Realization of a high-density magneto-optical disk through the use of domain wall displacement detection

摘要

The domain wall displacement detection (DWDD)method is a new magneto-optical readout method that utilizes thedomain wall displacement caused by the temperature gradient. Itallows high-density signal patterns to be read out irrespective ofthe resolution limit of the readout optical system.This paper reviews the basic mechanism and the dynamicproperties of this method. A clear readout waveform wasobtained that a flat signal amplitude dependence on the marklength was maintained even for a domain length of 0.1#mu#m.The ghost signal, which was the main problem within thismethod, was suppressed by modifying the recording medium. Asa result, a wide jitter margin could be obtained for a randomsignal with a linear density of 0.1#mu#m/bit.An approach to reducing the track pitch in this method is also described.