Magnetooptical recording technology toward 100 Gb/in2

摘要

Concerning areal recording density, magnetooptical (MO) disknpossesses an advantage compared to another optical disks and alsonmagnetic hard disk (HDD), since the linear density of MO disk can benincreased by using a perpendicular magnetic recording, and the trackndensity also can be increased by using an optical tracking method. Onnthe other hand, in the region of high density HDD, demagnetizationnproblem is discussed for archival data storage. However, since thencoercive force of MO recording material is over five times larger thannthat of HDD, it does not become such a severe problem for MO recording.nIn case of very-high-density recording, the readout signal isndrastically reduced due to decreasing both the recorded domain size andnthe optical resolution. However, in the case of MO, the small readoutnsignal can be enhanced by using a novel readout technique named asnmagnetic amplifying MO system and the extremely small signal also can bendetected. Thus, it is found that the MO has probability of achieving annextremely high density storage such as 100 Gb/in2