OVERWRITE RECORDING AND READING ON QUADRILAYER MO DISKS USING AN OPTICAL HEAD WITH A RED-LIGHT LD

Abstract

  To achieve a higher density recording on the overwritable exchange-coupled quadrilayer MO disk, the overwrite recording characteristics using 680nm laser diode were investigated. High recording sensitivity is obtained on the disk with about 1000Å magnetic film. CNR more than 46dB is obtained at 0.66μm mark length, and 0.5μm/bit recording with bit error rate less than 1×10^-5 succeeds at 1.2μm track pitch zone.