Circular beam oxide-confined high-index-contrast ridge waveguide edge-emitting lasers

We demonstrate deep-etched oxide-confined 870 nm AlGaAs HIC RWG edge-emitter lasers with stable single-spatial-mode total output >165 mW. With 3.25 µm ridges, ~0.5 µm of sidewall-smoothing oxide yields a nearly perfect 1.9 µm 1/e
²
circular mode and circularly symmetric ~30° FWHM, M
²
~1.2 output beam.