title: Distributed gain in plasmonic reflectors and its use for terahertz generation.
abstract: Semiconductor plasmons have potential for terahertz generation. Because practical device formats may be quasi-optical, we studied theoretically distributed plasmonic reflectors that comprise multiple interfaces between cascaded two-dimensional electron channels. Employing a mode-matching technique, we show that transmission through and reflection from a single interface depend on the magnitude and direction of a dc current flowing in the channels. As a result, plasmons can be amplified at an interface, and the cumulative effect of multiple interfaces increases the total gain, leading to plasmonic reflection coefficients exceeding unity. Reversing the current direction in a distributed reflector, however, has the opposite effect of plasmonic deamplification. Consequently, we propose structurally asymmetric resonators comprising two different distributed reflectors and predict that they are capable of terahertz oscillations at low threshold currents.
authors.affiliation: Optical and Semiconductor Devices Group, Department of Electrical and Electronic Engineering, Imperial College London, Exhibition Road, London SW7 2AZ, UK. osydoruk@imperial.ac.uk
authors.forename: O
authors.initials: O
authors.lastname: Sydoruk
authors.forename: R R A
authors.initials: RR
authors.lastname: Syms
authors.forename: L
authors.initials: L
authors.lastname: Solymar
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007909:Lenses; D008029:Lighting / Q000295:instrumentation*; D008962:Models, Theoretical; D012666:Semiconductors; D020349:Surface Plasmon Resonance / Q000295:instrumentation*; D055053:Terahertz Radiation