15-Gbit/in~2 recording on a DWDD disc using a land/groove substrate with a red laser enabled by a side-wall annealing process

摘要

We developed a side-wall-annealing technique for land/groove substrates. By applying this technique to our Domain Wall Displacement Detection (DWDD) Magneto-Optical (MO) recording stack formed on a land/groove substrate, even with an NA of 0.6 and a wavelength of 660 nm, we realized a density of 15 Gbit/in~2 with a sufficiently wide recording tolerance. This density corresponds to a capacity of 4.7 GB mm disc like MiniDisc.