  We demonstrate minimization of ion micromotion in a linear Paul trap with the
use of a high finesse cavity. The excess ion micromotion projected along the
optical cavity axis or along the laser propagation direction manifests itself
as sideband peaks around the carrier in the ion-cavity emission spectrum. By
minimizing the sideband height in the emission spectrum, we are able to reduce
the micromotion amplitude to approximately the spread of the ground state wave
function. This method is useful for cavity QED experiments as it allows for
efficient 3-D micromotion compensation despite optical access limitations
imposed by the cavity mirrors. We also show that sub-nanometer micromotion
compensation is possible with our current system.
