High continuous wave power, 0.8 μm-band, Al-free active-region diode lasers

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/cm${}^2,$ 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 ${\mathrm{In}}_{\mathrm{0.5}}{\mathrm{(Ga}}_{\mathrm{0.5}}{\mathrm{Al}}_{\mathrm{0.5}}{\mathrm{)}}_{\mathrm{0.5}}\mathrm{P}$ cladding layers. Further improvement is obtained by replacing the p-${\mathrm{In}}_{\mathrm{0.5}}{\mathrm{(Ga}}_{\mathrm{0.5}}{\mathrm{Al}}_{\mathrm{0.5}}{\mathrm{)}}_{\mathrm{0.5}}\mathrm{P}$ cladding layer with thin (0.1 μm) electron-blocking layers of ${\mathrm{Al}}_{\mathrm{0.85}}{\mathrm{Ga}}_{\mathrm{0.15}}\mathrm{As}$ and ${\mathrm{In}}_{\mathrm{0.5}}{\mathrm{(Ga}}_{\mathrm{0.5}}{\mathrm{Al}}_{\mathrm{0.5}}{\mathrm{)}}_{\mathrm{0.5}}\mathrm{P,}$ and a $p$ -${\mathrm{In}}_{\mathrm{0.5}}{\mathrm{(Ga}}_{\mathrm{0.9}}{\mathrm{Al}}_{\mathrm{0.1}}{\mathrm{)}}_{\mathrm{0.5}}\mathrm{P}$ cladding layer. Such devices provide a record-high $T_0$ 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/cm${}^2)$ 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.