  Photonic crystal cavities can localize light into nanoscale volumes with high
quality factors. This permits a strong interaction between light and matter,
which is important for the construction of classical light sources with
improved properties (e.g., low threshold lasers) and of nonclassical light
sources (such as single and entangled photon sources) that are crucial pieces
of hardware of quantum information processing systems. This article will review
some of our recent experimental and theoretical results on the interaction
between single quantum dots and photonic crystal cavity fields, and on the
integration of multiple photonic crystal devices into functional circuits for
quantum information processing.
