US Patent 10274551 Magnetometer sensor with negatively charged nitrogen-vacancy centers in diamond

The disclosure relates to a magnetometer sensor with negatively charged nitrogen-vacancy centers in diamond. One example embodiment is a magnetometer sensor. The magnetometer sensor includes a diamond crystal with one or more negatively charged nitrogen-vacancy centers. The magnetometer sensor also includes one or more light sources. Further, the magnetometer sensor includes an electrode. In addition, the magnetometer sensor includes a read-out module. The read-out module includes a read-out circuit configured to read-out a photocurrent from the electrode and a lock-in amplifier. The lock-in amplifier includes a first input, a second input, and an output. The magnetometer sensor additionally includes a microwave source configured to apply a microwave field to the negatively charged nitrogen-vacancy centers. The microwave source includes a microwave generator for generating continuous wave microwaves and a microwave modulator configured to modulate the continuous wave microwaves. Still further, the magnetometer sensor includes a processor.