InAs self-assembled quantum dot lasers grown on [100] InP

Quantum dot lasers containing five stacked layers of InAs quantum dots (QDs) embedded in quaternary InGaAsP are grown on [100] InP substrates. The QD ensemble has a density of 1.5 /spl times/ 10/sup 10/ cm/sup -2/ and emits light at /spl sim/1.6 /spl mu/m at 77 K. Lasing wavelength and threshold current density can be shifted by changing the cavity length of the laser diode and the latter reaches a value as low as 49 A/cm/sup 2/ at 77 K for a gate size of 2000 /spl mu/m /spl times/ 150 /spl mu/m. Temperature dependence of the threshold current is observed implying the presence of thermionic emission increasing with temperature.