High-speed magnetic imaging

Summary form only given. The dynamics of the magnetization in small ferromagnetic structures is a topic of considerable current interest. The timing of this interest is largely attributable to rapid advances in magnetic recording technology, for which such dynamics will dictate the ultimate limits in speed and storage density. High-speed magneto-optic imaging is now being used in an effort to gain new insight into micromagnetic dynamics. The technique is directly analogous to electro-optic sampling of electronic systems. In magneto-optic sampling, magnetic transients are measured via small changes in the plane of polarization of linearly polarized light upon reflection from, or transmission through a sample, the Kerr and Faraday effects, respectively.) Ultrafast measurements with good signal-to-noise are obtained in pump-probe experiments in which the magnetic dynamics are driven using photoconductively switched electromagnetic circuits.