Making light work of photonics

Bath University researchers are using photonic crystal fibre to make attotechnology, which uses pulses of light lasting only a billion billionth of a second, far more efficient.

Attotechnology refers to the ability to send out pulses of light that last only an attosecond, a billion billionth of a second. 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. This property means attosecond technology may find applications in quantum mechanics and computing.

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.

The Bath team, led by Dr Fetah Benabid, used a photonic crystal fibre (pcf), the width of a human hair, which traps light and the gas together in an efficient way. Until now the spectrum produced by photonic crystal fibre 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.’