Faster internet comes to light

An international team of researchers has developed and tested optical molecules which could be used in components to make the next generation of the internet faster.

The team from Washington State University (WSU), the University of Leuven and the ChineseAcademy of Science produced organic molecules known as chromophores, which interact more strongly with light than any molecules ever tested. That makes them, or other molecules designed along the same principles, prime candidates for use in optical technologies such as optical switches, internet connections, optical memory systems and holograms.

The molecules were synthesised by chemists in China, evaluated according to theoretical calculations by a physicist at WSU and tested for their actual optical properties by chemists in Belgium.

‘To our great excitement, the molecules performed better than any other molecules ever measured,’ said WSU physicist Mark Kuzyk.

In 1999, Kuzyk discovered a fundamental limit to how strongly light can interact with matter. He went on to show that all molecules examined at that time fell far short of the limit. The newly developed molecules break through this long-standing ceiling and are intrinsically 50 per cent more efficient at converting light energy to a useable form than any previously discovered.

The new design parameters call for a molecular structure that increases a property known as the ‘intrinsic hyperpolarisability,’ which reflects how readily electrons in the molecule deform when the molecule mediates the merger of two photons into one, an action which is the basis of an optical switch.

Kuzyk said that for use in optical switches or other products, the molecules would probably be embedded in a clear polymer that would provide structural assets such as the ability to be formed into a thin film or into fibres, moulded into other shapes or used to coat circuits or chips.