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From: brucec%phoebus.labs.tek.com@RELAY.CS.NET (Bruce Cohen;;50-662;LP=A;)
Newsgroups: sci.virtual-worlds
Subject: Re: optical gyros
Message-ID: <11925@milton.u.washington.edu>
Date: 29 Nov 90 01:14:45 GMT
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In article <11836@milton.u.washington.edu> 23r@sage.cc.purdue.edu (John Dormer) 
writes:
> 
>   I recall from a couple years back, when I was very interested in laser
> devices, that Hughes Aircraft had made optical (laser-ring) gyroscopes. The
> ones for military aircraft could detect >extremely< small rotations...measured
> in degrees per minute, and they were decimal numbers to boot.
>   I don't know if anyone has made smaller versions of this technology, but it
> should be feasable. The Hughes ring was about $200k I think...a bit expensive,
> but I remember reading somewhere about a company who had sucessfully made a
> solid version of the ring-gyroscope (Hughes used mirrors on a stout frame
> about 10" across [from the photos]), which used beveled, mirrored faces on
> the outside of some kind of crystal material (optical glass probably). The
> availability of IR laser diodes should bring the price down quite a bit.

A smaller, more rugged, and potentially cheaper design is to use an optical
fiber as a light path for the gyro.  I don't know about commercial sources
for such things, but I've seen photos of lab units whose sensitivity is
dependent on the length of the fiber.  The fibers are quite thin, so lots
of meters of fiber can be coiled neatly into a small volume.
--
------------------------------------------------------------------------
Speaker-to-managers, aka
Bruce Cohen, Computer Research Lab        email: brucec@tekchips.labs.tek.com
Tektronix Laboratories, Tektronix, Inc.                phone: (503)627-5241
M/S 50-662, P.O. Box 500, Beaverton, OR  97077