Here's a comparison between a uber expanded 1.4 watt NDG7475 520 nm laser and a 6 watt expanded 450 nm NUBM44 laser. These two hosts are kind of ghetto with the lenses held on by electrical tape, but it gets the job done. The way I have it setup, the NUBM44 uses a lens with too short of a focal length for the spread of the beam before being collimated by that lens, a lot of potential expansion wasted, but doing so the output has absolutely no wings i can see on the beam.
If I don’t do this, the wings are horrible but I could make it about half as much wider and still be without wings, except the telephoto lens has an iris inside which then clips the beam some, even when opened all the way. I should remove that iris and get a solid machined fitting for the lens cone.
Ideally, for both of these pointers I need a set of cylinder lenses inside to match the slow and fast axis closer together to make a square output, instead of a rectangle, but then I would need to expand the beam after correction to get a low divergence output, more complexity, greater loss. When using cylinder pairs, beam correction needs to be done with a collimated beam first, unfortunately.
Wish I had correction ahead of the beams to make the slow and fast axis match better.
I have a JetLasers PLE-PRO 532 nm laser pointer with a 10x beam expander on it next to these two pointers to show scale better, for those of you who are familiar with it.
