Title :
Room-Temperature GaAs/AlGaAs Quantum Cascade Lasers Grown by Metal–Organic Vapor Phase Epitaxy
Author :
Krysa, Andrey B. ; Revin, Dmitry G. ; Commin, James P. ; Atkins, Chris N. ; Kennedy, Ken ; Qiu, Yang ; Walther, Thomas ; Cockburn, John W.
Author_Institution :
EPSRC Nat. Centre for III-V Technol., Univ. of Sheffield, Sheffield, UK
fDate :
6/15/2011 12:00:00 AM
Abstract :
We demonstrate λ ~ 9 μm GaAs/Al0.45Ga0.55As quantum cascade lasers (QCLs) operating up to 320 K. Metal- organic vapor phase epitaxy has been used throughout for the growth of the devices. Detailed comparison has been carried out for the QCLs with various waveguides and grown on (100) GaAs substrates with different miscut angles towards (111)A. Introduction of InGaP cladding layers into the optical waveguide significantly improves the QCL performance due to a better optical confinement and lower waveguide losses compared with the GaAs-based waveguide. A 20- μm-wide 4-mm-long device with high reflectivity coating on the laser back facet demonstrates room-temperature pulsed output power of 220 mW and a lowered threshold current density of 6.5 kA/cm2.
Keywords :
III-V semiconductors; aluminium compounds; antireflection coatings; claddings; current density; gallium arsenide; laser beams; optical losses; optical waveguides; quantum cascade lasers; vapour phase epitaxial growth; (100) GaAs substrates; GaAs-AlGaAs; cladding layers; laser backfacet; metal-organic vapor phase epitaxy; miscut angles; optical confinement; optical waveguide; power 220 mW; reflectivity coating; room-temperature pulsed output power; room-temperature quantum cascade lasers; size 20 mum; size 4 mm; temperature 293 K to 298 K; threshold current density; waveguide losses; Epitaxial growth; Gallium arsenide; Optical reflection; Optical variables control; Optical waveguides; Quantum cascade lasers; Waveguide lasers; Midinfrared quantum cascade lasers (QCLs); optical waveguide;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2011.2138124
