Analysis of a New High-Performed Terahertz Metamaterial Absorber for Refractive Index Sensor Applications

This paper reports on the design and analysis of a metamaterial perfect absorber-based terahertz refractive index sensor. The absorber material consists of a polytetrafluoroethylene (PTFE) substrate, with a gold resonator layer on top and a transmission-blocking ground layer deposited beneath the substrate. The primary simulation is performed using the Computer Simulation Technology (CST) software, which determines that the peak absorption occurs at a frequency of 0.74 THz and reaches a value of 99.95%. The outcome is diverse while employing the COMSOL Multiphysics software, although the outcome appears comparable. The outcomes are independent of different polarized waves such as Transverse Electric (TE), Transverse Magnetic (TM), or Transverse Electromagnetic (TEM) waves. The metamaterial absorber exhibits complete stability concerning THz waves' polarization and incident angle. This work also examines the analysis of the material's electric field (E), magnetic field (H), and surface current. The sensor setup of the absorber is depicted along with its performance parameters. The material possesses a quality factor (Q -factor) of 370, a sensitivity of 3.55 THz/RIU, and a figure of merit (FOM) of 1775 at a frequency of 0.74 THz. The performance is also evaluated in comparison to relevant literature. The developed metamaterial absorber has significant benefits and can be effectively utilized in refractive index sensing applications.