No abstract

Design and technology developments targeted at increasing both power conversion efficiency and optical output power of GaAs-based diode lasers are under intense study worldwide, driven by the demands of commercial laser systems. The conversion efficiency at the operation point is known to be limited by electrical and optical losses in the p-side waveguide. In this paper an 'extreme, double asymmetric' design to mitigate the impact of the p-side waveguide is studied and compared with a more conventional design. An increase of the efficiency at the highest power is demonstrated, but it is less than expected from simulations.

No abstract

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.