Performance of magneto-optical recording media with direct overwrite capability

Abstract

The feasibility of directly overwriting certain magneto-optical recording materials without the use of an external magnetic field has recently been demonstrated in our laboratory. In this report experiments to evaluate the beam positioning accuracy necessary for successful direct overwrite, the effects of static bias fields on the direct overwrite process, and the possibility of writing and erasing domains of arbitrary length on direct-overwrite materials are discussed. The data show that an error in beam positioning of at least 75% of the nominal domain diameter is tolerable for complete erasure without an external applied field. Application of particular values of dc bias field is shown to decrease the pulse width required to write while only slightly narrowing the allowed margin of erase pulse width, thus raising the allowed data rate.