We examine the refractive index sensor ability of the terahertz surface plasmon modes supported by a planar plasmonic terahertz (THz) waveguide. The waveguide is comprised of one-dimensional array of periodically arranged subwavelength scale pyramidal corrugations resulting in a plasmonic metamaterials waveguide. The waveguide exhibits strong field confinement along with the corrugated pattern. We have analyzed the dispersion property and quality factor of the fundamental as well as higher-order modes of the waveguide. In order to examine sensor capability, we used analytes of different refractive indices and observed a corresponding frequency shift. We further analyze the sensitivity of all the modes for the given volume of analyte and compare their sensing performance. We have employed the semi-analytical model to understand the numerical observations. The proposed waveguide approach can potentially result in highly sensitive refractive index sensors at terahertz frequencies.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering