LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Swift Griggs]

On Tue, 19 Jul 2016, Mouse wrote:
> You'd probably know, then - what's the fastest way to deflect a laser 
> beam?

Whoa. Interesting problem since a photon carries no charge and thus you 
can't horizontally or vertically deflect it with a magnetic field. I guess 
that's why folks make things like these:

http://www.newson.be/rhothor.htm

> In particular, I'm wondering how practical it might be to take a laser 
> and turn it into a vector display on a handy blank wall - but that 
> requires some very fast acceleration of the spot, probably faster than 
> mechanical deflection can support (though if I'm wrong I'd love to know 
> it).

I wonder how laser projectors work. The must use some kind of internal 
screen like the ones that use "lamps". I'm guessing they just use lasers 
instead of lamps to get a brightness and longevity boost.

> For example, does piezoelectricity make a crystal distort enough to use 
> it as an optical deflection element in such a scheme? (My guess is no, 
> but I don't actually know.)

I found mention of something like that in this paper:
http://www.sciencedirect.com/science/article/pii/S1875389214002351

It's in the references:
F. Filhol, E. Defay, C. Divoux, C. Zinck, M.-T. Delaye
Resonant micro-mirror excited by a thin-film piezoelectric actuator for 
fast optical beam scanning

That sounds wicked-cool, by the way. If you ever do build something like 
that, please share some video!

-Swift