Atomic magnetometers utilizing the spin of alkali metal vapor have been proposed. U.S. Pat. No. 7,038,450 proposes a high sensitivity atomic magnetometer having a light source for circularly polarized light and a light source for probe light. Phys. Rev. Lett. 94, 123001 (2005) describes an atomic magnetometer for detecting nuclear magnetic resonance (NMR) signals and RF signals by utilizing a resonance phenomenon. U.S. Pat. No. 7,061,237 proposes a magnetic resonance imaging (MRI) apparatus using a remote detection technique and a single optical path type atomic magnetometer.