The laser arrived yesterday. The laser beam is bright but I'd like it to be brighter if possible. I want the beam to be seen from a few kilometers. So I assume getting the single element M9*0.5 lens would make it more visible. I measured the copper lens holder or how it's called and it measures 9mm in diameter. The actual lens measures 5mm in diameter. So I guess this lens I want to buy would fit https://www.ebay.com/itm/405nm-445nm-488nm-515nm-520nm-Laser-Lens-MP9x9mm-Laser-Collimation-Glass-lens-x1/261445531997?_trkparms=aid=555018&algo=PL.SIM&ao=2&asc=20180306143914&meid=4a2a4a17d0f54db5bf717144ab62cbbf&pid=100935&rk=1&rkt=12&mehot=pp&sd=262228356312&itm=261445531997&_trksid=p2056116.c100935.m2460 If I got the new lens do I push out the old copper one forcibly with a stick or something and slide in the new one? Would getting the lens be worth it? Or is it just a waste of 7 dollars?
You are not going to visually notice the slight increase in output by changing the lens. You would notice it on a Laser Power Meter.
It is what it is.
Output power does not directly translate into visual brightness. It takes 4X the output power to double the the visual brightness so a 4W blue laser would be 2X as bright as the one you have.