Continuous-wave low-threshold performance of 1.3-/spl mu/m InGaAs-GaAs quantum-dot lasers

Abstract

The understanding of material quality and luminescence characteristics of InGaAs-GaAs quantum dots (QD's) is advancing rapidly. Intense work in this area has been stimulated by the recent demonstration of lasing from a QD active region at the technologically important 1.3-/spl mu/m wavelength from a GaAs-based heterostructure laser. Already, several groups have achieved low-threshold currents and current densities at room temperature from In(Ga)As QD active regions that emit at or close to 1.3 /spl mu/m. In this paper, we discuss crystal growth, QD emission efficiency, and low-threshold lasing characteristics for 1.3-/spl mu/m InGaAs-GaAs QD active regions grown using submonolayer depositions of In, Ga, and As. Oxide-confinement is effective in obtaining a low-threshold current of 1.2 mA and threshold-current density of 19 A/cm/sup 2/ under continuous-wave (CW) room temperature (RT) operation. At 4 K, a remarkably low threshold-current density of 6 A/cm/sup 2/ is obtained.