Optical Properties of Metacrystals Based on Protein Nanocages

The optical properties of 3D metacrystals made gold nanoparticles in protein nanocages are studied. These have sizes tens micrometers and high structural quality. Through microspectroscopy measurements model calculations it is demonstrated that the show plasmonic absorption green wavelength range largely transparent red infrared ranges. By using empty as placeholders metacrystal lattice, possible to control how strongly metamaterial absorbs. Measurements on a pyramidal deflects visible light. deflection shows evidence for anomalous refraction at short wavelengths normal long wavelengths. refractive dispersion ascribed relation metamaterial.