Postgrowth band gap trimming of In As ∕ In Al Ga As quantum-dash laser

The authors demonstrate the selective postgrowth band gap engineering and the fabrication of band gap tuned laser in InAs-InAlGaAs quantum-dash lasers grown on InP substrate. The process utilizes nitrogen implantation to induce local defects and to enhance the group-III intermixing rate spatially upon the thermal annealing. Compared with the as-grown laser, intermixed laser with wavelength shifted by 127 nm shows a 36% reduction in threshold current density and produces a comparable slope of efficiency. The integrity of the intermixed material is retained suggesting that intermixing process paves way to planar, monolithic integration of quantum-dash-based devices.