Optically pumped InGaN/GaN double heterostructure lasers with cleaved facets

Optically pumped laser action is demonstrated in an InGaN/GaN double heterostructure with a 1000 Å thick InGaN active region. Hydride vapour phase epitaxy (HVPE) is used to grow a 10 μm thick GaN buffer layer on (0001) sapphire, and the GaN/In_0.09Ga_0.91N/GaN double heterostructure is subsequently grown by metal organic vapour phase epitaxy (MOVPE). 1 mm long cavities are produced by cleaving the structure along the (101¯0) plane of the sapphire substrate. Optical pumping at room temperature with a pulsed nitrogen laser yields an incident threshold power density of 1.3 MW/cm². Above threshold, the differential quantum efficiency increases by a factor of 34, the emission linewidth decreases to 13.5 meV, and the output becomes highly TE polarised