Magnetic Vortex Dynamics Using the Optical Cotton-Mouton Effect

Abstract

The first use of linear magnetic birefringence (optical Cotton-Mouton effect) to observe a magnetic resonance is reported. This allows us to make the first direct observation of resonant motion of a ferromagnetic vortex. This vortex is present in an easy-plane garnet film at the intersection of two 90\ifmmode^\circ\else\textdegree\fi{} N\'eel walls. Agreement between the resonant frequencies and our theory confirms a previously proposed equation of vortex motion.