Terahertz spoof plasmonic coaxial microcavity
Date of Issue2014
School of Physical and Mathematical Sciences
We theoretically demonstrate a subwavelength spoof surface-plasmon–polariton (SPP) microcavity on a planar metallic surface working at the terahertz regime with a high-quality factor and ultra-small mode volume. The microcavity is based on plasmonic and metamaterial notions, and it consists of an easy-to-manufacture circular aperture and a bell-shaped metallic core. It is shown that such a structure can sustain SPP eigenmodes whose fields are tightly trapped within the microcavity. Using the proposed structure, a total Q factor of 1000 (including losses from metals at low temperatures) and subwavelength mode volume of 0.00018(λ/2)3 can be achieved in the THz range for the fundamental surface-plasmonic eigenmode at room temperature. Moreover, the key figures of merit such as resonance frequency can be flexibly tuned by modifying the geometry of the microcavity, making it attractive for broad applications in filters, light sources, energy storage, and on-chip optical communications.
© 2014 Optical Society of America. This paper was published in Applied Optics and is made available as an electronic reprint (preprint) with permission of Optical Society of America. The paper can be found at the following official DOI: http://dx.doi.org/10.1364/AO.53.001118. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.