Manipulation of photons at the surface of three-dimensional photonic crystals

Photon manipulation In photonic crystals, suitable variations of the refractive index with a periodicity comparable to the wavelength of the light passing through gives rise to so-called photonic bandgaps, energy (frequency) ranges where the photons cannot propagate. Photonic bandgap materials are candidates to provide the necessary tools for guiding and manipulating photons in optical circuits. So far, the basic approaches for photonic control have been based on embedding artificial defects and light emitters inside these three-dimensional materials. Kenji Ishizaki and Susumu Noda now demonstrate experimentally that, in fact, the surface of such photonic materials support two-dimensional (photonic) surface states that can be easily manipulated to control photons (by guiding and trapping, for instance), thus providing a new and versatile approach for the manipulation of photons in these materials.