so two diodes stacked one on top of the other will go very ok like = then do another pair the same and PBS the two pairs together, drive them a little over spec power and end up with ~2W at 1.5mrad (3mm x 3mm) or further telescope the entire setup to 4mm and lower the divergence to ~1mrad. or 5mm <1mrad. Seams like a neat solution for some crazy red power.
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