Light-current characteristics of highly p-doped 1.55 μm diffraction-limited high-power laser diodes

The variation of the light-current characteristics of diffraction-limited high-power laser diodes is investigated with different p-doping profiles in the two-step separate-confinement heterostructure (SCH) 1.55-μm InGaAs-InP laser structure. A dramatic increase in the optical output power is observed in the structure with high delta doping at the heterointerfaces and moderate doping at the thick SCH layer. In the structure, a continuous-wave output power of about 0.8 W at a temperature of 15 °C was obtained with the nearly diffraction-limited central lobe of the far field. Such an improvement of device performance is attributed to a reduction of the injected carrier overflow into the SCH layer.