Abstract: A reversible recording medium based on optical storage of at least one item of information within a support material, includes at least one layer of support material having: base molecules able to take, in a local zone, a first collective state of molecules able to generate a first signal of second harmonic characteristic of this first collective state of molecules when excited by electromagnetic reading radiation; the base molecules having the first collective state of molecules able to transform, at least in part, into transformed molecules so as to pass to a second collective state of molecules when excited by electromagnetic writing radiation, the molecules having the second collective state of molecules able to generate a second signal of second harmonic characteristic of this second collective state of molecules when excited by the electromagnetic reading radiation. The molecules exhibit a molecular structure based on a coumarin skeleton of Formula (I).

Abstract: A thermally-assisted magnetic recording (TAMR) medium of the present invention includes: a magnetization direction arrangement layer on a substrate; and a magnetic recording layer on the magnetization direction arrangement layer, wherein the magnetization direction arrangement layer is made of at least one selected from a group consisting of Co, Zr, CoZr, CoTaZr, CoFeTaZrCr, CoNbZr, CoNiZr, FeCoZrBCu, NiFe, FeCo, FeAlN, (FeCo)N, FeAlSi, and FeTaC so that a spreading of the heating spot applied from the magnetic head for thermally-assisted recording to the film surface of the magnetic recording medium is suppressed, and that an SN is improved by arranging the magnetization direction of the perpendicularly written recording magnetization to become identical to a perpendicular direction, and realizing the higher recording density.

Abstract: In an optical disk including at least a rewritable phase change material and comprising a recording layer having a reflectivity of more than 15%, an address output value as an address pit signal component occupying in a reproduced signal in a non recording state is prescribed to be 0.18 though 0.27 or a numerical aperture of an address pit signal occupying in a reproduced signal in a non recording state is prescribed to be more than 0.3.

Abstract: An optical recording medium includes a recording layer in which recording of a mark is selectively performed in a depth direction by irradiation of first light, and the mark is formed in multilayer form; and a reflection film reflecting second light of a wavelength different from a wavelength of the first light, and provided on a lower layer side of the recording layer.

Abstract: A near-field optical disk having surface plasmon amplification by stimulated emission of radiation (SPASER) is provided. The near-field optical disk having SPASER includes a transparent substrate, a first transparent dielectric thin film layer formed on the transparent substrate, a SPASER thin film layer formed on the first transparent dielectric thin film layer, a second transparent dielectric thin film layer formed on the SPASER thin film layer, a recording thin film layer formed on the second transparent dielectric thin film layer, and a third transparent dielectric thin film layer formed on the recording thin film layer.