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Thread: AOM option?

  1. #11
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    Quote Originally Posted by 300EVIL View Post
    http://cgi.ebay.com/ws/eBayISAPI.dll...m=360109022342

    This one went for pretty cheap. I've been watching them too.
    Wow that went cheap!

  2. #12
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    Hey Jonathan -

    Quote Originally Posted by platinum View Post
    -will this work for my ~3 watt DPSS? Is this a stupid question?
    No, not a stupid?? at all, dude! the answer is yes, if it is the 'MG' we've been chatting about, but 'efficiency' is the true question for you, in considering using an AOM for blanking a Melles...prime reason being polarization...

    The trouble is, Melles beam characteristics are somewhat wacky - see HERE - the thing is not perfectly vertically polarized, so unless you are able to determine the exact angle of your polarization (since I don't know which model you have, and some of the older MGs were like, pol'd at nearly 45˚...blech! it will be tricky to get your AOM aligned to get peak efficiency - also, the beam comes out
    at a slight angle, so unless you correct for that with, say an MM-1, shooting into the aperture of the AO, you're gonna get pretty awful efficiency - between these undesirable characteristics, you could lose as much as 50% when it could only be 20-30% - when used with a matched-polarization ion laser, for example, you can get efficiency as high as 80% - only a 20% loss...

    Now, mechanical blanking (galvo) is not nearly as 'lossy' but it will be much 'slower' than AOM blanking - depends on what you are mostly going to project - if it is mostly atmospherics, beams, and 'stock' graphics, well, galvo blanking should be more than fine. But if you intend to do a lot of very highly-detailed graphics (ie: Corporate logos sometimes can be a nightmare, cause there is only so much detail they will let you 'toss out' when simplifying for a laser show...) or lots of raster graphics - those usually demand you use an AO for blanking...

    Also depends on your 'typical venue' - perhaps 1.5 - 2W (assuming you were getting 3W out of your MG) will be more than enough power for your 'typical' gigs / size of venue...

    Interestingly, PL-member LesioQ has these FS (just found it by chance, looking for pix of G-120s with heater-blankie to post)...

    http://cgi.ebay.pl/XY-laser-Blanking...1%7C240%3A1318

    ...pretty nice bit of kit for $250., but G-120s are pretty slow galvos - even with 'TurboTrack' amps, they can't even come close to the performance of a set of properly tuned 6215s - or, even better, IMO, Eye Magic 4000s - we use these pretty much for everything, and even with galvo blanking, get great results... HERE is another-angle shot of the G-120 'XYI' head, just fer kicks...

    I can share with you the design we use for EMS galvo blanking, (if you ended up getting those galvos) - there are several 'off the shelf' designs already out there for Cambridge - HERE is one for 6800s - PL Member, OSLS should stock ones for 6210s, etc...

    Anyhoo, that's my 2¢ about AO vs mechanical blanking...

    peace..
    j
    ....and armed only with his trusty 21 Zorgawatt KTiOPO4...

  3. #13
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    Thanks for the info. I was also considering using a DT40 for mechanical blanking. I haven't seen it done yet, but Dave said he could sell me one scanner/amp/mount instead of the normal pair, if needed. (this would be in addition to my existing DT40 pair)

    The thing I'm trying to decide presently is whether to build a new enclosure or stick with the Mobo platform. I'm leaning towards keeping the Mobolazer since it gives me all sorts of coverage options that one scan set can't handle. Additionally, there's the variance paperwork to consider.

    -Jonathan

  4. #14
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    Cool You want AOM's?

    I've got two Isomet AOM's (1205c's) with the original drivers. Bought them from Gary Staddler (yeah, of Burning Man fame - also the guy that designed the single phase Aurora power supply for medium frame argons) back in 2002. Never really messed with them all that much; they've been on a shelf as a "rainy day" project ever since.

    I'd be willing to let them go for what I paid for them ($150 each - plus shipping).

    Adam

  5. #15
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    Default Re: Buffo

    I would like to tentatively call dibs on one of those AOMs. I slight bit of further research is required.

    -Jonathan

  6. #16
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    Smile

    Duely noted!

    I played around with one of them around 3 years ago. Built a power supply for it and tried to test it. (They need +28 volts, +5 volts, and -5.2 volts, or something close to that, at less than .7% ripple... Very *clean* power requirements.)

    Anyway, I got it all set up, but since I didn't know anything about AOM's at the time (bragg angle was a foreign concept to me back then, as was the fact that you need to use a polarized laser to start with) I never got anywhere with it. (Like a dumb ass, I was using a green pointer to test it. When it acted like a chunk of glass instead of an optical blanking device, I got discouraged and packed up the whole mess.)

    Here's a link to the thread where we discussed it. (After I had packed it up.) Never did revisit the project... Got interested in lots of other projects (including building an RGB projector) and never looked back.

    Adam

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