A transmission medium with a negative index of refractions would enable a flat planar lens to focus light to precisions that are smaller than the wavelength of the light itself. With tunable versions of such photonic materials now being rushed into prototypes by labs worldwide, it is conceivable that not only could a "perfect" lens be created but that known electron effects could be translated into photonic operations to create sensors that could detect a single molecule. "Conventional lenses cannot focus light in an area smaller than the wavelength of the light, but with our nanomaterials you can focus light down much smaller than its own wavelength," said Shalaev. "These metallic nanostructures might even be able to detect a single molecule of a substance, which will never be possible for conventional optics."All materials have two fundamental electromagnetic parameters: permeability and permittivity, which respectively measure the capacities of a medium to form magnetic and electrical fields. The values of those parameters produce the characteristic bending of a light beam when it travels from one medium into another. In addition, since both parameters are always positive in nature, the electric and magnetic vector field components are directed according to the "right-hand rule," which can be represented by pointing the index finger of the right hand in the direction of propagation. The thumb and middle finger are then oriented at right angles to the index finger, showing the field vector directions.
http://www.eet.com/at/news/OEG20020826S0041
