Efficient, high-power, Al-free active-region diode lasers emitting at λ=0.83 μm have been grown by low-pressure metalorganic chemical vapor deposition. Threshold-current densities as low as 220 A/cm2, maximum continuous wave (cw) power of 4.6 W, and a maximum cw wallplug efficiency of 45% are achieved from 1 mm long, uncoated devices with In0.5(Ga0.5Al0.5)0.5P cladding layers. Further improvement is obtained by replacing the p-In0.5(Ga0.5Al0.5)0.5P cladding layer with thin (0.1 μm) electron-blocking layers of Al0.85Ga0.15As and In0.5(Ga0.5Al0.5)0.5P, and a p-In0.5(Ga0.9Al0.1)0.5P cladding layer. Such devices provide a record-high T0 of 160 K and reach catastrophic optical mirror damage (COMD) at a record-high cw power of 4.7 W (both facets). The corresponding COMD power-density level (8.7 MW/cm2)is ∼2 times the COMD power-density level for uncoated, 0.81-μm-emitting AlGaAs-active devices. Therefore, 0.81-μm-emitting, Al-free active-region devices are expected to operate reliably at roughly twice the power of AlGaAs-active region devices. © 1997 American Institute of Physics.