Bath physicists use photonic crystal fiber to more efficiently create attosecond pulses

November 20, 2007, Bath, England--This week, the journal Science describes research by a physics team at the University of Bath led by Fetah Benabid that uses a special hollow-core photonic crystal fiber to send out pulses of light that last only an attosecond. The research has opened the door to what could prove to be a new sub-branch of photonics, the science of light guidance and trapping.

These pulses are so brief that they allow researchers to more accurately measure the movement of sub-atomic particles such as the electron, the tiny negatively-charged entity which moves outside the nucleus of an atom. Attosecond technology may throw light, literally, upon the strange quantum world where such particles have no definite position, only probable locations.

To make attosecond pulses, researchers create a broad spectrum of light from visible wavelengths to x-rays through an inert gas. This normally requires a gigawatt of power, which puts the technique beyond any commercial or industrial use. But Benabid's team used a photonic crystal fiber (PCF), which traps light and the gas together in an efficient way. Until now the spectrum produced by PCF has been too narrow for use in attosecond technology, but the team have now produced a broad spectrum, using what is called a Kagomé lattice, using about a millionth of the power used by non-PCF methods.

"This new way of using photonic crystal fibre has meant that the goal of attosecond technology is much closer," said Benabid. "The greatly reduced cost and size of producing these phenomenally short and powerful pulses makes exploring matter at an even smaller detail a realistic prospect."
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For more information, visit www.bath.ac.uk.