Photonic switch a few wavelengths of light

A team of researchers has developed what it claims is one of the tiniest optical switches ever made — about one tenth of the size of a human hair.

The technology may eventually be used in small consumer devices that connect every home or office to an optical fibre and supply high-data rates, including television on demand.

The scientists — based at the School of Physics & Astronomy at the University of St Andrews, Scotland — have used photonic crystal technology to reduce the size of the switch to only a few wavelengths of light.

They are led by Prof Krauss, who explained:

“The switch is aimed at applications in telecommunications, where we foresee its use in routing optical signals. The idea of using fibre in the home or office requires small optical circuits that operate with low power.

“When these can be mass-produced in a cost-effective way, it helps to keep the cost of the products down. At the moment, optical switches tend to be millimetres in size. It is difficult to state which is the smallest optical switch ever made, but this is certainly one of them,” he added.

By focusing on silicon as the material platform, the photonic devices developed by the group can be mass-produced in a similar way to computer chips used for the microelectronics industry and integrated with electronic circuitry on the same chip.

The group aims to address the increasing need for optical components at all levels of the communications network that carries the ever-increasing flow of data over the internet.

The work is part of the British Silicon Photonics project, a consortium led by Surrey University that recently received a funding boost from Britain's Engineering and Physical Sciences Research Council, with £1.4 m awarded to St Andrews University.

There is a growing need for optical components in telecoms networks to support increasing user demands on the internet. Therefore, before too long, fibre optics will enter our homes — and that makes more affordable optical switches essential.

The School of Physics & Astronomy is recognised as a world-leading research establishment. With a growing academic research base, covering a diverse range of subject areas, the school offers a unique academic environment.

Reflecting the continued success of its research groups, physics teaching at St Andrews has been officially graded as excellent, with inspectors commenting on its 'outstanding' teaching environment.