Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!sundc!hqda-ai!cos!smith From: smith@COS.COM (Steve Smith) Newsgroups: comp.arch Subject: Re: how fast could disks be (Mach 1) Message-ID: <406@cos.COM> Date: Thu, 20-Aug-87 16:39:59 EDT Article-I.D.: cos.406 Posted: Thu Aug 20 16:39:59 1987 Date-Received: Sat, 22-Aug-87 11:53:09 EDT References: <12191@amdahl.amdahl.com> <1189@k.gp.cs.cmu.edu> <1075@vlsi.cs.cmu.edu> Reply-To: smith@cos.UUCP (Steve Smith) Organization: Corporation for Open Systems, McLean, VA Lines: 31 Keywords: laser disk scan electro optic In article <1075@vlsi.cs.cmu.edu> gwu@vlsi.cs.cmu.edu (George Wu) writes: > There's been all this talk about gaining faster mass storage with >parallel operations, and more recently, optical disks. But it seems to me that >a limiting factor are the mechanical parts, which must physically move. Even >using a scanning laser beam to read optical disks, a mirror must be >manipulated, unless someone has found a way to bend light. Relativity anybody? There's a gizmo called an electro optic modulator that works on nonlinear optical effects in crystals. They will "bend light" and do lots of other tricks with no moving parts. They are also very fast. I don't have any current information, but any of the laser industry rags should have lots of ads. Check Electro Optic Systems Design, Laser Focus, etc. From what I remember on these things, there are some problems: 1. Deflection angles are VERY small (~1 degree) 2. They're VERY expensive 3. They require very fast switching of high voltages This information isn't current; I hope they've improved things. Another system that is cheaper but not so fast is called an accousto (sp?) optic modulator. It uses ultrasonic standing waves in a crystal to do its work. Again, I have no current info. -- __ -- Steve / / \ / "Truth is stranger than S. G. Smith I \ O | _ O \ I fiction because fiction smith@cos.com / \__/ / has to make sense."