Surf the Web at the Speed of Light

March 6, 2010— -- Light-speed computing is one step closer to reality.

Scientists from the Massachusetts Institute of Technology have created a new infrared laser made from germanium that operates at room temperature.

The research removes the cryogenic cooling systems previously needed for infrared lasers and could lead to powerful computer chips that operate at the speed of light.

"Using a germanium laser as a light source, you could communicate at very high data rates at very low power," said Jurgen Michel of the Massachusetts Institute of Technology, who developed the new germanium laser. "Eventually you could have the computing power of today's supercomputers inside a laptop."

The creation of a new laser, even one based on germanium, is not newsworthy; more than 15,000 different lasers, some of which use germanium, have been created since the 1950s. What makes this particular germanium laser unique is that it creates an infrared beam at room temperature.

Until now infrared germanium lasers required expensive cryogenic cooling systems to operate. The new germanium laser operates at room temperature.

Light-Speed Laser Is Still Years Away

To create the germanium laser, the scientists take a six-inch, silvery-gray disk of silicon and spray it with a thin film of germanium. These same disks are actually used to produce chips in today's computers.

An electrically powered, room-temperature, infrared laser for laptop computers is still years away, however, cautioned Michel. If and when those laptops do arrive, they will be powerful -- more powerful in fact than even today's supercomputers.

The battery that powers the laptop won't necessarily last any longer, but the power it does hold will make calculations orders of magnitude faster than today.

"We can't keep doing what we are currently doing," said Tom Koch, a scientist at Lehigh University who was familiar with the work but not directly involved with it.

"We need high-density, low-power solutions," said Koch. Computer chips are constantly getting smaller and smaller, but they are approaching the fundamental limits of electron-based computing. Light-based computing is one option to improve the speed and power of computers.

Germanium-Based Optical Computing Is Especially Attractive

Germanium-based optical computing is an especially attractive material for optical computing because it wouldn't require any change to the existing computer chip industry, Koch said. The same machines that use silicon could also use germanium to make future chips.

Despite germanium's advantages, Koch agreed with Michel that years will pass before any consumer devices are made with germanium. Scientifically, however, "this is a really nice result," said Koch.

People have tried to use germanium for an infrared laser for decades without success. The fact that the MIT scientists got the laser working at all is quite impressive, said Koch.