonance (SPR) sensor. In the theoretical model, the temperature dependence coefficients of fiber material refractive index (RI), sensing film thickness and metal-dielectric function have been considered. The finite element method (FEM) is used to study the influence of side-polished depth, metal thickness, air hole size, and lattice constant on sensing performance with findings as following: (1) the dependence of the resonance wavelength on temperature is almost unaffected by duty ratio or lattice pitch of PCF; (2) the peak loss of the PCF SPR sensor with small lattice pitch (or increased duty ratio) is more sensitive to temperature variation; (3) for the sensor working in intensity interrogation mode, linear relationships can be found between the peak loss versus the RI and temperature. Moreover, we fabricate a side-polished D-shaped PCF SPR sensor by a wheel polishing setup, and the experimental results display a good agreement with the theoretical investigations. This study offers a detailed way to analyze the temperature effects on the sensor, and may lead to the better design and the data-progress improvement for D-shaped PCF SPR sensor.