Output window for small projector

[weartronics]

Hi Photonlexicon,

I want to put an output window in front of the scanners in a small laser projector (532nm 100mW). I found these parts which could be suitable in size

http://cgi.ebay.com/ws/eBayISAPI.dll...m=130174983329
http://cgi.ebay.com/ws/eBayISAPI.dll...m=130183520193
http://cgi.ebay.com/ws/eBayISAPI.dll...m=270238956449

but do you think the 10mm thickness or absence of AR coating will affect the beam quality? What is your experience?

Thanks,

weartronics

[fearfair]

I am interested in the answer to this same question. I have a 1.5w rgb and two 300mw greenies that just have a cutout. I would like to add some glass to the case to keep dust, etc. out of the projector.

In general, what sort of glass should I be looking for. I don't mean to hijack the thread, but it's really the same question that's been asked.

[jmilan]

Same here, I would like to seal the optics.

What kind of glass can you use? and where can you get it...

Cheers,

[-bart-]

I would use an UV-filter as used on photo cameras. They are cheap, available in all sizes (as long as it's round), and of excellent optical quality.

[Pitts]

HI

I have the Edmund Optics glass...

You can find this on their website www.edmundoptics.com

They also have different sizes and show the specs for the glass and all of their gear.

I have used the three mm glass.

Cheers

Ray
NZ

[Jem]

By far the best (and probably cheapest) way is to visit your local camera store and buy a good quality UV filter (or IR filter, just check the transmission curves). Hoya are usually pretty damn good

If you cut a round hole on the front of your projector you can screw/glue the lens straight onto the aperture.

The coatings on these lenses are usually first quality. you can also buy a standard camera lens guard for protection when you're not using the projector.

Cheers

Jem

[MechEng3]

These have the best coatings and minimal loss on transmission of the 425nm to 740nm band of light. The seller also carries a nice snap on cover to keep the dust and finger prints off the lense.


http://cgi.ebay.com/Hoya-55mm-55-S-H...QQcmdZViewItem

[carmangary]

I like the camera filter idea. That way if it gets messy you can chuck it and get a new one. I think I might machine some type of holder at the front of my scanner with a little door that will cover the lens cap and filter just to make sure it doesn't get knocked off when being transported or whatever.

[buffo]

I agree with the camera UV filter idea. I went the long way and purchased a custom piece of AR treated glass (4 inches square) from OneStopLaserShop in Tampa for my projector. It cost nearly $60 for the piece, and I still get some reflection off the face of it. Not a lot, but enough that I was a bit upset that after paying so much for the window I still had visible reflection of around 5% or so.

If I had it to do all over again, I would try the camera UV filter first. The only real problem with the filter idea is that you need to have your galvos mounted *very* close to the window, because those filters aren't very large. (If the scanners are too far away, the window won't be large enough to allow the entire scanned image to fit through the aperture.)

In my case I would have needed to move my optical table a lot closer to the front of the case, and I probably would have had to find an oversize filter as well. Still, I think it would have been cheaper, and I know I would have ended up with less reflection. (Sigh...)

Adam

[loopee]

Hi Weartronics

I actually bought one of these, it was an absent minded moment when I added it to the order for some other stuff from the same seller, I didn't realise that they had no AR coating.

I wouldn't waste your time with them; they drop about 10% of the beam in reflection

P.S. I think you may have bought an argon head (Oatley special) and parts from me off ebay some years back, did you ever get it working?

Troy

I should have also mentioned that I'm refering to the first ebay link you posted