Abstract

There exists considerable interest in the development of erasable optical data storage devices. Potential candidates include dye/polymer and phase-change, as well as magnetooptic, media. Direct overwrite schemes are crucial to the attainment of high data rates. This paper compares the physios of several direct overwrite schemes in magnetooptic (MO) media. We have developed a numerical model that evaluates the time dependence of the temperature profile in a moving MO subjected to heating by a laser diode. This profile indicates the net pressure acting on a domain wall attributable to the wall energy and the demagnetizing field in a way similar to magnetic bubble modeling. Noncylindrical symmetry of the domains as well as multiple MO layers can be considered. Our model is sufficiently general to investigate different overwrite proposals, such as the bilayer scheme,¹ domain nucleation and annihilation,² domain destabilization,³ magnetic-field modulation,⁴ and resonant bias coil.⁵

© 1988 Optical Society of America