Stimulated Emission and Gain Measurements from InGaN/GaN Heterostructures

InGaN/GaN Heterostructures were deposited on c-plane sapphire substrates by atmospheric pressure Metalorganic Chemical Vapor Deposition (MOCVD). A frequency tripled modelocked Ti-sapphire laser with a 250 fs pulse operating at 280 nm was used for photoexcitation. Photopumped stimulated emission was observed from InGaN/GaN single heterostructures (SH’s) in both edge and surface emitting configurations. A sharp threshold at the onset of stimulated emission and a strong nonlinear dependence of output emission on input power density was observed. Distinct Fabry-Perot modes corresponding to both cavity configurations were also observed. Gain coefficients were measured from an In0.14Ga0.86N film using the method developed by Shaklee and Leheny for the edge emitting configuration.