High-power 808 nm lasers with a super-large optical cavity

We present a detailed design and experimental study of diode laser structures emitting at 808 nm based on the combination of a GaAsP quantum well with well-established AlGaAs waveguide structures. By increasing the thickness of the confinement layers of the laser structure, its vertical far field divergence is reduced down to 15° with only a small increase of the threshold current and small loss of efficiency. 200 µm aperture 'broad area' devices achieve at a heat sink temperature of 25 °C a continuous wave (CW) output power of more than 15 W with a wall-plug efficiency of 50% with a vertical far field divergence of 18°. This output power illustrates the excellent high-power performance by using super-large optical-cavity structures with improved beam characteristics in comparison to the conventional broad waveguide lasers.