Path: utzoo!attcan!utgpu!watserv1!watsci!batman
From: batman@watsci.uwaterloo.ca (Marcell Stoer)
Newsgroups: sci.electronics
Subject: Re: How do you aim a laser? (Watch where you point that, son!)
Message-ID: <301@watserv1.waterloo.edu>
Date: 4 Dec 89 21:54:21 GMT
References: <6220003@hpcupt1.HP.COM>
Sender: daemon@watserv1.waterloo.edu
Reply-To: batman@watsci.UUCP (Marcell Stoer)
Organization: University of Waterloo, Waterloo Ontario, Canada
Lines: 26

In article <6220003@hpcupt1.HP.COM> dclaar@hpcupt1.HP.COM (Doug Claar) writes:
>This is probably a naive question, but how do you aim a laser beam? (I know,
>very carefully!). But seriously, are there non-mechanical methods to aim
>a beam, or must I rely on moving mirrors around? What do things like
>handheld laser barcode scanners and heads-up displays do? Are they
>mechanical??
>
>Thanks,
>Doug Claar
>HP Computer Systems Division
>UUCP: mcvax!decvax!hplabs!hpda!dclaar -or- ucbvax!hpda!dclaar
>ARPA: dclaar%hpda@hplabs.HP.COM



It's quite simple.  Since a laser beam is just a light source, you use
high transmission (99.9%+) optics for focusing your beam to what ever
radius you want.  You steer a laser beam with high reflectivity (laser
quality ) mirrors.  For some applications prisms or corner cubes are used.
Prisms and some corner cubes use total internal reflection for bending a
beam exactly 90 degrees.  All of these optics must be of extremely high
quality in order not to lose the coherency (spatial or temporal) of the 
laser beam.

Marcell Stoer
Centre for Molecular Beams and Laser Chemistry