Room-temperature operation of InAs quantum-dash lasers on InP (001)

The first self-assembled InAs quantum dash lasers grown by molecular beam epitaxy on InP (001) substrates are reported. Pulsed room-temperature operation demonstrates wavelengths from 1.60 to 1.66 mum for one-, three-, and five-stack designs, a threshold current density as low as 410 A/cm(2) for single-stack uncoated lasers, and a distinctly quantum-wire-like dependence of the threshold current an the laser cavity orientation. The maximal modal gains for lasing in the ground-state with the cavity perpendicular to the dash direction are determined to be 15 em(-1) for single-stack and 22 cm(-1) for five-stack lasers.