Effect of (Al)GaAs/AlGaAs quantum confinement region parameters on the threshold current density of laser diodes

An approach has been proposed for choosing parameters (width and depth) of an (Al)GaAs/AlGaAs quantum confinement region via calculation of the threshold current density of a semiconductor laser. A detailed assessment of its components has made it possible to find criteria for optimising the range of quantum well widths so as to minimise the threshold current for lasers with different heterostructure geometries. The data presented in this paper demonstrate the feasibility of further improving output characteristics of semiconductor lasers by optimising the design and technology of quantum well heterostructures. Owing to this, we have simultaneously reduced the threshold current, carrier escape and internal optical loss, which has allowed us to obtain high (60% to 70%) efficiencies of a semiconductor laser operating in the spectral range 800–850 nm.