A new material for ultrahigh-resolution microscopes
Source: “Three-dimensional optical metamaterial with a negative refractive index”
Xiang Zhang et al.
Nature 455: 376-379
Results: Researchers have fabricated a material that interacts with near-infrared light in a way that no naturally occurring material does. A prism made from the material has a negative refractive index: that is, it bends light in the direction opposite the one in which ordinary materials bend it.
Why it matters: The prism is the first practical device for redirecting near-infrared light in this way. Devices made from the material could be used in microscopes to produce much sharper images. They could also be used to route light on a microchip or even to render objects invisible to near-infrared wavelengths by directing light around them. Some previous negative-index materials worked only with microwaves; others, which did work with visible or infrared wavelengths, transmitted little light and were so thin that they were difficult to use. The new material is thicker and transmits more light, making it potentially more useful.
Methods: The material is made up of alternating layers of a metal, which conducts electricity, and an insulating material; both are punched with a grid of square holes. This structure gives the material its unusual properties: it creates electrical circuits that respond to the magnetic field of light and change the way light moves through the material.
Next steps: The first applications are likely to be in high-resolution microscopy. The researchers are currently developing methods for making the material in larger quantities