to the Website of a Multidisciplina- ry University Research Initiative (MURI) Project "Tunable and Re- configurable Optical Negative-Index Materials with Low Losses".

The focus of this project is NIMs - Negative-Index Materials - a novel class of engineered materials with very unusual and potentially very valuable optical properties. The most surprising characteristic of these materials is their negative refractive index, hence the name - NIMs.

The refractive index gives the factor by which the phase velocity of electromagnetic waves propa- gating in a material is decreased relative to its magnitude in vacuum. One of the manifestations of nega- tivity of the refractive index of NIMs is the fact that the phase velocity of electromagnetic waves in them is directed against the flow of energy.

There are no naturally-occurring NIMs, as far as we know, but certain specially designed artificial materials (metamaterials: see an example in the column on the right) can possess the property of negative refraction. Metamaterials offer unique physical properties and can enable functionality of devices based on them unattainable with naturally-existing materials.

In this project, we will study NIMs for the Optical frequency range (ONIMs), and we will focus on eli- minating light energy losses in ONIMs and developing novel ONIM-based applications.

The material losses will be over- come by compensation with ampli- fication provided by gain inclusions, elimination by using passive low-loss components, or a combination of both.

New applications are exemplified by optical nanoscale lithography, imaging, and sensing utilizing an ONIM-based tunable and recon- figurable superlens.