March 22, 2012
Duke University Engineers believe that continued advances in creating ever-more exotic and sophisticated man-made materials will greatly improve their ability to control light at will.
Abstract: Graded-index optics applications are currently limited by the fabrication process to small refractive index contrast or simple geometries. Metamaterials offer a control of the refractive index at the unit cell level, making possible the realization of devices with complex, three-dimensional, large refractive index gradients. However, fabricating such structures for optical wavelengths is challenging because of the dimensions involved. In a paper published in Nature Materials, we demonstrate the fabrication of an hologram operating in the infrared. This device, requiring a two-dimensional refractive index distribution, was fabricated using a microfabrication approach that we developed. This opens the door to exiting applications, particularly if the index gradients is combined with other properties such as anisotropy or nonlinearity.
"In their latest series of experiments, the Duke team demonstrated that a metamaterial construct they developed could create holograms -- like the images seen on credit or bank cards -- in the infrared range of light, something that had not been done before." - Richard Merritt, Pratt School Press Release; Metamaterials will change optics
Stéphane Larouche, research scientist with the Center for Metamaterials and Integrated Plasmonics (CMIP) said “Now, with the advent of metamaterials, we can almost do whatever we want to do with light. In addition to holograms, the approach we developed easily extends to a broad range of optical devices,” Larouche said. "If realized, full three-dimensional capabilities open the door to new devices combining a wide range of properties. Our experiments provide a glimpse of the opportunities available for advanced optical devices based on metamaterials that can support quite complex material properties."
Nature Materials Publication " Infrared metamaterial phase holograms"