IBM slows down light on a silicon chip

IBM researchers have created a tiny device that could lead to the use of light in place of electricity in the connection of electronic components, the company announced today. This technology ha sthe potential to bring "vast improvements in the performance of computers and other electronic systems," IBM claims.

The firm’s scientists were able to slow light down to less than 1/300th of its usual speed (down to about 620 miles per second) by directing it down a carefully designed channel of perforated silicon called a "photonic crystal waveguide." The device allows the light’s speed to be varied over a wide range by applying an electrical voltage to the waveguide, IBM said. While slowing down light under laboratory conditions is nothing new, the company claimsthat actively controlling the light’s speed on a silicon chip and using standard silicon with standard micro- and nanoelectronic fabrication technology, is a first.

The device’s small size, use of standard semiconductor materials, and ability to more closely control this "slow light" could make the technology useful for building ultra-compact optical communications circuits that are practical for integration into computer systems.