The Troll formerly known as Herbert Von Poople-Futtocks
Excellent.
Thanks for sharing.
I've posted a preview clip of this show on my youtube page so that folks who aren't blessed with Pangolin gear can see your work.
If you'd rather I didn't then just drop me a note and I'll remove it.
It's always nice to see new shows mate.
Thanks again.
Say Bill - I've got a question about your original projector layout (back when everything was gas). It appears that you're using a PBS cube to combine a pair of HeNe's... But then you send the resulting beam (which would be randomly polarized) through the AOM to modulate it.
Now, I'll admit that I'm not as familiar with AOM's as I'd like to be, but I was pretty sure that they required a polarized beam....
So what am I missing here?
Adam
Junior Member
Hi Adam,Originally Posted by buffo
The 2 HeNe heads were polarized - and combined with the cube. (So each head was turned so the polarization was at a 90 deg. angle.) The doubled beam was sent to the AOM bounced off a regular front surface mirror. So yes, the AOM was getting a "criss-cross" polarization. The current diode is polarized, but I don't believe it makes a difference at the AOM itself. (The green and blue are not polarized.)
As an aside, since I've gotten questions about it - at the time the projector was originally made (1998), the technology just wasn't quite there yet for solid state. So Steve Heminover (of AURA Technologies) opted for doubling the HeNe that way so we could have an overall brighter image without making the projector itself larger. The nice thing about the AOM's is they do a really nice job with subtle color differences. They do have their drawbacks, but we do like the waste beam (RGB) for use with the lumia wheel. Also, for those interested, the scanners are Cambridge 6800s.
Now the sad part of the story is it's Saturday, I'm off from work. But I woke up early and did some work on the Coldplay laser show we're running this fall. (Ssshhh, it's not publicized yet!)
-Bill
Last edited by billwx; 06-06-2009 at 05:49.
Ach.... I had a brain fart Bill. AOM's are not polarization-dependent. It's PCAOM's that are sensitive to polarization. I got mixed up back there... Sorry!
Adam
Junior Member
Haha! No problem. You had me thinking about it, too! The question did arise when we were planning on doing the switch to solid state.
-Bill
Welcome Bill! Sooooo... About SELEM?
Adam, when do we need to start paying... or did we do that already?
Love, peace, and grease,
allthat... aka: aaron@pangolin
I'm still working on the special guests for SELEM. So far no one has returned my calls or e-mails. I'll give it another week or so and then start an official sign-up thread.
Adam
The Troll formerly known as Herbert Von Poople-Futtocks
Perhaps a review of Post 20 would enlighten you.
Junior Member
Greetings,
I just uploaded another simple and short song module for "Lasershow" by Fountains of Wayne. At the planetarium we haven't decided if this will be a first song or played just before some shows start.
It's called "lasershow.zip" on the FTP server under shows/Pangolin LD2K. I included a text file.
-Bill
The Troll formerly known as Herbert Von Poople-Futtocks
Thanks Bill.
Always nice to see new shows (although I should imagine listening to that tune time after time would be a bit grating).
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