MBE GROWN MIDINFRARED TYPE-II QUANTUM-WELL LASERS

We have employed molecular-beam epitaxy (MBE) for the growth of mid-in frared (MIR) type-II quantum-well laser structures. These lasers consi st of strain-balanced InAs/InGaSb/InAs/AlSb type-II quantum wells latt ice-matched to the AlSb cladding layers. We have demonstrated opticall y pumped lasers emitting from 3 to 4.3 mu m under pulsed operation. Fo r the 3.2-mu m lasers, stimulated emission was observed at temperature s up to 350 K. The characteristic temperature To at operation temperat ures above ambient was 68 K. Here, we discuss the optimization of the MBE growth of MIR type-II quantum-well lasers, including substrate tem peratures, V/III beam-equivalent pressure ratios, and shutter sequenci ng for better interface control and laser performance.