Abstract：An atomic magnetometer based on optically detected magnetic resonance is investigated and demonstrated experimentally. We build an 894 nm external cavity diode laser which is frequency locked to the F=4→F'=3 transition of Cs D1 line with DAVLL spectroscopy. With the phase-locked loop, the frequency of the rf coils is actively locked to the Larmor frequency and the magnetometer tracks the magnetic field variations in a phase coherent manner. An ultimate sensitivity of 19 fT/Hz1/2 and an intrinsic sensitivity of 8.6 pT/Hz1/2 in the magnetic environment which is close to geomagnetic field have been achieved with the spatial resolution smaller than 2 cm.
2012, Vol. 29 
