Biosensing With Asymmetric High Refractive Index Contrast Gratings

We propose a novel label-free optical biosensor configuration based on a spectral refractive index sensing method by utilizing asymmetric high index contrast dielectric gratings. The characterization and performance evaluation of the designed biosensor are carried out by using 2D and 3D finite-difference time-domain methods. The designed sensor is illuminated in-plane with transverse-electric polarized light wave. The salient properties of the device are compactness, having a simple measurement technique, easy excitation scenario, operating labelfree, and possessing high sensitivity value reaching up to a level of 450 nm/RIU. The proposed sensor configuration may bring new impetus to the field of alternative biochemical sensing approaches.