Nanoribbons channel light

In theory, computer chips that use light rather than electricity to pass signals through circuits would be considerably faster than today's electronics.

One challenge in making optical computer chips is finding a way to guide light through minuscule channels between circuits.

Researchers from the University of California at Berkeley and Lawrence Berkeley National Laboratory have made crystalline oxide nanoribbons that are capable of carrying light and that are flexible enough to form the patterns needed to carry out logic operations.

The nanoribbons could eventually be used to carry out chip-based optical computing and to enable tiny chemical and biological sensors.

The nanoribbons range from 15 to 2,000 nanometers wide by 5 to 1,000 nanometers thick and are as long as 1.5 millimeters. Nanoribbons that are several hundred nanometers wide are capable of channeling visible and ultraviolet light even though they are narrower than the wavelengths of the light. A nanometer is one millionth of a millimeter.

The researchers also found that the ribbons do not need to be connected end-to-end in order to transmit light from one to another. They found that the most efficient way to connect nanoribbons was simply overlapping two ends. Molecular electrostatic forces held the ends together.

The researchers have also coupled one of the nanoribbons to a light-emitting nanowire. There are working on coupling nanoribbons with nanowire lasers and photodetectors.

Nanowire photonic circuitry could be used practically in 10 years, according to the researchers. The work appeared in the August 26, 2004 issue of Science.