Bulk photonic metamaterial with hyperbolic dispersion

We have demonstrated the thickest bulk photonic metamaterial reported in the literature based on an Ag-filled alumina membrane. The material is highly anisotropic with hyperbolic dispersion at lambda>0.84 mu m. The refraction of light in the direction expected of isotropic media with n < 1 has been experimentally demonstrated at lambda=632.8 nm. This makes the material potentially suitable for a variety of applications ranging from subdiffraction imaging to optical cloaking.