The key to the approach is a gold sphere just 50 nanometers in diameter. A Rice University team led by Peter Nordlander and Naomi Halas has shown that such a sphere, when positioned within a few nanometers of a thin gold film, will behave like a tiny antenna that can transmit or receive light. Light of specific wavelengths excites particles called plasmons inside the nanosphere. This in turn induces a "plasmon wave" in the gold film, which could be converted back into light when it reaches another nanosphere.
Variations on the gold nanosphere might make it possible to exploit materials already used in computer chips, such as copper and aluminum, as superfast optical interconnects, says Mark Brongersma, a materials scientist at Stanford University. A light wave encoding data would hit a metal nanosphere, generating a plasmon wave that would travel through a metal strip or wire, carrying the data with it.