Lasing in the vertical direction in InGaN/GaN/AlGaN structures with InGaN quantum dots

InGaN/GaN structures with dense arrays of InGaN nanodomains were grown by m etallorganic chemical vapor deposition. Lasing in vertical direction occurs at low temperatures, indicating ultrahigh gains (similar to 10(5) cm(-1)) in the active region. Fabrication of an effective AlGaN/GaN distributed Bra gg reflector with reflectivity exceeding 90% enables vertical lasing at roo m temperature in structures with a bottom distributed Bragg reflector, desp ite the absence of a well-reflecting upper mirror. The lasing wavelength is 401 nm, and the threshold excitation density is 400 kW/cm(2). (C) 2000 MAI K "Nauka/Interperiodica".