Woodpiles for Photons

Abstract

With the right design and size, a periodic structure can exhibit unusual and useful optical properties. In particular, photonic crystals can be fabricated in which photons experience a band gap analogous to the band gap for electrons in a solid crystal. In their Perspective, Hillebrand and Gösele discuss results reported in the same issue by Ogawa et al. in which a structure known as a three-dimensional photonic crystal of woodpile geometry has been fabricated from gallium arsenide. The structures contain a light-emitting layer whose wavelengths correspond to the band gap of the photonic crystal. The output of light is suppressed, but it can take place, and even be controlled via the local point defect modes. The ability to fabricate such integrated devices represents a major step forward in creating complex photonic circuits for optical communications.