Light Can be Twisted With a Newly Developed Material

Scientists at the Australian National University have developed a material that can twist light itself. This unlike regular material possesses extraordinary properties; it is the latest in a new breed of materials called metamaterial. The findings were published in Nature Communications.

Mingkai Liu, a PhD student at the ANU Research School of Physics and Engineering (RSPE) explained that this new material can rotate lights polarisation, orders of magnitude more strongly than natural materials and they can switch the effect on and off directly with light.

"The idea came to me when I found a piece of wire in my washing one day," said Liu, leading the team to create these artificial materials, which is the latest step in the development of photonics, the faster, and more compact and less carbon-hungry successor to electronics.

A pattern of tiny metal shapes called meta atoms were used to form the meta materials. A pair of C shaped meta atoms, suspended one on top of the other were used to twist light. The atoms were held together by a fine wire. When light was shined onto the pair, the top one rotated and made the system asymmetric.

"Because light affects the symmetry of our system, you can tune your material's response simply by shining a light beam on it. Tunability of a metamaterial is an important step towards building devices based on these artificial materials," said Liu.

Electronics are estimated to account for about two percent of the global carbon emissions, this can be significantly reduced by photonics. The new release states that the light carried by fiber optics has replaced electricity for carrying signals over long distances. These latest findings could help further photonics, which could be a boon for the environment and for consumers.

Researchers said, "The next step is to develop photonic analogues of electronic computer chips, by actively controlling the properties of light, such as its polarization" It is due to the asymmetry of a molecule in a material that it can rotate polarisation.

Dr David Powell, from RSPE, suggested that the remarkable properties of this artificial material might first be put to use in the budding photonics industry. "It's another completely new tool in the toolbox for processing light. Thin slices of these materials can replace bulky collections of lenses and mirrors. This miniaturisation could lead to the creation of more compact opto-electronic devices, such as a light-based version of the electronic transistor," said Powell.

Lui explained that the high responsiveness of the system comes because it is very easy to make something hanging rotate.