Room-Temperature Continuous-Wave Operation of InGaN Multiple Quantum Well Laser Diodes with an Asymmetric Waveguide Structure

Room-temperature continuous-wave (cw) operation is demonstrated with InGaN multiple quantum well laser diodes which incorporate an asymmetric waveguide structure. The laser heterostructure was grown on a-face sapphire substrates by metalorganic chemical vapor deposition. Threshold currents as low as 107 mA with threshold voltages of 6.5 V have been obtained under cw conditions at 20 degrees C. The emission wavelength is near 402 nm with output powers greater than: one mW per facet. Under cw conditions laser oscillation is observed up to 25 degrees C. The room-temperature cw operation lifetimes, measured at a constant output power of 0.5 mW, are approximately one hour.