Rights Creative Commons: Attribution 3.0 Hong Kong License Interdiffusion effect on the gain of InGaAsJlnP quantum well laser

Lattice-matched Ino53Gao47As/InP quantum well (QW) structures are of considerable interest in photonic application since they enabled device operation in the 1.3tm to 1.55j.im wavelength range which is of importance for optical communication systems. The process of interdiffusion modifies the as-grown square QW to a graded QW which alter the subband structure and optical properties of the QW. Thus it provides a useful tool for bandstructure engineering. The interdiffusion process of InGaAs/InP QW provides more degrees of freedom than AlGaAs/GaAs QW system since interdiffusion can occur for group-Ill (In, Ga), group-V (As, P), and groups III plus V together. These are determined by the temperature and chemical environment used during annealing of the QW structure. The effect of interdiffusion on the laser performances of InGaAs/InP QWs is also studied base on these different types of diffusion processes. It is found that the operating wavelength shows both a red shift and a blue shift depending on the types of diffusion process. It is also found that group-Ill interdiffusion gives the best performance of InGaAs/InP QW laser when comparing to the other two types of interdiffusion in terms of a smaller threshold carrier density