Negative index metamaterials for visible-light optics.

Recent advances in nanofabrication allow one to create new composite metamaterials with constituents of different forms and sizes down to nanoscales. These materials have attracted considerable interest as they offer a possibility to realise a negative index of refraction with many surprising properties important for optics, communication and electronics. Nanocomposite metamaterials also promise a whole variety of amazing applications, e.g., a perfect lens producing a perfect image of an object, a nanolens focusing light into a sub-wavelength spot, a nanolaser amplifying near-fields through a stimulated emission of radiation.We have recently designed and nanofabricated the first artificial metamaterial with negative index of refraction at visible-light frequencies. In this material the high frequency magnetic response is produced by collective oscillations of electrons in coupled pairs of gold nanopillars. We have confirmed the extraordinary properties of the new media by observing the impedance matching effect (previously known only for radio-wave frequencies) and a large enhancement of the electric field in the immediate proximity of individual nanomolecules. It was only the relatively large dissipation and small thickness of the fabricated nanocomposites that did not allow us to observe the effect of negative refraction.This proposal aims to expand our initial findings into a viable research programme based on our current competitive advantage in exploration of negative index metamaterials. We will design composite nanomaterials made from coupled metallic nanoelements with stronger magnetic and electric response at frequencies of visible light. The main focus of our research will be engineering of negative index materials with low dissipation, which is a key element to developing new optical devices including the perfect lens. We plan to fabricate new optical composite nanomaterials, study their extraordinary electromagnetic properties and assess some of their applications, which we believe are the most promising and within our expertise (feasibility study of a perfect lens and a nanolens, biosensing, etc.).