Sensing magnetic fields with diamonds and green laser light

Nitrogen-Vacancy (NV) centres in diamonds have quantum properties that allow them to sense weak magnetic fields. This is relevant both for research and health care as diamond magnetometers have the potential of being both cheaper and less inva- sive than current methods. The measurements are usually done by giving the NV centres energy from green laser light and detecting red light that they then emit. In this paper, we give an introduction to that technique before explaining a new measurement method where we do not need to measure any red light but can just look at how much of the green laser light that the diamond absorbs