Design of diamond microcavities for single photon frequency down-conversion

We propose monolithic diamond cavities that can be used to convert color-center Fock-state single photons from emission wavelengths to telecommunication bands. We present a detailed theoretical description of the conversion process, analyzing important practical concerns such as nonlinear phase shifts and frequency mismatch. Our analysis predicts sustainable power requirements (≲ 1 W) for a chipscale nonlinear device with high conversion efficiencies.