Future Generation Magneto-Optical Media from a Manufacturing Point of View

Abstract

Future-generation magneto-optical (MO) media are studied from a manufacturing point of view. The first priority to expand MO media application is to realize low-cost technology. Of course, high capacity and high-speed capability are necessary to compete with other memories. Non-overwriting media provide a major stream for higher capacity disks such as 2× (two times the memory capacity of the first-generation disk) and 3×, because of their cost-effective production line using fine-tuned, already-repaid sputtering machines. Concerning overwriting schemes, field modulation media are very attractive in terms of media cost and high-density recording, but is limited to a single-sided disk. Light intensity modulation has an advantage for high-speed overwriting. In this paper, I propose an attractive scheme for a drastic reduction of cost per MByte. Field modulation writing and magnetic superresolution (MSR) readout are combined to increase memory density. More than 700 MB is possible on a 3.5-inch single-sided disk using a 780 nm current-generation laser.