AR coated projector window question

[kitatit]

Hi Guys,
I'm about to buy an AR coated window for my projector build.

The windows I'm looking at are in the link below.
http://www.edmundoptics.com/onlineca...w=21&PageNum=2

The two windows I'm considering are both 4inch x4inch. The only difference is, one is 1mm thick and the other is 3mm thick.

The lasers I'm going to buy are;
642nm red
532nm green
445nm blue

Scan angle is 54deg max

I think I'd like to go for the 1mm but I fear a window if this size might be a bit too fragile.

If I decide to play it safe and get the 3mm window, would there be any added artifacts when scanning through 3mm of AR coated glass(both sides) compared to 1mm.

I imagine any such problems would only be noticeable at wider scan angles.

Am I worrying about nothing or is this something that would cause problems when doing graphics?

Anyones thoughts on this would be appreciated.

Thanks
Kit

[dave]

Hey Kit,

I reckon you are worrying about nothing there. I have never had any issues with ar glass, and actually the only issues I have with standard glass is a bit of loss.

We used the Edmund stuff in our yags, and dammed if I can even see the glass!

Hi Guys,
I'm about to buy an AR coated window for my projector build.

The windows I'm looking at are in the link below.
http://www.edmundoptics.com/onlineca...w=21&PageNum=2

The two windows I'm considering are both 4inch x4inch. The only difference is, one is 1mm thick and the other is 3mm thick.

The lasers I'm going to buy are;
642nm red
532nm green
445nm blue

Scan angle is 54deg max

I think I'd like to go for the 1mm but I fear a window if this size might be a bit too fragile.

If I decide to play it safe and get the 3mm window, would there be any added artifacts when scanning through 3mm of AR coated glass(both sides) compared to 1mm.

I imagine any such problems would only be noticeable at wider scan angles.

Am I worrying about nothing or is this something that would cause problems when doing graphics?

Anyones thoughts on this would be appreciated.

Thanks
Kit

[pelosh]

We do sell 1 & 2mm if that helps

[andy_con]

We do sell 1 & 2mm if that helps

ah your still alive martin, we didnt see you at the meet?

you got a price for the glass?

[pelosh]

Yeh, I was bit busy with lasers but somewhere else...

http://www.synchrovision.co.uk/produ...ive-window-ARW

[Eidetic]

I'd recommend the 3mm thick window at that size. Just for mechanical reasons. The only optical reason would be flatness, and the thicker one will probably have flatter surfaces too. Doesn't Edmund have plots for their coatings? There might be a better AR coating at that average angle.

[danielbriggs]

I bought a 3" disc of that a while back. Top stuff. You won't find anything cheaper with higher transmittance.
I ended up going for the 1mm in the end, only cos the 3mm was out of stock in that size for a while...
If I chose again, 3mm sounds a better choice

[dsli_jon]

Hey Kit...

Sorry for not gettin back to ya on the emails, there, m8 - been pretty slammed, as-usual but next week opens-up a bit for me, so I'll get back atcha...

I also heartily recommend the 'CDAR' - the stuff is pretty-well 'invisible', and yes, 3mm would be 'safer' for any chance-knocks... And like Sir Dave said (...whatup Dave? , no worries on 'abberation' from thickness...

...One thing we have always done is mount is at a slight (like 10˚ or less, is fine) angle, base-to-top, this way, whatever minute R will not be retro'd back into your galvos, but, rather, up into the 'ceiling' of your box... ie:



...and the R % is so slight, that worry over 'eye-safety' from the angled-window shooting 'up' when your box is open, is pretty-nil... 'regular' float-glass is at least 10% R, so there you have more 'worry' over 'back-R'... especially when your window is on a 40W puppy! (10% of 40W is just a tad much to 'ignore'...

...One bloke reported that the 'CDAR' does not do so-well for those with the 405s in their rig, but it does not appear you will have that 'worry' since you are running 445...

on the CDAR and chat with ya soon, m8...
cheers..
j

[kitatit]

Hi guys

Thanks a heap everyone for your ideas and explanations

It's settled, 3mm it is.

Jon, I never would have thought of tilting the window like that. It makes real sense.
Stay tuned for some tilted window SolidWorks projector models being posted soon.

Ah, once again, I've come to the right place.

Is there nothing PL can't do?

Thanks
Kit

[blowfly]

Hey Jon and Kit,

What's the reason for tilting the glass to prevent it from reflecting back in the galvos? Does this protect the equipment somehow or produce a better beam?

Also wondering, how do you guys typically mount the glass? I was thinking about using glue but that might get messy if the glass ever needed to be replaced. It would be cool if someone sold some sort of clip and shutter assembly that had a clip to hold the glass on the inside and a metal safety shutter on the outside.

See ya,
Mike