Focusing an Aixiz TTL Module

[NoodleSlayer]

I've purchased one of these 405 nM TTL modules, http://www.aixiz.com/store/product_...d/437/osCsid/c2d8dafd1f5eaab5671f0e8ee4d64784

These are supplied with a glass 3 element lens, adjusted to a collimated beam, and presumably to nominal 150 mW output. Perhaps out of excessive caution, I've not messed about with the focus or disassembled it (yet). If initial experiments work out, I'll probably build a version 2 with cheaper parts, specifically chosen lens, my own driver circuit, etc, but for initial efforts, I figured buying something off the shelf would be the way to get started.

My purpose is to heat a tiny spot, not to set the neighbor's cat on fire at 200 yards, so I think 150 mW should be plenty. 405 was an economical way to get to the 100+ mW range, and I may try later to use this with some UV curing polymers, so that'd be dual use.

So here's my question:

Aixiz says that if I find the appropriate 2 pin tool, the provided lens can be adjusted to focus to a spot. Has anyone here tried that, and have any information on how tight that spot can be dialed in, or how close that focal point can reasonably be brought to the end of the module?

Would swapping in a different lens, eg a G1 or G2 do that better? The alternative is to leave it collimated, and use an external lens, or beam expander plus lens, to try for that tightly focused spot.

Data or suggestions in this area, anyone? Thanks!

 

[wby300]

Not sure if you stillneed an answer on this or not but I figure I will give it just in case. The 3 element glass lens will work fine for collimation, so will the g lenses. The main difference between the 3 lenses will be losses in transmitted light, you probably wont be able to tell a difference in spot size. The light "frequency" has more to do with spot size with these 3 lenses than the lenses do. Now when you get into custom lenses and beam expanders and such, then the lenses will play a major role in spot size. With a 150mw diode you may lose 25mwwith the 3 element and only 10mw with the g-2 or g-3. I dont have exact numbers, just giving an example.

 

[NoodleSlayer]

The project oozes forward, so your reply remains timely.

Preliminary tests suggest a 40% duty cycle is workable. So a little loss here or there doesn't seem a big issue.

Motivated by cowardice (or maybe we'll say "informed caution"), experimenting to date I've left the factory lenses unmolested and concentrated on focusing the beam using some externals from surplusshed. I've yet to carefully measure the width of the spot generated so far, but it's looking hopeful. So for now I think I'll continue in the current direction of leaving the factory lenses as they were set, and using externals to generate my spot.

Thanks!