Sex wins over drugs AND rock and roll.
That’s my how well my kiloWatt laser could focus, 1 KW into a spot 0.3 mm across, which makes it ten million times brighter than the sun. Hence it would melt metal in a thousandth of a second. The beam distribution should be smooth and nicely round. The top right picture shows the cross-section of the beam and frankly, its crap. But hey, we were glad to get that particular laser to turn on, let alone a decent Gaussian beam.
How did I measure the beam, bearing in mind the melty? With a very small mirror on the end of a cantilevered needle, spinning around at ludicrous speed, so it flicks through the beam in a very short time, then spends the rest of each rotation cooling down. Like this. And all this high-tech rotating-needle measurement kit was run off an Atari ST, booting off floppies. Did the job nicely.