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 2x10(10)/cm(2) for a 50 Angstrom GaAs coupling barrier (QW to QD) to 3x10(10)/cm(2) for a 5 Angstrom barrier. The improved QD density and uniformity, as well as improved carrier collection, make possible room-temperature continuous-wave (cw) QD+QW laser operation (a single InAs QD layer) at reasonable diode length (similar to1 mm), current density 586 A/cm(2), 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. (C) 2001 American Institute of Physics.