55 nanotimes News in Brief

Image: Indefinite optical cavities feature a hyperboloid iso-frequency contour that supports ultrahigh optical refractive indices. This cross-section shows the IFC (bronze curves) for a silver/germanium metamaterial with yellow circles representing cavity wave vectors and the green circle representing the light cone of air. © Xiang Zhang group

This schematic shows (a) an indefinite metamaterial structure with alternating silver and germanium multilayers; and (b) its iso-frequency contour of light wave vectors with negative refractions along the x- and y-directions, and positive along the z-direction. © Xiang Zhang group

Electron micrograph showing arrays of indefinite optical cavities comprised of silver/germanium multilayers. © Xiang Zhang group