Corkscrew Polarizer: Strong optical activity, measured in terms of a material's ability to polarize light, usually requires a material several hundred wavelengths thick. Gansel et al. (p. 1513 , published online 20 August; see the cover) show that the tunable electromagnetic response of metamaterials may offer a route to reduce the amount of material required for strongly optically active materials. Based on the standard metamaterials design of the splitring resonator, photolithography was used to define an array of three-dimensional gold nanocorkscrews. Just a single wavelength thickness of the corkscrew design was required for a circular polarizer operating over an octave of bandwidth.

In this tutorial review we highlight fundamental aspects of the physics underpinning the science of photonic crystals, provide insight into building-block assembly routes to the fabrication of different photonic crystal structures and compositions, discuss their properties and describe how these relate to function, and finally take a glimpse into future applications.