We present a method to determine the direction of a magnetic field in an experimental volume by analyzing the polarization of resonant optical radiation and data that demonstrate this method with a single trapped 40Ca+ ion. With a single trapped 40Ca+ ion, the results are insensitive to the magnitude of the magnetic field, the laser intensity, the detuning, and the bandwidth, provided the fluorescence signal is detectable. This method is applicable to many atomic systems in which optical pumping is possible.
© 2005 Optical Society of America
(120.5410) Instrumentation, measurement, and metrology : Polarimetry
(230.3810) Optical devices : Magneto-optic systems
(260.7490) Physical optics : Zeeman effect
(300.6520) Spectroscopy : Spectroscopy, trapped ion
Justin R. Torgerson, Martin M. Schauer, Steve K. Lamoreaux, and Sebastien Gleyzes, "Single-ion magnetic compass," J. Opt. Soc. Am. B 22, 72-76 (2005)