Path: utzoo!utgpu!cunews!cognos!geovision!gd
From: gd@geovision.gvc.com (Gord Deinstadt)
Newsgroups: comp.arch
Subject: Re: Optical Interconnect
Message-ID: <1489@geovision.gvc.com>
Date: 15 Apr 91 16:07:20 GMT
References: <12618@pt.cs.cmu.edu> <510001@hpsciz.sc.hp.com> <3326@crdos1.crd.ge.COM>
Organization: GeoVision Corp., Ottawa, Ontario
Lines: 16

davidsen@crdos1.crd.ge.COM (Wm E Davidsen Jr) writes:
>In article <510001@hpsciz.sc.hp.com> peng@hpsciz.sc.hp.com (Peng Lee)
 [suggests using external lasers perpendicular to a stack of chips for
  interconnect:]
>  Why would you do this rather than use an IR LED on the sender chip,
>avoiding having to pipe the light through multiple chips?

I'm not sure about LEDs, but I know it's hard to make a laser that emits
perpendicular to the surface of the chip - most are edge-emitters.  But
you could put mirrors or light guides along one edge of the chips.  Certainly
the gain in speed vs LCD switches would be worthwhile.  If you really need
the 2-d interconnect, you could also interleave the chips with
electroluminescent emitters, and perhaps use lithium niobate (or some such)
modulators for higher speed.
--
Gord Deinstadt  gdeinstadt@geovision.UUCP