The creation of a lens that can image light from an entire hemisphere onto a flat surface is reported online this week in Nature Materials. The finding could in future prove useful in the development of detectors and cameras.
Optical lenses, by design, can only magnify light coming in from one direction. However, through careful engineering of light propagation through an artificial medium ― a metamaterial ― this restriction has been overcome. Metamaterials allow the complete and deliberate control of light propagation, and therefore considerably expand the capabilities of optical instruments beyond what is possible with glasses.
Nathan Kundtz and David Smith created a metamaterial lens that captures light from angles up to 180° and projects it onto a surface. Combined with a camera chip attached to this flat surface, such a lens can image and transmit an entire hemisphere with a single camera shot. The present lens is designed to work in the microwave region, although the design can in future be scaled down so as to be used with visible light.