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

Volume

29

Issue

14

fYear

2011

fDate

7/15/2011 12:00:00 AM

Firstpage

2116

Lastpage

2125

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;

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/JLT.2011.2152364

Filename

5765414