Title :
InAs-InAsxSb1-x type-II superlattice midwave infrared lasers grown on InAs substrates
Author :
Zhang, Yong-Hang ; Miles, Richard H. ; Chow, David H.
Author_Institution :
Hughes Res. Labs., Malibu, CA, USA
fDate :
6/1/1995 12:00:00 AM
Abstract :
This paper reports a detailed study of InAs-InAsxSb1-x type-II superlattice (SL) midwave infrared laser structures, in which the band-to-band radiative transitions are spatially indirect, from extended electron states in the conduction band to relatively localized heavy-hole states in the valence band. Due to the large valence band offset between InSb and InAs, the effective bandgap of InAs-InAsxSb1-x type-II SL can cover a broad infrared wavelength range, from 3.0 μm to far infrared (>10 μm). Under CW optical pumping, stimulated light emission is observed from laser structures consisting of InAs-InAsx Sb1-x type-II SL active regions capped by AlAs0.16 Sb0.84 cladding layers. The operating wavelengths are around 3.4 μm, which is in good agreement with theoretical modeling. The overlap between electron and hole wavefunctions along the growth direction is calculated to be 0.89. Equivalent CW threshold current densities are 3.3 A/cm2 and 56 A/cm2 at sample temperatures of 5 K and 95 K, respectively. The corresponding characteristic temperature (T0) is 32 K. These results demonstrate that the InAs-InAsxSb1-x type-II SL is a very promising candidate material for midwave infrared semiconductor lasers
Keywords :
III-V semiconductors; conduction bands; current density; energy gap; indium compounds; laser transitions; molecular beam epitaxial growth; optical fabrication; optical pumping; quantum well lasers; semiconductor superlattices; solid phase epitaxial growth; stimulated emission; valence bands; 3 to 10 mum; 3.4 mum; 32 K; 5 K; 95 K; AlAs0.16Sb0.84; AlAs0.16Sb0.84 cladding layer; CW optical pumping; CW threshold current densities; InAs substrates; InAs-InAsxSb1-x; InAs-InAsSb; band-to-band radiative transitions; candidate material; characteristic temperature; conduction band; effective bandgap; electron wavefunctions; extended electron states; hole wavefunction; laser structures; midwave infrared semiconductor lasers; operating wavelengths; stimulated light emission; type-II superlattice midwave infrared lasers; valence band; Charge carrier processes; Electrons; Laser modes; Laser theory; Laser transitions; Optical pumping; Photonic band gap; Pump lasers; Superlattices; Temperature;
Journal_Title :
Selected Topics in Quantum Electronics, IEEE Journal of
DOI :
10.1109/2944.401267
