All-dielectric photonic metamaterials operating beyond the homogenization regime

Photonic metamaterials made of graded photonic crystals operating near the bandgap frequency region are proposed for field manipulation around l=1.5μm. Proof-of-concept structures have been studied using Hamiltonian optics and FDTD simulation, fabricated, and characterized using farfield optical measurements. Experimental results are in good agreement with predictions, showing the interest of graded photonic crystals as an (ultra-low loss) alternative solution to the use of metamaterials combining dielectric and metallic materials with sub-wavelength unit cells.