An array of nanorods can reflect nearly all light over a precise set of wavelengths, making this a promising material for filters and other optics applications.

Stéphane Collin at the Laboratory of Photonics and Nanostructures in Marcoussis, France, and his colleagues built a grid of 500-nanometre-wide silicon-nitride nanorods spaced 3 micrometres apart. The researchers then shone infrared light onto the array. Most of the light passed through, but the rods reflected nearly all of the light within a narrow range of wavelengths. The authors developed a model that suggests that the rods behave much like a crystal, scattering light many times to ultimately reflect it.

Phys. Rev. Lett. 109, 143903 (2012) http://dx.doi.org/10.1103/PhysRevLett.109.143903