improving the performance of the ri sensor based on a disk-shaped graphene absorber using pyramidal air holes in the dielectric layer

This manuscript introduces a highly sensitive refractive index sensor that utilizes a disk-shaped graphene absorber. this design takes advantage of graphene's exceptional properties and integrates pyramid-shaped air holes within the dielectric layer. the sensor operates in the terahertz (thz), with a specific focus on improving sensitivity and overall performance. graphene's high electrical conductivity and tunable properties make it an ideal material for thz absorption, enabling precise detection of refractive index changes the proposed structure comprises a graphene pattern on the top layer, a sio2 as dielectric in the middle layer, and a gold reflective in the bottom layer. through full-wave simulation and transmission line modeling, the sensor's performance is validated, showing a remarkable rate of absorption of 99.99% at 4.26 thz. further enhancement is achieved by introducing pyramidal air holes in the dielectric layer, significantly improving the sensor's quality factor and sensitivity. the quality factor of the sensor is improved from 14 to 23 by adding pyramidal air holes in the substrate layer. the structure was full-wave simulated using software cst with the fdtd solution method, and the transmission line method was done with the matlab software. the results suggest that the planned sensor serves as a highly suitable candidate for early disease detection, including cancer and influenza, with potential applications in the medical industry.