High power tapered InGaAs/GaAs laser diodes with carbon doped cladding layers grown by solid source molecular beam epitaxy

High power InGaAs/GaAs tapered laser oscillators with a new type of carbon doping in the p-cladding layers grown by MBE are presented. In these devices carbon partially replaces the common beryllium p-dopant near the core region. SIMS depth profiles show, that the carbon doped layer serves as an efficient diffusion barrier for the beryllium in the p-cladding and contact layers. Thus, the previously observed severe beryllium redistribution from the p-cladding layer into the core region of the laser diodes is completely suppressed. In single quantum well (WQW) lasers this doping profile results in low internal losses of 2.6 cm(exp -1). Tapered laser oscillators show output powers as large as 7.2 watts an a maximum power conversion efficiency of 34 %.