text: In physics, optically detected magnetic resonance (ODMR) is a double resonance technique by which the electron spin state of a crystal defect may be optically pumped for spin initialisation and readout.
  Like electron paramagnetic resonance (EPR), ODMR makes use of the Zeeman effect in unpaired electrons. The negatively charged nitrogen vacancy centre (NV) has been the target of considerable interest with regards to performing experiments using ODMR.
  ODMR of NVs in diamond has applications in magnetometry and sensing, biomedical imaging, quantum information and the exploration of fundamental physics.