Growth of high quality InGaAsN heterostructures and their laser application

Focus of this work is the optimization of growth to achieve high quality laser material for emission at 1.3 μm and beyond. GaAs/GaAsN/InGaAsN heterostructures were grown by solid source molecular beam epitaxy. To achieve optimum crystal quality of InGaAsN heterostructures, growth was followed by a high temperature treatment at about 700°C. The high optical quality of our annealed material is attested by large exciton recombination lifetimes (more than 2 ns). Consequently, a decrease of single quantum well transparency current density down to 100 A/cm² is found and SWQ lasers with threshold current densities as low as 350 A/cm² have been made. This represents clearly the lowest laser thresholds reported so far for emission around 1.3 μm from the InGaAsN material system.