Effects of Intermixing on Gain and Alpha Factors of Quantum-Dash Lasers

Gain and alpha factors were measured on InAs-InAlGaAs quantum-dash lasers with their heterostructures intermixed by either a dielectric-capping or ion-implantation technique. The laser intermixed by the dielectric-capping technique exhibits a blue shift as much as 93 nm without degrading the laser quality. In comparison, the laser intermixed by the ion-implantation technique has a larger shift but lower differential gain and higher alpha factor. The result implies that quantum-dash lasers of different wavelengths can be effectively integrated on the same chip by the dielectric-capping intermixing technique.