We propose and optimize a vertically-loaded diamond microdisk resonator (VLDMoRt) coupled to a nitrogen-vacancy (NV) center in diamond for efficient collection of zero-phonon-line emission into low numerical aperture (NA) free-space modes. The VLDMoRt achieves a Purcell enhancement of 172 with 39% of the emitted light collected within a NA of 0.6, leading to a total external spin-photon collection efficiency of 0.33. As the design is compatible with established nanofabrication techniques and couples to low-NA modes accessible by cryogenic free-space optical systems, it is a promising platform for efficient spin-photon interfaces based on diamond quantum emitters.
@article{arxiv.2105.05695,
title = {A vertically-loaded diamond microdisk resonator spin-photon interface},
author = {Yuqin Duan and Kevin C. Chen and Dirk R. Englund and Matthew E. Trusheim},
journal= {arXiv preprint arXiv:2105.05695},
year = {2021}
}