Diamond-optic enhanced photon collection efficiency for sensing with nitrogen-vacancy centers.

We present a design to increase the amount of collected fluorescence emitted by nitrogen-vacancy color centers in diamond used for quantum-sensing. An improvement was measured in collected fluorescence when comparing oppositely faced emitting surfaces by a factor of 3.8(1). This matches ray-tracing simulation results. This design therefore improves on the shot noise limited sensitivity in optical readout-based measurements of, for instance, magnetic and electric fields, pressure, temperature, and rotations.