Photonics: The Vs and Qs of optical microcavities

In certain types of periodic structure, light can be trapped. Such structures are called photonic bandgap materials or photonic crystals, and promise to be as important to the progress of optical devices as semiconductors were to the development of electronic devices. Now the smallest photon trap ever, with a volume of 0.055 μ;m3, has been built in a silicon waveguide. Such devices can accelerate the emission from atoms inside them, promising brighter lasers and faster optical communication.