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From: will@anasazi.UUCP (Will Fuller)
Newsgroups: net.physics
Subject: Re: deflecting laser
Message-ID: <113@anasazi.UUCP>
Date: Mon, 7-Jan-85 13:33:54 EST
Article-I.D.: anasazi.113
Posted: Mon Jan  7 13:33:54 1985
Date-Received: Fri, 11-Jan-85 06:35:38 EST
References: <10800014@uiucdcsb.UUCP>
Organization: Anasazi, Phoenix Az.
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> 
>   I remember seeing the world map projected onto the silver dome
> in monochrome laser in the EPCOT center, Florida. How did they do that?
> They must have a way of deflecting the laser light to make it 
> does raster scanning. I can imagine only two ways to do this:
> 
> 1) move the laser device mechanically. 
> 2) projects laser through some tansparent medium whose refractivity
>    is electronically controllable.
> 
>   The second one seems to be a more reasonable solution to me. Anyone 
> knowledgeable in the field care to comment on this?
> 
> 
> Kaihu Chen
> uiucdcs!chen

The map might be projected holographically.

Perhaps a raster scan might be achieved  using  either  the  Kerr
electro-optical,  or  the  Voigt & Cotton-Mouton  magneto-optical
effects. The beam intensity could be modulated via a Pockel Cell.

Every time I have  seen  someone  scan  something  with  a  laser
they've  used  some  variant  of  a mirror on an air bearing, and
a linear servo (yawn).

William Fuller
..!terrak!anasazi!will