High-Performance Ridge-Waveguide Multi-Stack (N=2, 5 and 10)InAs/InGaAs/GaAs Quantum Dot Lasers of 1.3 μm Range

We have investigated light-current and spectral characteristics of 2-, 5- and 10-stack InAs/InGaAs/GaAs quantum dot (QD) ridge-waveguide lasers grown by MBE. Ultra-low threshold current of 1.43 mA was achieved for 2-stack QD laser. Simultaneous lasing at ground- and excited-states was observed. This effect is accounted for the finite time of carriers capture to the ground-state in QDs. Multi-stack QD structures enables to maintain continuous-wave (CW) ground-state lasing up to the current density of 100×Jth and to achieve the highest output power and efficiency ever recorded for any single-mode lasers of 1.3-μm-wavelength range.