Experimental demonstration of negative index of refraction

We introduce an improved and simplified structure made of periodic arrays of pairs of H-shaped metallic wires that offer a potentially simpler approach in building negative-index materials. Using simulations and microwave experiments, we have investigated the negative-index $n$ properties of these structures. We have measured experimentally both the transmittance and the reflectance properties and found unambiguously that a negative refractive index with $\mathrm{Re}\left(n\right)<0$ and $\mathrm{Im}\left(n\right)<\mathrm{Re}\left(n\right)$ . The same is true for $\epsilon$ and $\mu$ . Our results show that H-shaped wire pairs can be used very effectively in producing materials with negative refractive indices.