Our work is a confirmation of a previous discovery, using a new methodology. The first demonstration of a NIM (Shelby et al, Science) generated a lot of excitement. However, in the ensuing two years, there were no experimental followups and several theory papers questioning the original result. Our work, along with the work of Claudio Parazolli at Boeing, which was published in Physical Review Letters around the same time, confirmed that these materials do have a negative index of refraction. By taking 2D pictures of the field rather than 1D scans, we were able to show that beams were actually propogating in the negative index direction. We also showed preliminary evidence for the flat lensing behavior of these materials.

When light goes from one transparent material to a different transparent material, it bends, and the degree to which it bends depends on the index of refraction. However, for conventional materials, the index is always positive, and the light will never bend further than the line perpendicular to the surface. Negative index materials bend past the normal, "backwards" from positive index materials. Because of this, we can make a lens out of a rectangle of NIM, rather than the curved shapes that are needed to make ordinary lenses. In addition, theory predicts that such a lens could be able to beat the limit on the resolution of conventional lenses.