mechanical blanking / scanner blanking info

[Lexat8]

Good evening good folks of PL,
Looking into putting together a mechianic blanking system for a large beam dia projection system, 9-10mm. I would be very interested in any info/advice/diagrams or photos fellow members might be able to give me for either focused knife edge, pinhole or retro-reflective sytems that they may have designed or used. Iv'e think that I've read all the posts on PL, but keep getting side tracked by other interesting post! I wondered if any has the fotos that came with this post:

http://www.photonlexicon.com/forums/...ing-looks-like

The only reason I ask is that I've just got a job to go to California to set up some scanners with blanking for a laserscope for show use for some DJ type bloke.

No just JOKING!

I really am looking for the above if any one can help.

Thanks in advance

Lex

[mixedgas]

for normal beams
Most people like retro, I like pinhole, I've also done flag with telescopes...
Its all about the same, retro is just faster because it has twice the path length... retro plus pinhole cleans things up a bit, ie after you pass the retro, you go through a mask with a hole in it..

Pinhole is out for you by sheer size, and retro is going to need a huge mirror, which means a slow galvo , this starts to make flag with telescopes look good.

How long a room do you have for a folded path, or is this a microprojector ??

Steve

[Lexat8]

for normal beams
Most people like retro, I like pinhole, I've also done flag with telescopes...
Its all about the same, retro is just faster because it has twice the path length... retro plus pinhole cleans things up a bit, ie after you pass the retro, you go through a mask with a hole in it..

Pinhole is out for you by sheer size, and retro is going to need a huge mirror, which means a slow galvo , this starts to make flag with telescopes look good.

How long a room do you have for a folded path, or is this a microprojector ??

Steve

Hello Steve,
Thanks for your comments. I'm looking into a project using a CuBr for 'skywriting' idea that I've had knocking around for a while. Objective would be to scan simple corperate logos to cloud base using EMS 4000 scanners @ 24k. I'd like to keep the intire unit as small as possable, so an additional optical deck would be possable. For this reason I'm really looking to see what's been done already, to check that I'm not barking up the wrong tree. Should you be able to point me in the right direction for any photos, in particular of telescope/ flag systems it would be a great help.. Still it's still just an idea, so please don't waste any time.

Many thanks

BTW. I thought that your last post on the 'djallen' saga was rather touching, if you don't mind me saying.

Cheers

Nigel

[mixedgas]

The equal lens case, two positive lens, say just for example, 50 mm focal length, 100 mm apart. The first lens focuses the laser to a point. You place the blanking flag at the focal point. The second lens takes the expanding beam after the focal point and makes it parallel again. You can also use this trick to fit the beam onto smaller scanners by downcollimating it, or to expand it by changing the ratio of the lenses. The lensmakers equation for thin lenses lets you determine what you get, with a small error, say 5% or less, for the fact that the beams are gaussian and thus not quite parallel.

Spektronika sells a lens to fit the beam onto the scanners, LMR had it on his CVL.

Steve

[dsli_jon]

hey Nigel -

Objective would be to scan simple corperate logos to cloud base using EMS 4000 scanners @ 24k.

PM-me your email - I have several retro-style blanking designs for the EMS 4Ks w/ up-to 14mm mirs - sounds like you're using the ones with a 9.5mm aperture; that's perfect, and the design is 'flexible' to accommodate table-sizes... we've seen really, really nice results with an about 8mm KTP beam... check a few examples, here:

http://www.youtube.com/watch?v=3bRUSP5YHXw

http://www.youtube.com/watch?v=HBxRFek-qNs

http://www.youtube.com/watch?v=o9Lp2I4RVBc

...I'd post pix for ya / others, here, but I don't want to end up 'inadvertently aiding' a certain DJ / Blockhead, there... if/when he gets a Variance, I might feel more inclined to post pix... meantime, happy to share with you via email..

cheers...
j

[Lexat8]

The equal lens case, two positive lens, say just for example, 50 mm focal length, 100 mm apart. The first lens focuses the laser to a point. You place the blanking flag at the focal point. The second lens takes the expanding beam after the focal point and makes it parallel again. You can also use this trick to fit the beam onto smaller scanners by downcollimating it, or to expand it by changing the ratio of the lenses. The lensmakers equation for thin lenses lets you determine what you get, with a small error, say 5% or less, for the fact that the beams are gaussian and thus not quite parallel.

Spektronika sells a lens to fit the beam onto the scanners, LMR had it on his CVL.

Steve

Thanks Steve, I'll look into that.

Regards

Nigel

[Lexat8]

hey Nigel -



PM-me your email - I have several retro-style blanking designs for the EMS 4Ks w/ up-to 14mm mirs - sounds like you're using the ones with a 9.5mm aperture; that's perfect, and the design is 'flexible' to accommodate table-sizes... we've seen really, really nice results with an about 8mm KTP beam... check a few examples, here:

http://www.youtube.com/watch?v=3bRUSP5YHXw

http://www.youtube.com/watch?v=HBxRFek-qNs

http://www.youtube.com/watch?v=o9Lp2I4RVBc

...I'd post pix for ya / others, here, but I don't want to end up 'inadvertently aiding' a certain DJ / Blockhead, there... if/when he gets a Variance, I might feel more inclined to post pix... meantime, happy to share with you via email..

cheers...
j

Hello Jon,
Thanks for the clips. Thats just what I'm talking about on here, just watched those, and then some more, and a few other, then found....... another hour gone! Have PM'd you my email.

Thanks

Nigel