Lenses Available at Stonetek.org - Comparison...

Hmmm... I'll have to take a second look at that lens. I didn't notice that when I checked it. The dot looked nice and round to me.

Of course, I was only doing power measurements in my testing, and not taking pictures of the dot and beam profile...

I just did some more tests on the 405 glass lens, and it still looks exactly like that, focused to infinity. BUT when I adjusted the lens ever so slightly away from the diode it looked perfectly, kinda like the aixiz glass lens. But now the dot is just a little bigger: ~6mm, 0.133mRad. Not a huge difference, it is just very 'touchy'.

Jay - I need to again express my thanks to you regarding this testing - I see it devolved into fictuous beam and dot profiles, though. To everyone concerned (anyone who reads posts on here that is) with an Aixiz Acrylic lens, you do NOT have a collimating lens - it is only a focusing lens, and the "beam profile" will depend on how well you trimmed the back out of it, or if you left the back intact. The entire reason the lenses were made that way is to give the "dot" a more rounded appearance - and it does that by shaving off the edges of the beam, period - no other magic - regardless of distance. The other lenses (GLASS, multi-element) CAN be used to collimate, provided you are using the lenses properly...I'm not an optical engineer, so I don't have the exact terms for you, so don't ask me As far as all the beam shots that Firemylaser did, they look pretty - but the science just is not there, sorry. The diode (check each individual data sheet for details) generates the beam at a HUGELY divergent angle, and again, all these lenses are simply cutting off some of the beam, and focusing the rest of it. To give you a really good example, pour water from a one gallon container (WIDE MOUTH) into a funnel - how does the liquid come out ? perfectly straight, and pretty ? NOPE. ALMOST the same thing, here - with the beam coming from a diode like this :

-=]< <-----the "<" represents the beam

Once you take the divergent beam, and slap a lens in front of it like this :
<= You see how the ANGLE will make the beam "bounce" around inside the lens housing ? THAT is how we amatures get the funky beams and dots that we get. If we used a fast aixs correcting lens, the HUGE angle would be reduced, more of the useful part of the beam would make it STRAIGHT through the lens, and we would get a much nicer beam/dot out of our DIY diode lasers. FML - you did great work with your pictures, and trying to show folks what some people might miss as far as dots go, but unfortunately, it is all window dressing - I am not gunning for you, or making fun of you, simply changing gears back into how I used to be, and SHARING knowledge - please accept my huge post as such, and not as a personal attack.

As Jayrob stated in a previous post, we all have plenty to learn about lasers, electronics, life, etc - NONE of us are experts in any of the above mentioned fields....some may have a tad bit more knowledge in certain areas, but SHAME ON YOU if you don't share ! THAT is the true mission of this forum, unless Avery's brain has melted into a gelatinous goo since I first joined.....I don;t think that has happened !

Greg
All spelling errors are intentional....or not..... you figger it out, it doesn't matter to me