On the design of subwavelength waveguiding structures for terahertz Applications

Closing the THz gap would lead to a tremendous of advancement in a wide range of applications such as biomedical imaging, security, and material inspection. The gap refers to the lack of devices for the manipulation of THz radiation as compared to its microwave and optical counterparts. Plasmonic devices based on semiconductors rather than metals allow the realization of efficient and small scale THz devices by utilizing the unique properties of plasmon oscillations. In this paper, we investigate the performance of an InSb-SiO₂-InSb structure for THz waveguiding. We study the propagation length and the skin depth of the symmetric and antisymmetric transverse magnetic modes of these waveguides. We use numerical techniques to solve for the dispersion relation and derive the propagation length and the skin depth as a function of frequency.