Optical materials go designer

Advances in fabrication technologies could one day lead to superlenses and other designer optical materials.

Scientists at Iowa State University and at Karlsruhe Institute of Technology in Germany are studying exotic man-made materials designed to deliver optical properties not found in nature. Their work appears in Science, Vol. 330, No. 6011, pp. 1633-1634 (2010).

Unlike natural materials, metamaterials can refract light to the left, or at a negative angle. This allows scientists to control light similar to the way they use semiconductors to control electricity.

The discovery could allow scientists to use metamaterials to develop a flat superlens that can operate in the visible light spectrum. Offering superior resolution over conventional technology, the lens would be able to capture details much smaller than one wavelength of light, which could result in the ability to see inside a human cell or to observe DNA.

The challenges, however, will take additional research and development to overcome. Because the structures must be tiny, they are difficult and expensive to produce. Optical metamaterials also absorb light, which would make it difficult to create metamaterial superlenses.

The scientists’ experiments have proved hopeful. They found that optical metamaterials can operate within the visible light spectrum, that 3-D optical metamaterials can be produced and that light loss in metamaterials can be reduced. All three of these properties, when wrapped together into one new material, could provide the qualities necessary for an ideal optical metamaterial suitable for materials and biomedical applications.