The present volume on optical data storage technology discusses high-speed/high-density magneto-optic recording; a compact optical head integrated with chip elements for CD-ROM drives; disk memory systems using 1D hologram technology; transfer function characteristics of superresolving systems; servo technology for a three-beam overwritable magnetooptical disk drive; signal and noise characteristics in magnetooptical signal detection with elliptically polarized light; and simplified analysis of the readout waveform for an elliptical mark. Also discussed are magnetically induced superresolution for high-density optical disk systems, magnetic properties and microstructure in (Fe,Co)/Pt multilayer films, high-density overwrite recording for a phase-change medium using a visible-light laser diode, continuous manufacturing of thin cover sheet optical media, magnetooptic multilayers, and a three-beam magnetooptical disk drive with overwrite function.