Photonic metamaterials: Recent progress

Complete control of an electromagnetic light wave inside a material requires control of both, its electric and its magnetic component. Metamaterials are man-made effective materials composed of metallic sub-wavelength building blocks ("photonic atoms") that are densely packed into an effective material. Split-ring resonators (SRR) are particularly important "photonic atoms". They can be viewed as tiny LC circuits that can be excited by the incident light field. The incorporation of gain materials appears to be promising and also contains interesting physics. The other major challenge lies in fabricating 3D metal-based metamaterial nanostructures via 3D direct laser writing.