Direct Overwrite by Light Power Modulation on Magneto-Optical Multi-Layered Media

The present authors have developed a new direct overwrite method on multi-layered Magneto-optical(MO) memory media by light power modulation [1]. (In this experiment double-layered MO memory media are used.) The key points were the media constituing of a memory layer and a reference layer, and an auxiliary magnet which initializes the reference layer. The materials of the two thin film layers we have tested were TbFe/TbFeCo and TbFe/GdTbFe. The both combinations worked well. The former conbination gave us the following result; media velocity = 13.4m/sec, readoput C/N (RBW = 30kHz) = 54dB, 47dB, 44dB for 1MHz, 6MHz, 8MHz respectively.