High sensitivity terahertz sensor based on double-split hexagonal ring metamaterial

Terahertz (THz) metamaterial biosensors have received extensive attention in the biological field due to their label-free, real-time detection characteristics. In this study, a metamaterial structure, and its application in refractive index sensing is presented. The unit cell of the sensor is composed of a double-split hexagonal metal ring structure deposited on a quartz substrate. A parametric study was performed to evaluate the sensitivity change with different dimensions of the structure. The results show that the sensor can excite dipole resonance, and the corresponding absorption feature centers at 2.338 THz. The sensitivity of the refractive index sensor was evaluated in the simulation, and was determined to be 430 GHz/RIU (Refractive Index Unit) with a 10
$\upmu \mathrm{m}$
-thick analyte layer. The proposed sensing structure with high sensitivity is simultaneously easy to fabricate and has a great potential in bio-sensing.