Compact magnetooptical disk for coded data storage

A compact magnetooptical disk having 500 times the capacity of a 13.34-cm (5.25-in.) floppy disk has been developed for use in coded data storage applications. Low error rates are attained by the use of advanced highly sensitive polarization detection optics and high-quality recording media. Progress in these fields has been based on noise analysis of readout signals. The disk drive can write and erase data by sectors and can also play current write-once-type optical disks. This disk/disk drive unit promises to lead to enhanced storage capacity and to support the current drive to enhance office automation and other information systems.