Quantum diamond microscopy with optimized magnetic field sensitivity and sub-ms temporal resolution

Quantum diamond magnetometers using lock-in detection have successfully detected weak bio-magnetic fields from neurons, a live mammalian muscle, and mouse heart. This opens up the possibility of quantum visualizing microscopic distributions fields. Here, we demonstrate lock-in-based widefield microscopy, achieving mean volume-normalized per-pixel sensitivity 43.9 nTμm1.5/Hz0.5. We optimize by implementing double resonance with hyperfine driving magnetic field alignment along ⟨001⟩ orientation diamond. Additionally, show that sub-ms temporal resolution (∼0.4 ms) can be achieved while keeping at few tens nanotesla per second microscopy. microscopy could step forward in mapping functional activity neuronal networks micrometer spatial resolution.