Tiny optical cable comes to light

Physicists at Boston College have beamed visible light through the narrowest nanoscopic cable to date, an achievement they anticipate will lead to advances in solar power and optical computing.

The discovery defies a key principle that holds that light cannot pass through a hole much smaller than its wavelength. The BC team forced visible light, which has a wavelength of between 380-750 nanometres, to travel down a cable whose diameter is smaller than even the low end of that range.

The researchers said their achievement opens the door to a wide array of new technologies, from high-efficiency, inexpensive solar cells to microscopic light-based switching devices for use in optical computing. It could even be used to help some blind people see.

The advance builds upon the researchers' 2004 invention of a microscopic antenna that captures visible light in much the same way radio antennae capture radio. This time they have designed and fabricated a tiny version of a coaxial cable.