Photonic Crystal Rectangular Hole Based Nanobeam Cavity Refractive Index Sensor

In this study, we propose the design of a one-dimensional photonic crystal rectangular hole based nanobeam cavity structure for refractive index sensing. The designed sensor structure consists of periodic air slots on a thin substrate which is made of a dielectric thermoplastic material. Here, three-dimensional finite-difference time-domain method is used to evaluate resonator and refractive index sensing characteristic of the designed sensor structure. The light localization in the cavity region is numerically investigated for various refractive index values at microwave wavelengths. The sensitivity of 5.739 mm/RIU is calculated for a liquid analyte with refractive index value at around 1.33. The possible experimental validation of numerical results can be demonstrated at microwave wavelengths by 3D-printing the designed sensor structure.