laser show projectors

[george2524]

Hi all,
New to the forum. I love laser light shows saw my first in the Denver planetarium back in 76.
My question is how do they create all the effects?

Sorry for posting in the wrong topic please move to the correct topic.

 

[Grix]

I don't know what kind of laser show they had in the planetarium you visited, but most modern laser shows use laser modules that can be turned on and off quickly, and galvanometers to steer the beam: https://www.youtube.com/watch?v=Gsi-VbSL8eM . Analog signals are fed to the lasers and galvos continuously, forming a projected image.

 

[diachi]

I imagine it was something like this that you seen: Laserium Gallery

Seeing as it was back in '76 they wouldn't have been using laser modules. They'd have been using gas lasers (likely Ar/Kr Whitelights) with AOMs (Accoustic Optical Modulators).

Some of the effects would have been done by galvos I imagine (as Grix said) others would have likely been diffraction gratings and lumias. Lumias are usually just rotating textured pieces of glass that the laser beam passes through. All analog control back then too as far as I'm aware. Seems some people are trying to bring that back and have got some pretty cool effects coming from those efforts.

Actually here is a picture of one of the laserium systems. You can see the diffraction gratings (square, top row) and lumias (round things, middle row).

http://www.photonlexicon.com/gallery/d/3561-2/IMG_1810.jpg
http://www.laserium.com/hardware/CSL_big.gif
What the back side of that second image likely looked like: http://tinyurl.com/zb9re5p

Likely using a laser similar to this for the light source:

Some of the members on Photonlexicon (Some of them visit here too) were involved with laserium at the time so they'd be able to offer some additional information. I may be wrong on some of the information - laserium was well before my time.