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

The understanding of material quality and luminescence characteristics of I nGaAs-GaAs quantum dots (QD's) is advancing rapidly. Intense work in this a rea has been stimulated by the recent demonstration of lasing from a QD act ive region at the technologically important 1.3-mu m wavelength from a GaAs -based heterostructure laser. Already, several groups have achieved low-thr eshold currents and current densities at room temperature from In(Ga)As QD active regions that emit at or close to 1.3 mu m, In this paper, we discuss crystal growth, QD emission efficiency, and low-threshold lasing character istics for 1.3-mu m InGaGs-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( 2) under continuous-wave (CW) room temperature (RT) operation. At 4 K, a re markably low threshold-current density of 6 A/cm(2) is obtained.