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Status: RO Subject: Optical analog computing? From: Rohit Khare <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] Sender: [EMAIL PROTECTED] Date: Tue, 1 Oct 2002 10:54:02 -0700 I'm at a speech by Terry Essex, CTO of Essex Corp. He worked on optical computing at the NSA for a long time. "the first computer to crack enigma was optical" "the first synthetic-aperture-radar processor was optical" "but all these early successes were classified -- 100 to 200 projects, and I probably know of less than half." --> Do these claims compute?! is this really a secret history, or does this mean holography, of am I just completely out of the loop?1 Optical info is a complex-valued wave (spatial frequency, amplitude and phase) lenses, refractions, and interference are the computational operators. (add, copy, multiply, fft, correlation, convolution) of 1D and 2D arrays and, of course, massively parallel by default. and, of course, allows free-space interconnects. Here's a commercialized effort from israel: a "space integrating vector-matric multiplier" [ A ] B = [ C ] laser-> 512-gate modulator -> spread over 2D "256 Teraflop equivalent" for one multiply per nanosecond. Unclassified example: acousto-optic spectrometer, 500 Gflops equivalent (for 12 watts!) doing continuous FFTs. Launched in 1998 on a 2-year mission. Submillimeter wave observatory. Of course, the rest of the talk is about the promise of moving from optoelectronic to all-optical processors (on all-optical nets & with optical encryption, & so on). very compact supercomputing, made much cheaper by telecom industry's investment in opto components. Key is to follow the wideband signal processing applications, not "balancing your checkbook" applications. displaying MRIs in 3-D in realtime (you can collect, but not yet display in r/t). [ps: there was a great piece on developing portable (handheld!) passive MRI devices in a recent Caltech alumni magazine report. article attached in next email] 1.6 Tflop imager for mine-detection for ground-penetrating radar in 3D SAR is a new commercial application --- end forwarded text -- ----------------- R. A. Hettinga <mailto: [EMAIL PROTECTED]> The Internet Bearer Underwriting Corporation <http://www.ibuc.com/> 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire' --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]
