ABSTRACT This work demonstrates efficient Förster resonance energy transfer (FRET) between ensembles of shallow nitrogen‐vacancy (NV) centers located and below a single‐crystal diamond surface and a naturally occurring fluorophore, here a mixture of chlorophyll a and b molecules extracted from Arabidopsis thaliana . The broad fluorescence band of NV centers spectrally overlaps with the chlorophyll molecule's absorption, enabling FRET. Consequently, depositing a chlorophyll layer on the diamond surface reduces the NV fluorescence lifetime from approximately to below , indicating efficient FRET. Laser‐induced photobleaching of chlorophyll restores the unquenched NV lifetime. NV centers located deeper within the diamond ( and ) remain unaffected, confirming that the observed quenching originates from a short range FRET mechanism. The NV ensembles retain their optically detected magnetic resonance (ODMR) contrast while observing FRET, demonstrating preservation of their spin properties. Consequently, these proof‐of‐principle experiments demonstrate the feasibility of combining FRET‐based distance measurements with magnetic sensing using optically readable spins.
Westrich et al. (Thu,) studied this question.