  Diamond is a unique material with exceptional physical and chemical
properties that offers potential for the realization of high-performance
devices with novel functionalities. For example diamond's high refractive
index, transparency over wide wavelength range, and large Raman gain are of
interest for the implementation of novel photonic devices. Recently, atom-like
impurities in diamond emerged as an exceptional system for quantum information
processing, quantum sensing and quantum networks. For these and other
applications, it is essential to develop an integrated nanophotonic platform
based on diamond. Here, we report on the realization of such an integrated
diamond photonic platform, diamond on insulator (DOI), consisting of a thin
single crystal diamond film on top of an insulating silicon dioxide/silicon
substrate. Using this approach, we demonstrate diamond ring resonators that
operate in a wide wavelength range, including the visible (630nm) and
near-infrared (1,550nm). Finally, we demonstrate an integrated, on-chip quantum
nanophotonic network, consisting of ring resonators coupled to low loss
waveguides with grating couplers, that enables the generation and efficient
routing of single photons at room temperature.
