青紫色レーザーを用いた相変化光ディスク技術

抄録

The use of blue-violet laser sources such as SHGs devices and GaN laser diodes is one of the most promising strategies for continuing to increase the recording capacity of phase-change optical disks. Shorter wavelength lasers can be combined with other approaches, including the use of an objective lens with large NA of close to or exceeding 1.0 and a dual-layer disk structure. Phase-change materials for use under these conditions are required to show large changes in the optical constants of n or k combined with sufficiently large optical transmittance at the shorter wavelength, as well as a sufficiently high crystallization rate to compensate for the smaller laser spot size. It is thought that Ge-Sb-Te will be applicable to the memory layer ofphase-change optical disks using blue-violet laser light in the same way as red laser light is now used.