Abstract:

We present the blueprint for a novel negative-index metamaterial. This structure is fabricated via three-dimensional two-photon direct laser writing and silver shadow evaporation. The comparison of measured linear optical spectra with theory shows good agreement and reveals a negative real part of the refractive index at around 3.85 μm wavelength—despite the fact that the metamaterial structure is bianisotropic owing to the lack of inversion symmetry along its surface normal.