Morphology and shape dependent characteristics of InAs/InP(1 0 0) quantum dot laser grown by gas source molecular beam epitaxy

We report on the low-dimensional InAs quantum dot lasers based on the InP(1 0 0) substrate grown by gas source molecular beam epitaxy. The active regions of laser consist of fivefold-stacked InAs layer with thickness of 3.0 and 3.5 monolayers (MLs), respectively. Ridge waveguide quantum dot lasers were fabricated and the characteristics of the lasers were carefully examined under continuous-wave mode. A laser with InAs thickness of 3.0 MLs shows a better performance than that of laser comprised of 3.5 MLs InAs. The deteriorated performance from 3.5 MLs lasers is attributed to the morphology and shape of quantum dot elongated along [0 1 –1] direction, which partly decrease quantum efficiency and density of states.