Vertical–cavity stimulated emission from photopumped InGaN/GaN heterojunctions at room temperature

Abstract

We report the observation of room temperature violet (415 nm) stimulated emission in the vertical cavity mode from photopumped GaN/In0.25Ga0.75N heterojunctions. The InGaN/GaN heterojunction was deposited over sapphire substrates using low-pressure metalorganic chemical vapor deposition and was of high enough optical quality to achieve room-temperature stimulated emission. The observed emission intensity was found to be a nonlinear function of incident optical pump power density. At threshold we observe a clear line narrowing of the output optical signal from 20 to 1.5 nm full width at half-maximum.