Very-low-threshold current density 1.29 μm GaInNAs triple quantum well lasers grown by molecular beam epitaxy

Very-low-threshold Ga_0.62In_0.38N_0.007As_0.993/GaN_0.011 As_0.989/GaAs triple quantum well (QW) lasers emitting at 1.29 mum are demonstrated. The laser structure was grown by molecular beam epitaxy after extensive optimisations of growth and in situ annealing conditions. As-cleaved broad-area lasers with a cavity length of 1 mm under pulsed operation showed a record low-threshold current density of 400 A/cm² (~130A/cm²/QW), a high differential efficiency of 0.32 W/A/facet and a characteristic temperature of 94 K in the temperature range 10 to 110degC.