Through the use of a high-quantum efficiency single-quantum-well structure grown by molecular beam epitaxy an output power as high as 3 mW at an injected current of 100 mA with a 50- mu m-wide mesa ...

the structure caused a drawback of increase in on-resistance and turn-on voltage. By applying a newly developed two-step mesa structure consisting of the first inner mesa with partially thinned p-GaN ...