Design and simulation of high sensitive photonic crystal waveguide sensor

Photonic crystal waveguide, formed by local line defect in a perfect periodic structure, is generally used for sensing. In this paper, we have proposed a very high sensitive photonic crystal waveguide (PCW) based sensor in silicon-on-insulator (SOI) material after optimisation of etch-depth of the circular holes up to a finite depth underneath the buried oxide layer. Properties of the sensor are analysed by 3-D finite difference time domain (FDTD) method. Output transmission and sensitivity of the proposed sensor is analysed by varying the defect radius and etch depth. Optimised structure shows an average value of sensitivity as 386 nm/RIU over a range of refractive index of 1.0 and 1.5.