Sensitivity analysis of a photonic crystal waveguide for refraction index sensing

Photonic crystal (PC) sensors have attracted much attention because of their inherent compactness, high sensitivity and biocompatibility traits. In this paper, we analyze the design of highly sensitive infiltrated liquid sensors based on a two-dimensional PC slab waveguide formed by increasing the radii of air holes localized on each side of the line defect and filling with homogeneous de-ionized water (n(c) = 1.33). The transmission spectrum of the sensor has been obtained by the finite-difference time domain method, and it has been observed that a 270 nm wavelength position of the upper band edge shift was observed corresponding to a sensitivity of more than 818 nm per refractive index unit. The simulation results on the sensitive PC structure show that the optical properties of PCs can be used to design sensing devices characterized by a high degree of compactness and good resolution.