The performance characteristics of 1.3- mu m InGaAsP semi-insulating buried-crescent (SIBC) lasers with Fe- and co-doped InP current blocking layers are compared. Threshold currents as low as 10 mA (Fe) and 8 mA (Co) at room temperature, total differential quantum efficiency of 60%, high-temperature operation up to 100 degrees C, high-power output of 42 mW/facet (Fe) and 30 mW/facet (Co), and 3-dB...