Researchers from Australia's Swinburne University and Germany's Friedrich-Alexander Universität Erlangen-Nürnberg have developed artificial crystals with unique optical properties that could lead to advances in quantum computing and telecommunications. Their inspiration? The glorious green wings of the Callophyrs Rubi butterfly.

To develop the next generation of optical chips, scientists require the ability to control light at the nanoscale. Beamsplitters that direct the flow of light based on linear polarization already exist, but similar devices based on circular polarization would be an important component for many optical chip designs. Until now such a device has not existed.

The wings of the Callophyrs Rubi butterfly contain an array of interconnected, nano-scale coiled springs. It is this construct that gives the Callophrys Rubi its brilliant green color, and it has supplied a blueprint for developing the new photonic crystal.

"The photonic crystal beamsplitter that we made is a fundamental optical component used to control polarized light," explains Dr Mark Turner from Swinburne University. "Specifically what makes our device unique is its ability to directly work with circular polarization at a microscopic scale."

Scientists used 3D laser nanotechnology to build the photonic crystal device using the butterfly's wings as the design concept. The result is a microscopic prism that contains in excess of 750,000 polymer nanorods. When light is focused onto this beamsplitter it reflects off, or is transmitted through, depending on its polarization.

"The fact that the device is so tiny (less than the width of the human hair) is promising that many of these microscopic devices could be packaged into a small 'optical chip,' just like an electronic chip," says Dr Turner. "This step is essential for transferring many laboratory based applications into a real world product.

Aside from applications in quantum teleportation and quantum optical computing where circular polarization states can be used to perform quantum operations, the new capabilities offered by the photonic crystal beamsplitter could also lead to improved internet bandwidth and chemical detection.

"Biological and chemical detection often measure the polarization of a sample to deduce what the sample is," says Dr Turner. "Circular polarization can provide details on the symmetry of the sample and is used to detect certain complex biomolecules."

The research is published in the journal Nature Photonics.