  The past decade has seen great advances in developing color centers in
diamond for sensing, quantum information processing, and tests of quantum
foundations. Increasingly, the success of these applications as well as
fundamental investigations of light-matter interaction depend on improved
control of optical interactions with color centers -- from better fluorescence
collection to efficient and precise coupling with confined single optical
modes. Wide ranging research efforts have been undertaken to address these
demands through advanced nanofabrication of diamond. This review will cover
recent advances in diamond nano- and microphotonic structures for efficient
light collection, color center to nanocavity coupling, hybrid integration of
diamond devices with other material systems, and the wide range of fabrication
methods that have enabled these complex photonic diamond systems.
