Growth, optical and structural characterization of InGaN/GaN/AlGaN optically pumped lasers

A set of InGaN/GaN/AlGaN structures with various structure design and InGaN/GaN active region growth technique was grown by MOCVD on sapphire substrates. 300 K lasing under optical pumping with threshold excitation densities of 13.5 and 40 kW/cm(2) and wavelengths of 405 and 435 nm, respectively, were observed. The AlGaN cladding layer was found to promote mostly the carrier confinement and its influence on optical confinement does not change the threshold excitation density significantly. The influence of structure design on lasing properties is discussed.