Bias magnet array for magnetometer

A device comprising:

• a plurality of magnets configured to provide a bias magnetic field to a magneto-optical defect center material;
• a ring magnet holder comprising:
• an outer ring with an outside surface, and
• a plurality of holders extending from the ring, wherein the plurality of holders are configured to hold a plurality of magnets in a same orientation with respect to one another;
• and
• a mount comprising an inside surface, wherein the outside surface of the outer ring slides along the inside surface of the mount.

A device for generating substantially uniform magnetic flux across a magneto-optical material, the device comprising:

• a magneto-optical material that is capable of fluorescing upon the application of certain light and that provides different fluorescence depending upon applied magnetic fields;
• a biasing magnet assembly comprising:
• an outer ring with an outside surface, and
• a plurality of holders extending from the ring, wherein the plurality of holders are configured to hold a plurality of magnets in a same orientation with respect to one another;
• and
• a mount comprising an inside surface, wherein the outside surface of the outer ring slides along the inside surface of the mount,
• wherein the biasing magnet assembly is adjustable to provide a uniform magnetic field to the magneto-optical material.