High-Efficiency 808-nm InGaAlAs–AlGaAs Double-Quantum-Well Semiconductor Lasers With Asymmetric Waveguide Structures

The InGaAlAs-AlGaAs double-quantum-well semiconductor lasers grown by molecular beam epitaxy show high quantum efficiency and high power conversion efficiency at continuous-wave power output using asymmetric waveguide structures. The threshold current density and slope efficiency of the device are 180 A/cm
²
and 1.4 W/A, respectively. The internal loss and the internal quantum efficiency are 1.1 cm
^-1
and 97%, respectively. The 75% maximum power conversion efficiency is achieved in 100-mum stripe widths 808-nm-emitting laser diodes with 1000-mum cavity length.