High Sensitivity Refractive Index Sensor Based on Indium Antimonide Terahertz Plasmonic Ring Resonator

A high sensitivity refractive index semiconductor-insulator-semiconductor (SIS) waveguide with a ring resonator sensor at THz frequency is proposed. The topological study of the proposed filter is numerically simulated using the finite element method. A maximum sensitivity of 0.509 THz/ Refractive index unit (RIU) is obtained by filling the air-filled ring resonator cavity with different refractive index materials. Besides that, the transmission characteristics are studied by varying the structural dimensions and observed that the system can be treated as a frequency selective device. The device gets modified by incorporating another concentric ring inside the single ring. From the transmission characteristics, the multiple modes of the concentric dual ring are studied, and concluded that the even TM1 mode shows a better response towards frequency tuning.

Automated summary

A high sensitivity refractive index SIS waveguide with a ring resonator sensor at THz frequency is proposed in this study. The topological structure of the proposed filter is numerically simulated using the finite element method. By filling the air-filled ring resonator cavity with different refractive index materials, a maximum sensitivity of 0.509 THz/RIU is achieved. The transmission characteristics are studied by varying the structural dimensions, and it is observed that the system can be treated as a frequency selective device.