Feasibility Study of Concurrent ROM-RAM Optical Disk

Abstract

In the area of magneto optical disk memory, we have focused our efforts on achieving high density recording, recording readout and high speed access. We have also been looking into the potential benefits of magneto optical disk memory. CONCURRENT ROM-RAM optical disk memory, which comprises phase pit information and magneto optical information, has very good potential because the memory capacity is ideally twice as large as that of conventional memories and both ROM and RAM are reproduced simultaneously by means of laser feedback method and so-called differential detection readout. We have confirmed the feasibility of CONCURRENT ROM-RAM through basic experiments. However, we have also found that the polarization noise generated by the edge of the phase pit is quite dominant.