10 W near-diffraction-limited pulsed power from Al-free phase-locked antiguided arrays

10 W peak-pulsed power emitted in a beam pattern 2×diffraction limit is obtained from a 40-element, 200 μm-aperture Al-free phase-locked antiguided array (λ=0.98 μm). 60% of the power resides in the central lobe, and the differential quantum efficiency is 54 % for 1 mm-long devices. The devices were fabricated by a two stage self-aligned etch-and-regrowth process. In the first stage, the strained InGaAs double quantum well (DQW) active region and GaAs guide layer were grown by low-pressure MOCVD. High-index GaAs material was then selectively removed to define the element regions, after which the p-InGaP cladding and GaAs contact layers were regrown