InGaAs quantum dot lasers with sub-milliamp thresholdsand ultra-low threshold current density below room temperature

Continuous-wave operation of InGaAs quantum dot lasers is studied. A very low threshold current of 460 µA is achieved at 200 K for a 5 µm × 1170 µm oxide-confined stripe laser. For a larger stripe width of 11 µm, a threshold current density of 5.2 A/cm2 is demonstrated. The characteristic threshold temperature is ~700 K in the temperature range of 140–200 K, and drops rapidly around room temperature.