http://www.forbes.com/business/forbes/2005/0411/068.html

Teaching silicon new photonic tricks promises a huge boost in getting data out of a computer

In his lab at Sun Microsystems' San Diego Physical Sciences Center, Ashok Krishnamoorthy is surrounded by big numbers: looming powerful computers that can crank through a trillion operations per second. But what commands his attention these days is something very small: a prototype silicon chip, only a few millimeters on a side, that works like a magic gateway between muscle-bound computers.

Although still a hatchling, this so-called silicon photonic chip, devised by a Carlsbad, Calif. startup called Luxtera, could mark the beginning of a new Internet era when computers will be able to tap into huge reserves of data, no matter where they are situated, as easily as they now retrieve data from their own hard drives. "It will mean that distance truly won't matter anymore," says Arno Penzias, a Nobel laureate and one of Luxtera's venture backers. "Wherever you are, you can share in all the world's information."

Big promises come in small packages. Luxtera's chip is neatly hidden inside a component that looks like a gold-covered mint wafer. Metal pins along three sides both secure the piece to a circuit board and deliver streams of bits to the silicon device. On the fourth side of the component is a plug that resembles a telephone jack. Krishnamoorthy slides a bundle of fiber-optic threads into the plug. One thread is attached to a laser.

As the pins deliver bits sent from another computer, the laser pumps a steady stream of light into the chip. Inside, a modulator works like a tiny shutter, imprinting the bits onto the incoming laser light. The light signals do a victory lap in the device, then head out on a path that runs parallel to the one they came in on. The signals spill onto an optical fiber, then travel another 20 meters before reaching a detector, a chip that transforms the light signals back into electrical ones. "We've been working with Luxtera for almost a year now," says Krishnamoorthy. "I have personally tested the modulators to 10 gigabits a second." That's fast enough to send a DVD movie in four seconds.