Very low threshold current density room temperature continuous-wave lasing from a single-layer InAs quantum-dot laser

Abstract
Continuous-wave (CW) lasing operation with a very low threshold current density (J/sub th/=32.5 A/cm 2 ) has been achieved at room temperature by a ridge waveguide quantum-dot (QD) laser containing a single InAs QD layer embedded within a strained InGaAs quantum well (dot-in-well, or DWELL structure). Lasing proceeds via the QD ground state with an emission wavelength of 1.25 μm when the cavity length is longer than 4.2 mm. For a 5-mm long QD laser, CW lasing has been achieved at temperatures as high as 40/spl deg/C, with a characteristic temperature T 0 of 41 K near room temperature. Lasers with a 20 μm stripe width have a differential slope efficiency of 32% and peak output power of >10 mW per facet (uncoated)."