PHOTONICS PICKS UP WHERE ELECTRONICS LEAVES OFF
A major technological transformation -- potentially as significant as the electronics revolution of the 20th century -- is creeping up on a largely unsuspecting world.
Light, in the form of tiny, weightless particles called photons, is on its way to succeeding electrons as the high-tech workhorse of the 21st century, scientists say.
Practical applications of the coming photonics revolution are still a ways off, but researchers offer the prospect of much faster communications, more powerful computers, sharper display screens, more effective ways to convert sunlight to energy and many other benefits.
For example, the Pentagon is experimenting with photonics for future military technologies, such as night vision, early warning sensors and automatic target recognition, according to Anthony Tether, director of the Defense Advanced Research Projects Agency.
By shooting photons through the air instead of pushing electrons along wires, information networks can move data at trillions of bits per second instead of millions or billions, as networks do now. In addition, Tether said, photonic links can provide a thousandfold in savings of size and power needs.
Photons and electrons are very different creatures. Photons are the smallest carriers of energy. They make up the electromagnetic spectrum, an array of forces that includes X-rays and ultraviolet, infrared and radio waves, as well as visible light.
Electrons, in contrast, are a basic component of matter. They are an essential part of every atom and the principal tool of the information age. But they are beginning to run into size and speed limits in some fields, such as computing and telecommunications.
News source: SiliconValley.com
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A major technological transformation -- potentially as significant as the electronics revolution of the 20th century -- is creeping up on a largely unsuspecting world.
Light, in the form of tiny, weightless particles called photons, is on its way to succeeding electrons as the high-tech workhorse of the 21st century, scientists say.
Practical applications of the coming photonics revolution are still a ways off, but researchers offer the prospect of much faster communications, more powerful computers, sharper display screens, more effective ways to convert sunlight to energy and many other benefits.
For example, the Pentagon is experimenting with photonics for future military technologies, such as night vision, early warning sensors and automatic target recognition, according to Anthony Tether, director of the Defense Advanced Research Projects Agency.
By shooting photons through the air instead of pushing electrons along wires, information networks can move data at trillions of bits per second instead of millions or billions, as networks do now. In addition, Tether said, photonic links can provide a thousandfold in savings of size and power needs.
Photons and electrons are very different creatures. Photons are the smallest carriers of energy. They make up the electromagnetic spectrum, an array of forces that includes X-rays and ultraviolet, infrared and radio waves, as well as visible light.
Electrons, in contrast, are a basic component of matter. They are an essential part of every atom and the principal tool of the information age. But they are beginning to run into size and speed limits in some fields, such as computing and telecommunications.
News source: SiliconValley.com View: The Full StoryGradual takeover
''You'll see enormous advances in optical components and devices,'' he said. ''Miniaturization will lead to many-orders-of-magnitude increases in performance. You can do a lot more in a lot less real estate.''
In laboratories around the world, physicists and optical engineers are practicing ingenious tricks to control light. They have learned how to make photons follow straight paths, split, rejoin, turn sharp corners, change speed, even stop in their tracks.
Lene Hau, an optical physicist at Harvard University, in Cambridge, Mass., has slowed a beam of light to the sluggish pace of about one mile per hour, a tremendous drop from its normal speed of 186,000 miles per second. Peter Zoller, a physicist at the University of Innsbruck in Austria, has brought a bunch of photons to a complete stop, then set them free to zoom off again at their original pace.
''It's thrilling to think we can control light,'' Hau said, adding that many research groups ''all over the world are pouring into the field.''
According to Hau, scientists put the brakes on photons by slamming them into a cloud of sodium atoms that have been cooled to almost 460 degrees below zero Fahrenheit.
''When the light enters the cloud, it slows down and compresses like a concertina,'' she said. ''When it exits the cloud, it expands and goes on its way, exactly like it was before.''
Unimaginable benefits
The first commercial beneficiaries of the photonics research probably will be computing and telecommunications. They stand to benefit from the blinding speed and minute size of particles of light.
Computer scientists have dreamed for years of being able to compute with photons instead of electrons. Current technology is nearing its physical limit as computer-makers cram more and more transistors onto silicon chips.
To get around the limits on the chips' capacity, government, academic and private researchers are turning to photonics. Photonic crystals -- tiny cages or honeycombs constructed of silicon -- trap, guide and switch light much the way semiconductors manipulate electrons in today's computers.
''The optical world will slowly creep its way into the electronics world by replacing devices on a chip,'' said Axel Scherer, an electrical engineer at the California Institute of Technology in Pasadena.
In the communications field, most long-distance telephone and computer networks already transmit digital information -- zeroes and ones -- in the form of pulses of light racing along optical fibers.
Overcoming drawbacks
In contrast, researchers say future optical-communications systems will use fibers composed of tiny mirrors that direct photons down a desired path without using wires.
Yoel Fink, a physics professor at MIT, invented ''photonic fibers,'' which he said can deliver up to 1,000 times more photons than today's fiber-optic cables. Fink and colleagues started a company, Omniguide Communications, based in Pasadena, to commercialize their invention.
At least a dozen other firms are entering the field, despite the slump in high-technology companies that includes the Jan. 28 bankruptcy of Global Crossing, a big fiber-optics communications company.
Major corporations such as IBM, Lucent and Agilent Technologies are developing ''photonic switches,'' systems of mirrors that redirect photons like freight cars in a railroad yard.
Scherer said photonic crystals can be manufactured at a reasonable cost using the same basic technology as today's silicon-chip factories. He predicted that such devices ''will be ready for commercial applications very soon.''
''Right now, it's mostly baby steps in the lab,'' said Mikhail Lukin, a Harvard physicist. ''But there is hope for something practical someday.''
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