Nanophotonic Sensor Based on Photonic Crystal Structure Using Negative Refraction for Effective Light Coupling

In this paper, using the 2-D finite-difference time-domain (FDTD) method, we study a novel biosensor based on collimation effects in photonic crystals (PCs) with negative refractive index. Coupling the collimated beam to a line of air holes (sensing region) filled with normal air, dry air, liquid, and gas is thoroughly investigated. It is shown that by an appropriate selection of design parameters, such as, the air cylinder radii and coupling distance, it is possible to achieve ultracompact sensing platforms. The collimation effect features channel allocation in nanosystems and high sensitivity for biomolecules sensing applications.