Room-Temperature Low-Threshold Surface-Stimulated Emission by Optical Pumping from Al0.1Ga0.9N/GaN Double Heterostructure

The difference in the refractive index at around λ=0.37 µm between GaN and Al0.1Ga0.9N is found to be about 0.19. With use of AlGaN/GaN double heterostructures, the threshold power for surface-stimulated emission by optical pumping at room temperature has been markedly decreased to about one-twentieth that of a bulk GaN layer. The mechanism of the stimulated emission in this system is discussed.