Abstract
Two laser beams are focused onto a thin permalloy film. By changing the direction of the magnetization of the permalloy film the magneto-optic Kerr-effect is exploited either to rotate the plane of polarisation or to modulate the amplitude of the reflected light. As a modulating aperture, the displacements can be controlled accurately by the amplitude or the frequency of the applied field. The film is characterized for our application by measuring the velocity of the domain wall displacements using two focused light beams at known separations. By measuring the delay between the modulation of the reflected beams it is possible to accurately determine the beam separation under the condition of reproducible wall movements. Therefore, a moving domain wall acts like a high-speed modulator.
Get full access to this article
View all access options for this article.