High-Q optical nanocavities in planar photonic crystals

Planar photonic crystals are constructed by combining two-dimensional periodic structures with high refractive index contrast slabs. By suppressing the loss in these structures due to imperfect confinement in the third dimension, one can fully take advantage of their relatively simple fabrication, and achieve the functionality of three-dimensional photonic crystals. One of the greatest challenges in photonic crystal research is a construction of optical nanocavities with small mode volumes and large quality factors, for efficient localization of light. Beside standard applications of these structures (such as lasers or filters), they can potentially be used for cavity QED experiments, or as building blocks for quantum networks. This paper will address our theoretical and experimental results on optical nanocavities based on planar photonic crystals, with mode volumes as small as one half of cubic wavelength of light in material, and with Q factors even larger than 1 x 10^4