Coupled strained-layer InGaAs quantum-well improvement of an InAs quantum dot AlGaAs–GaAs–InGaAs–InAs heterostructure laser

Data are presented showing that, besides the improvement in carrier collection, it is advantageous to locate strain-matching auxiliary InGaAs layers @quantum wells ~QWs!# within tunneling distance of a single-quantum-dot ~QD! layer of an AlGaAs–GaAs–InGaAs–InAs QD heterostructure laser to realize also smaller size QDs of greater density and uniformity. The QD density is changed from 2310/cm for a 50 Å GaAs coupling barrier ~QW to QD! to 3310/cm for a 5 Å barrier. The improved QD density and uniformity, as well as improved carrier collection, make possible room-temperature continuous-wave ~cw! QD1QW laser operation ~a single InAs QD layer! at reasonable diode length ~;1 mm!, current density 586 A/cm, and wavelength 1057 nm. The cw 300 K coupled InAs QD and InGaAs QW AlGaAs–GaAs–InGaA–InAs heterostructure lasers are grown by metalorganic chemical vapor deposition. © 2001 American Institute of Physics. @DOI: 10.1063/1.1430025#