445nm lensing options - discuss them all here!

[norty303]

Ok, in an attempt to try and bring some order to proceeedings, I've started this thread in the hope we might be able to have all relevant discussions about lenses in one place.

To start the ball rolling, I've got some Aixiz modules with standard lenses on the way from Pat, and I've also got some coated lenses from ebay seller laser66 (refered to as 405-G-2) on the way.

In reading about the 405-G-2 lenses on LPF, it appears they don't do too bad a job, but have a lot of 'noise' on the beam in the form of stray artefacts and haze (they surmise this is from internal reflections). In a projector I don't think this would be too much of a problem as this would never even make it onto the galvos.

My plan (if they turn out to be any good) is to add a circular beam shaper to get a nicer profile. As I'm only looking for about 500mW per diode, I can live with a bit of wastage as a trade-off against a nicer profile.

Any thoughts or further ideas?

[stanwax]

Just unmountin one of the standards and placing it closer to the didoe gets a better beam but have not tried installing it in a housing as such - just hovered in front with some tweezers.
Who would have thought the day would come when someone said - I dont care if I loose some 445nm blue cos I only need 500mW.....crazy crazy

Rob

[shrad]

I also have some plans

I ordered sample acrylic fiber optics of various diameters to try different fast axis lenses, though I fear the beam diameter at output aperture... (largest fiber is 2mm dia)

I also have the cheap cylinder lens from heruur when he was still on ebay, we'll see what it does for a job

And finally the anamorphic prism pair of a dead crystalaser DPSS unit, coated for IR but I'll cope with some losses

If I'm able to cleave the fiber correctly, I could perhaps focus the beam into it and recollimate the output

[norty303]

Who would have thought the day would come when someone said - I dont care if I loose some 445nm blue cos I only need 500mW.....crazy crazy

I can't believe I said it actually! Needs a bit of head re-adjustment...

Incidentally, seeing as I have no machine shop, who might be able to fabricate some small press in discs to fit in the front of modules, with slightly varying sizes of aperture for testing?
Or would it be best to test using ally plate and drill/needle file, and get some fabbed once best size is determined?

[mccarrot]

I have a couple of the high quality collimators on the way with 445nm AR coating (only had red on stock)

these lenses are one of the best for red, now lets hope they are also very good for these baby's

http://store.laserextreme.nl/catalog...products_id/79

[Doc]

I can't believe I said it actually! Needs a bit of head re-adjustment...

Incidentally, seeing as I have no machine shop, who might be able to fabricate some small press in discs to fit in the front of modules, with slightly varying sizes of aperture for testing?
Or would it be best to test using ally plate and drill/needle file, and get some fabbed once best size is determined?

To perform this task the aperture would be better sited a small distance away from the lense, like a lollipop with a hole.

[mixedgas]

These actually win in bang for the buck....

7x10 minilathe.

Available from, quite a few vendors.. Including UK ones.

I own two, one for fine work and a second one I picked up for 99$.
I scraped and leveled the ways on the fine one by hand with a chunk of carbide wedged into a holder, took 8 hours but worth every minute. Even unscraped, they are fabtabulous..

http://varmintal.com/alath.htm

I would not give you a pitcher of warm spit for the r8 Minimill, but the origional minilathe is a good investment, and a lot of 3rd parties make support for it.

ie www.littlemachineshop.com

If no one in the UK comes up with what you need, let me know. Measure the barrel inside with a digital caliper and get back to me. Also take a guess at the hole size you need, and state it.

Take a look at the US standard drill table, and specify accordingly. I have the numbered, lettered, and fractional drills to 1/2" and then some.

Steve

[p1t8ull]

I have a couple of the high quality collimators on the way with 445nm AR coating (only had red on stock)

these lenses are one of the best for red, now lets hope they are also very good for these baby's

http://store.laserextreme.nl/catalog...products_id/79

What FL are these blue lenses?

[norty303]

Excellent! I don't think I'll be shelling out for a mini lathe, I'm not sure I could justify the expense, but I am encouraged by the fact nobody has yet said 'this is a bad idea'

I think I'll do some testing first with bodged up blanks, then get some proper ones done for me

[buffo]

I've been thinking about trying a Keplerian Collimator with a pinhole at the focal point to try to clean up the beam a bit. Sure, you'd lose power, but as Norty said - who cares? We only need a few hundred mw!

Adam