Title :
Analysis of terahertz surface emitting quantum-cascade lasers
Author :
Schubert, Martin ; Rana, Farhan
Author_Institution :
Cornell Univ., Ithaca, NY, USA
fDate :
3/1/2006 12:00:00 AM
Abstract :
An analysis of surface-emitting terahertz quantum-cascade lasers operating at wavelengths near 100 μm is presented. The devices use distributed feedback through second-order Bragg metal gratings to generate strong emission of radiation normal to the laser surface. The analysis is based on coupling between the exact Floquet-Bloch eigenmodes of infinite periodic structures in finite length devices. The results show performance of surface-emitting terahertz lasers comparable to edge-emitting devices, with high radiative efficiencies and low threshold gains. Using phase-shifts in the grating, high-quality single-lobe beams in the farfield are obtained.
Keywords :
Bragg gratings; distributed feedback lasers; eigenvalues and eigenfunctions; laser beams; laser cavity resonators; laser theory; optical fibres; periodic structures; quantum cascade lasers; stimulated emission; submillimetre wave lasers; surface emitting lasers; 100 mum; distributed feedback laser; edge-emitting devices; finite length devices; grating phase-shifts; high-quality single lobe beams; infinite periodic structures; low threshold gains; radiation emission; radiative efficiencies; second-order Bragg metal gratings; terahertz surface emitting quantum-cascade lasers; Distributed feedback devices; Gratings; Laser beams; Laser feedback; Laser modes; Laser theory; Optical surface waves; Optical waveguides; Surface emitting lasers; Waveguide lasers; Coupling coefficients; Floquet–Bloch expansion; distributed feedback (DFB) lasers; quantum-cascade laser; surface emission;
Journal_Title :
Quantum Electronics, IEEE Journal of
DOI :
10.1109/JQE.2005.863138
