A microfabricated photonic magnetometer

An integrated optically-controlled sensor, suitable for remote, high-sensitivity detection of magnetic fields, is presented. The sensor head is free of electrical currents or metal parts, which largely eliminates any spurious fields created by the sensor itself. We demonstrate the operation of the sensor by employing a scheme first published by Bell and Bloom and reach a sensitivity of 2.6 pT/Hz^1/2 at 30 Hz, limited primarily by the photon shot noise of the detector.