The last few months of 2004 saw notable progress toward the challenging goal of all-optical data switching. By eliminating costly and time-consuming conversion between electronic and photonic signaling, all-optical hardware promises data-handling rates of 100 terabits per second before the end of this decade.
Current optical switches include Lucent Technologies WaveStar LambdaRouter, a microelectromechanical system using tiltable mirrors about the size of the eye in a sewing needle. Even these, however, look clumsy compared with the fully photonic approaches being explored by researchers including Michal Lipson, assistant professor in the Department of Electrical and Computer Engineering at Cornell University.
As reported late last year in the journal Nature, Lipsons Cornell Nanophotonics Group has demonstrated a device in which one light signal controls the passage of another, using resonance effects in a silicon ring only 10 microns across.
Other work in photonic switching during 2004 included progress toward building three-dimensional photonic crystals, now being independently developed by teams at both MIT and Kyoto University, that emit and control light emissions and properties such as the polarization of the wave, enabling precise routing of signals without mechanical moving parts.
MITs process may yield communication components in two to three years, while Kyotos process may yield more fully integrated components in five to 10 years.