  Nitrogen-vacancy (NV) centers in diamond are versatile candidates for many
quantum information processing tasks, ranging from quantum imaging and sensing
through to quantum communication and fault-tolerant quantum computers. Critical
to almost every potential application is an efficient mechanism for the high
fidelity readout of the state of the electronic and nuclear spins. Typically
such readout has been achieved through an optically resonant fluorescence
measurement, but the presence of decay through a meta-stable state will limit
its efficiency to the order of 99%. While this is good enough for many
applications, it is insufficient for large scale quantum networks and
fault-tolerant computational tasks. Here we explore an alternative approach
based on dipole induced transparency (state-dependent reflection) in an NV
center cavity QED system, using the most recent knowledge of the NV center's
parameters to determine its feasibility, including the decay channels through
the meta-stable subspace and photon ionization. We find that single-shot
measurements above fault-tolerant thresholds should be available in the strong
coupling regime for a wide range of cavity-center cooperativities, using a
majority voting approach utilizing single photon detection. Furthermore,
extremely high fidelity measurements are possible using weak optical pulses.
