A comparison of nitrogen vacancy centre defect fluorescence characteristics in optically trapped nanodiamonds

Bright fluorescent nanodiamonds (NDs) that are suitable for combined optical trapping and magnetic resonance sensing experiments are typically prepared from high pressure high temperature (HPHT) diamond. The nature of the synthesis method yields a poly-dispersion of sizes and shapes, and with a range of optoelectronic properties that may be more or less suitable for magnetic resonance sensing. In this paper we explore the possibility of using trapping metrics and fluorescence properties as a proxy for identifying NDs with strong optically detected magnetic resonance (ODMR) contrast. Our results suggest that larger NDs, characterized by a strong fluorescence count and high trap stiffness typically yield more favourable ODMR contrast.