Longitudinal spatial hole burning and associated non-uniform current and carrier density profile as a power limit in high-power diode lasers

High-power diode lasers use long resonators and asymmetric facet reflectivities, leading to longitudinally varying photon density (recombination rate) and early power saturation due to spatial-hole-burning. We summarize recent experimental studies into the relation between device geometry and local current and carrier densities to high powers (10W per 90µm stripe) and compare these to simulation. We use custom devices with segmented contacts (local current density) or back-side window (carrier density and temperature). Strong non-uniformity is observed that increases with bias, above prediction. Local heating at the front facet induces non-saturating carrier accumulation at the stripe edges, a key source of non-uniformity.