Photonic band gap materials are solids that strongly diffract light, ideally at visible and near-infrared wavelengths. They are ordered dielectric structures, such as silica-air or titania-polymer, with sub-micron periodic length scales. Many exciting applications have been proposed for these materials, including cavities for thresholdless lasing, planar waveguiding, and photon localization. Our group's efforts in this area began only in 1998, when graduate student Peng Jiang began to explore better ways to form silica colloidal films. …
