Design of High Sensitivity and high FoM Refractive Index Biosensor Based on 2D-Photonic Crystal

This paper aims at proposing a new design based on the refractive index using 2D photonic crystals (PCs) for diagnosing basal cell carcinoma (BCC). This project consists of a square array of GaAs rods in SiO2. This structure has two inlet and outlet waveguides and a micro-cavity. Waveguides are employed to couple light to the cavity, and the cavity to inject analyte into it. Some PC rods were used to separate the cavity from the inlet and outlet waveguides. The results show that by injecting an analyte into the cavity and changing its refractive index, a shift occurs in the resonance wavelength of the transmission spectrum. The high sensitivity coefficient obtained for this sensor is 730 nm/RIU and its high Figure of Merit (FoM) is 11428. For numerical analysis of the transmission spectrum, Q-factor, and sensor sensitivity, the finite-difference time-domain (FDTD) method was used. High simplicity, sensitivity, FoM make it suitable for biosensing applications.