  Nitrogen-Vacancy (NV) color centers in diamond have emerged as promising
quantum solid-state systems, with applications ranging from quantum information
processing to magnetic sensing. One of the most useful properties of NVs is the
ability to read their ground-state spin projection optically at room
temperature. This work provides a theoretical analysis of Purcell enhanced NV
optical coupling, through which we find optimal parameters for maximal Signal
to Noise Ratio (SNR) of the optical spin-state readout. We conclude that a
combined increase in spontaneous emission (through Purcell enhancement) and in
optical excitation could significantly increase the readout SNR.
