user3284: I'm not entirely sure if this is on-topic here, since it's about stage lighting rather than audio or video directly, but I'll give it a shot.
I've been looking at various types of laser stage lighting, and I'm trying to work out how they work internally. I figure the scanning lasers (single fast-moving beam) work by firing a single laser onto a rotating mirror, or a mirror controlled by servos for more precise movements.
However, I can't figure out how the cluster lasers work. I'd guess there's some kind of prism in there, or some trickery with a set of mirrors and lenses that somehow "split" the beam, but I can't quite figure it out. My first thought was a fixed prism, but that wouldn't explain how these devices can spread, focus and rotate the beams.
How do these laser effects usually work?

user674: The way most stage laser effects work is by using a holographic plate or diffraction grating which splits the single beam up into multiple beams. 
[image removed due to a DMCA request from copyright holder]
These then pass to further holographic elements to provide shapes and lines, and these can then be manipulated further with lenses or mirrors.

3284: <p>I'm not entirely sure if this is on-topic here, since it's about stage lighting rather than audio or video directly, but I'll give it a shot.</p>

<p>I've been looking at various types of laser stage lighting, and I'm trying to work out how they work internally. I figure the scanning lasers (single fast-moving beam) work by firing a single laser onto a rotating mirror, or a mirror controlled by servos for more precise movements.</p>

<p>However, I can't figure out how the cluster lasers work. I'd guess there's some kind of prism in there, or some trickery with a set of mirrors and lenses that somehow "split" the beam, but I can't quite figure it out. My first thought was a fixed prism, but that wouldn't explain how these devices can spread, focus and rotate the beams.</p>

<p>How do these laser effects usually work?</p>
 674: <p>The way most stage laser effects work is by using a holographic plate or diffraction grating which splits the single beam up into multiple beams. </p>

<p><em>[image removed due to a DMCA request from copyright holder]</em></p>

<p>These then pass to further holographic elements to provide shapes and lines, and these can then be manipulated further with lenses or mirrors.</p>
