67% CW power conversion efficiency from Al-free 1060 nm emitting diode lasers

1060 nm emitting broad-waveguide-type aluminium-free diode lasers have been optimised for maximum power conversion efficiency (PCE). PCE at 67% is achieved at continuous-wave operation and 25degC heatsink temperature from a 1 mm cavity length, 100 mum stripe diode laser. The improvement is mainly the result of an increase in injection efficiency via optimisation of the bandgap structure, and reductions in operating voltage via doping optimisation of the broad-waveguide structure.