445nm beam collimation/correction

[ElektroFreak]

But do you really find it a problem during scanning?
Have you ever had a customer saying, this beamshow sucks because I had seen "wings" around the red.
Or these graphic really sucks because everything is red???

I really don't see the problem.

we now have affordable 445nm power with reasonable beam specs and we are nitpicking about something a normal person would never notice in a projector.

Not personally no.. and I agree about these subtleties being nearly impossible to detect when used in a scanner, but others are far more picky. For them it might be worth investing a little time and effort into the pursuit of near-perfection. To me, all you need to do laser shows is a beam.. it doesn't matter if it's square, round, line, zig-zag, spiral or whatever.. just a beam with low(ish) beam diameter and divergence and good modulation response..

[mccarrot]

Oh, and when adjusting the collimator just slightly out of focus you will get a better beam profile/divergence at distance. just try it.

[Solarfire]

I updated the first post with some new data (Power chart, pics. comments).

cheers!

Frank

[Phredy1]

My plan is to knife edge 2 or 3 445nm diodes and use the O-Like lens and then to put a 3mm pinhole as close to the scanners as possible. Wouldn't that just give me a nice round 3mm beam into the scanners?

I really don't care how much power I lose, I just want a nice clean beam going into the scanners.

Gene

[catalanjo]

Oh, and when adjusting the collimator just slightly out of focus you will get a better beam profile/divergence at distance. just try it.

I do believe this might supply a clue to where the trash is coming from !

How much is "slightly" ? and how much power do you lose as a result ? (approx. naturally)

I don't really trust the edges of the diode much but I do like more power.

Cheers

[mixedgas]

My plan is to knife edge 2 or 3 445nm diodes and use the O-Like lens and then to put a 3mm pinhole as close to the scanners as possible. Wouldn't that just give me a nice round 3mm beam into the scanners?

I really don't care how much power I lose, I just want a nice clean beam going into the scanners.

Gene

I tried it, without doing Fourier transform optics on it, ie 2 lens, special pinhole between the lenses, loose one hell of a lot of power, the pinhole does not work well. Even with a seriously "Phatt" adjustable pinhole that needs Pdiddy's credit card to buy, , I managed to score some serious diffraction right around where the "cleanup" starts. Ie you can only clean up at one distance in space, and then your not scoring well.


A rought explanation is to think of the bad rays coming from the middle of the beam, and only escaping at a beam waist that somehow exists in the far field. Its not your normal "Gaussian" beam by a long ways, its a overlay of a whole bunch of them in parallel or some other nause. (Greatly oversimplified explanation)

Dr Lava's lenses work well, IMHO. I have not yet seen Badger's prisms.

Try running the diode at far less current, but if you wanted a single line 488 aircooled you would have bought one, right?

Steve

[michelrietveld]

Hi all,

i will build a blue 445nm 1W soon, i will use the McCarrot lens/collimator/fitting for 11mm block and prisms at the end, here is a picture of the block, got it from the NL LEM Ilpendam 2010, i guess McCarrot uses the same for his setup and i can confirm that it gives a very good beamshow, you can also judge by the photo's and video's taken at the LEM which are posted on the FTP server.
As soon as i have completed the blue i will share my findings.

[mccarrot]

I just want to comment to the photo's michel Rietveld posted.

Those blocks are universal blocks, you can use them to combine 1, 2 or 3 blue diodes. In front there is a place to clamp the prismpair from the groupbuy (no need for glueing the prisms )

Or you can use them to combine 3 red diodes.
For red you can use 2 methods:
1 knive edge 2 vertical red and and combine a horizontal red with a PBS for the perfect beam (2,5mmx2,5mmx0,8mrad)

or you can knive edge 3 beams so you can combine another block so you can use 6 diodes or even 12 diodes.

And the best thing it is cheap!


The beam on the right with the good divergence is from this modules

[Geetone]

And the best thing it is cheap!

How cheap? I want one!

[mccarrot]

We are thinking of a price of 60-65 euro/block (ex vat) soon available trough my webshop.

We are thinking of offering sets as you also need a minimount and collimators with this setup.

I have attached a better picture, please note the price is only for the metal work.
The prism, collimater and mirrormounts are not included in this price.

size is 70x40mm and with a TEC fitted the beam hight will be 29mm