A newly discovered material that causes light to refract "backwards" has the potential to improve the efficiency of optical networking devices, researchers reported today.

Refraction always bends light one way. A new metamaterial crafted from alternating layers of semiconductors (indium-gallium-arsenic and aluminium-indium-arsenic) acts as a single lens that refracts light in the opposite direction.

The material was developed primarily at the US National Science Foundation's Mid-Infrared Technologies for Health and the Environment Engineering Research Center and the Princeton Center for Complex Materials.

"Refraction is the reason that lenses have to be curved, a trait that limits image resolution," said the National Science Foundation.

"With the new metamaterial, flat lenses are possible, theoretically allowing microscopes to capture images of objects as small as a strand of DNA.

"The current metamaterial lens works with infrared light, but the researchers hope the technology will expand to other wavelengths in the future."

Earlier efforts have crafted metamaterials that bend light in a similar way, but this is the first to do so using a 3D structure and a metamaterial comprised entirely of semiconductors.

These traits will prove critical for incorporating the technology into devices such as chemical threat sensors, communications equipment and medical diagnostics tools, according to NSF.