Rotating Fluorescent Nanodiamond Assemblies With Focused Laguerre–Gaussian Beams

ABSTRACT Optical tweezers which utilize structured light fields enable the rotation of trapped nanoparticles through the transfer of orbital angular momentum (OAM) from holographically generated Laguerre–Gaussian (LG) modes. In this research we use OAM transfer to demonstrate controlled rotation of bright fluorescent nanodiamond clusters assembled in a focused higher‐order LG beam. We find that the assemblies can be effectively rotated in a two‐dimensional optical trap with orbital frequencies of up to 5 Hz. We use video tracking to explore the orbital dynamics and angular confinement of the trapped assemblies, and assess how orientation stability affects optically detected magnetic resonance (ODMR) measurements under a weak external magnetic field. By collecting ODMR spectra at multiple points along the orbit, we show that the constrained two‐dimensional motion can provide additional insights for vector magnetic field reconstruction.