Title :
Evolution of Highly Confined Surface Plasmon Modes in Terahertz Quantum Cascade Laser Waveguides
Author :
Tanvir, Huda ; Rahman, B.M.A. ; Kejalakshmy, N. ; Agrawal, A. ; Grattan, K.T.V.
Author_Institution :
Sch. of Eng. & Math. Sci., City Univ. London, London, UK
fDate :
7/15/2011 12:00:00 AM
Abstract :
The evolution of surface plasmon (SP) supermodes through the effective coupling of isolated SP modes in a semiinsulating quantum cascade laser (QCL) waveguide is thoroughly discussed here. The effect of varying the material and geometric parameters of GaSb/AlGaSb QCL operating at 3.0 THz are thoroughly studied using a full-vectorial finite-element method. It was observed that this structure is prone to mode degeneration caused by resonant interaction of the lasing mode with a higher order plasmon mode. An optimized design is also proposed to suppress such adverse affects and highly divergent field profiles arising from the generation of higher order lateral modes.
Keywords :
III-V semiconductors; aluminium compounds; finite element analysis; gallium compounds; laser modes; optical waveguides; quantum cascade lasers; submillimetre wave lasers; surface plasmons; GaSb-AlGaSb; frequency 3.0 THz; full-vectorial finite-element method; isolated SP modes; lasing mode; mode degeneration; surface plasmon modes; terahertz quantum cascade laser waveguides; Doping; Indexes; Metals; Optical waveguides; Plasmons; Quantum cascade lasers; Finite-element method (FEM); quantum cascade lasers (QCLs); surface plasmon modes (SPMs); terahertz (THz) waveguides;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2011.2152364
