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Slow Light, Fast Money Commentary | |||||
OPTICAL TRANSISTORS Last week, a Danish team working at Harvard and the Rowland Institute in Cambridge reduced the speed of light to 38 mph which, of course, is the aspect of their work that got the consumer media all in a tizzy. Not that that part isnt interesting, of course, but much more interesting was how it was done, and what it means. First, having cooled a cloud of sodium atoms to about 50 billionths of a degree above absolute zero, they shot a laser beam into the cloud at exactly the resonant frequency of the atoms. Because this was the resonant frequency, the beam was completely absorbed (the cloud became opaque to the beam), and one can surmise that the energy thus absorbed was converted to a higher energy state of the sodium although not likely to have shown up as kinetic energy (heat). (Note: lasers have long been used to cool and homogenize the kinetic energy of such clouds by slowing fast oncoming atoms and speeding slow departing atoms.) Now jump for a moment to classical quantum mechanics: light cannot interact with itself, since all light waves are just superimposed on each other. Not much use in computers. But this week the Danes did something different: by tuning the first laser to the resonant frequency of the atoms, and then shooting in a second tuned laser at a different frequency, the second beam actually interacted with the resonant soup. Result: the second beam passed about 25 percent of its energy through the soup, at a speed of 38 miles per hour. This is similar to using one stream of electrons to control the flow of another, which happens to be the basis for all modern transistors. Cocktail Party Summary: using light/matter resonance, optical transistors (and computers) are a step closer to reality.
JAVA GOES FREE ER, OPEN
CALIFORNIA: A Y2K MINIVERSE
Mark Anderson is the president of Technology Alliance Partners, which provides consulting to telecom and computing firms. The Next Files, excerpted from Andersons Strategic News Service newsletter, appears every Monday. Copyright 1999 Strategic News Service. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
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S U M M A R Y Light slows down, Java goes open source (for a fee) and California admits its not up to speed on Y2K.
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