Abstract: A phase-change optical information recording medium in which information can be recorded, reproduced and rewritten and which includes a first transparent substrate having a wobbling guide groove which is spirally formed thereon at a pitch; a first dielectric layer located overlying the first transparent substrate and having an optical thickness of from 80 nm to 200 nm; a phase-change recording layer located overlying the first dielectric layer and having an optical thickness of from 20 to 50 nm when the recording layer is in an erased state; a second dielectric layer located overlying the recording layer and having an optical thickness of from 10 nm to 70 nm; a reflection layer located overlying the second dielectric layer; optionally a third dielectric layer located between the second dielectric layer and the reflection layer; and a second transparent substrate located overlying the reflection layer.

Abstract: A film constitution in an optical recording medium including a light incident side substrate and a light reflecting side substrate cooperatively acting as a base of the medium, and includes, between these substrates, those layers formed by sputtering so as to constitute a laminated structure, which layers include: a phase-change recording layer to be phase-changed between an amorphous phase and a crystal phase by laser light irradiation; a first dielectric layer and a second dielectric layer, each having a protective function and an optical adjusting function for the phase-change recording layer; a reflecting film layer for reflecting the laser light transmitted through the phase-change recording layer; a hardness enhancing layer for enhancing the mechanical strength of the medium; and a protecting layer having a function for reducing thermal damages to the light incident side substrate and an optical adjusting function.

Abstract: The invention relates to materials and devices including these materials having non-erasable optical data capability, as well as to methods of storing optical data and to apparatus for carrying out these functions. In particular there is provided a method of storage of non-erasable optical data comprising exposing data storage material of a three-dimensional optical data storage device to focussed electromagnetic radiation wherein the radiation is of a wavelength and power appropriate to generate micro-cavity formation within the data storage material and wherein the location of micro-cavities encodes for stored data; the data storage material comprising a polymer matrix and a photosensitive agent dispersed through the polymer matrix.

Abstract: The information recording medium accosting to the preferred embodiment of the present invention achieves high-speed, high-density recording. The layer, in which ultra-particles made from an optical absorption metal, dielectric, or recording material are formed into regular arrays, is deposited. Resonant Plasmon excitation and resonance absorption of ultra-particles enable the edges of the recorded marks to be identified clearly and intense absorption to occur only in the given layer depending on the wavelength in the case of the multi-layer medium achieving high-density, large-capacity recording.

Abstract: The present invention provides an optical information medium having excellent weather resistance and repeating characteristics. The optical information medium has a barrier layer between a protective layer and a recording layer. The barrier layer includes GeN or GeON, and at least one element selected from the group consisting of Al, B, Ba, Bi, C, Ca, Ce, Cr, Dy, Eu, Ga, H, In, K, La, Mn, N, Nb, Ni, Pb, Pd, S, Si, Sb, Sn, Ta, Te, Ti, V, W, Yb, Zn and Zr.

Abstract: An optical disc has a support base and at least one information-retrieval layer formed over the support base. The information-retrieval layer is transparent and thinner than the support base. The information-retrieval layer exhibits variation in birefringence within ±20 nmpp (nano meter peak to peak) under double-pass measurements during one rotation of the optical disc.

Abstract: An optical information recording medium having a multilayer structure comprising at least a lower protective layer, a phase-change type optical recording layer, an upper protective layer and a reflective layer, on a substrate, wherein the phase-change type optical recording layer has a composition of Zn&ggr;1In&dgr;1Sb&zgr;1Te&ohgr;1, where 0.01≦&ggr;1≦0.1, 0.03≦&dgr;1≦0.08, 0.5≦&zgr;1≦0.7, 0.25≦&ohgr;1≦0.4, and &ggr;1+&dgr;1+&zgr;1+&ohgr;1=1, whereby overwrite recording is carried out by modulation of light intensity of at least strong and weak two levels, so that a crystalline state is an unrecorded state, and an amorphous state is a recorded state.

Abstract: In an optical disk for high density recording, for preventing the deformation of recording tracks caused by stress which may develop between the substrate and the recording stacked film formed thereon, a stress-compensation layer having a metal element such as Ti or Cr as a main component is provided. The stress-compensation layer undergoes contraction (tensile stress) to compensate for compression stress which develops in the stacked film during cooling after the thermal expansion of the substrate surface that occurs at the end of film formation. The stress-compensation layer has a pillar-like structure which, starting from the lower face, reaches the upper face of the film.

Abstract: There is provided an optical recording medium capable of preventing cross erase and increasing its recording density. The optical recording medium includes: a reflecting film; a first transparent film provided on the reflecting film; a first semitransparent film provided on the first transparent film; a second transparent film provided on the first semitransparent film; a recording film provided on the second transparent film, the recording film being capable of reversibly changing an atomic arrangement; and a third transparent film provided on the recording film. The first semitransparent film has a complex refractive index of n−k satisfying relationships of 0<n<1 and 1<k, and a product of a thickness d (nm) of the first semitransparent film and an extinction coefficient k of the complex refractive index is d×k≦44.

Abstract: An optical disk includes a land and a groove. On this optical disk, data is recorded on both the land and the groove. A distance between the center of the land and the center of the groove adjacent to the land is 0.28 &mgr;m or more. The optical disk has a data efficiency of 80% or more. Thus, an optical disk having a storage capacity of 25 GB or more can be provided.

Abstract: An optical recording medium includes a recording layer, a first dielectric layer disposed on the side of a light incidence plane through which the laser beam enters with respect to the recording layer, a second dielectric layer disposed on the side opposite to the light incidence plane with respect to the recording layer, a heat radiation layer disposed on the side of the light incidence plane with respect to the first dielectric layer and a reflective layer disposed on the side opposite to the light incidence plane with respect to the second dielectric layer, the recording layer containing a phase change material represented by an atomic composition formula: SbaTebGecMnd, where a is equal to or larger than 57 and equal to or smaller than 74, c is equal to or larger than 2 and equal to or smaller than 10, d is equal to or larger than 5 and equal to or smaller than 20, (a+d) is equal to or larger than 74 and equal to or smaller than 81 and a/b is equal to or larger than 2.9 and equal to or smaller than 4.

Abstract: An information recording medium includes a first information layer and a second information layer. The first information layer includes a first recording layer in which a reversible phase change is caused between a crystalline phase and an amorphous phase by irradiation of a laser beam or application of current. The second information layer includes a second recording layer in which a reversible phase change is caused between a crystalline phase and an amorphous phase by the irradiation of the laser beam or the application of the current. The first recording layer is made of a first material, the second recording layer is made of a second material, and the first material is different from the second material.

Abstract: A phase-change optical information recording medium in which information can be recorded, erased, and read includes a substrate and a recording layer overlying the substrate. The recording layer achieves a crystal phase and an amorphous phase. The absorptance Ac of the recording layer in the crystal phase against light having a wavelength of from 370 nm to 450 nm is lower than the absorptance Aa of the recording layer in the amorphous phase against the light. Information is recorded on the recording medium with a recording wavelength of from 370 nm to 450 nm at a recording pitch of 0.3 &mgr;m to 0.52 &mgr;m.

Abstract: A phase-change optical information recording medium capable of recording information therein, reproducing recorded information therefrom, rewriting recorded information, and erasing recorded information therefrom, which phase-change optical information recording medium is provided with a recording layer containing therein a phase-change recording material including Ge, Ga, Sb, Te, and one element selected from the group consisting of Mg and Ca, which recording material is capable of performing a reversible phase transition from a noncrystalline phase to a crystalline phase and vice verse with the application of an electromagnetic wave thereto.

Abstract: An optical recording medium includes a support substrate and two information recording layers, an information recording layer close to a light incidence plane through which a laser beam is projected including a first dielectric film, a second dielectric film and a recording layer disposed between the first dielectric film and the second dielectric film and a thickness of each of the first dielectric film and the second dielectric film being determined so as to be equal to or larger than D21 and equal to or smaller than D22, where D21 is smaller than D2, D22 is larger than D2, and D21 and D22 are determined in such a manner that the dependency X of light transmittance of the information recording layer close to the light incidence plane on the wavelength of a laser beam is smaller than 1.

Abstract: An optical disk has a substrate, a first protective layer formed on the substrate, a recording layer formed on the first protective layer, a second protective layer formed on the recording layer, and a reflective layer formed on the second protective layer. The recording layer includes a composition expressed as (SbxTe1-x)aGebInc in which atomic ratios are 0.77≦x≦0.84, 0.85≦a≦0.95, 0.01≦b≦0.10 and 0.01≦c≦0.10 where a+b+c=1.

Abstract: Optical information-recording media comprise a first transparent substrate through which a laser beam enters, a first information-recording layer deposited on the first transparent substrate, a first reflection film formed on the first information-recording layer, an intermediate layer deposited on the first reflection film, a second information-recording layer formed on the intermediate layer, a second reflection film deposited on the second information-recording layer, and a second substrate provided on the second reflection film. The recording film of each of the first and second information-recording layers has a main composition represented by (GeTe)xSb2−yInyTe3, and its composition ratio is within ranges of 0.04≦y<2 and 4≦x≦8.

Abstract: An initialization method in which a phase change optical recording medium is initialized with a laser beam having a power density of from 15 to 22 mW/&mgr;M2 at a linear velocity of from 8 to 12 m/s. The phase change optical recording medium is formed of a transparent substrate having a guide groove on the surface thereof, a first protective layer, a recording layer, a second protective layer and a reflective layer. The recording layer material may be represented by the following composition formula: Ag&agr;X&bgr;Sb&dgr;Te&egr;Ge&ggr;, wherein X is at least one of Ga, In, Tl, Pb, Sn, Bi, Cd, Hg, Mn, Dy, Cu and Au, and &agr;, &bgr;, &dgr;, &egr;, and &ggr; have units of atomic % and satisfy particular relationships.

Abstract: A description is given of a phase-change optical data storage medium (20 having a recording stack (2) with a recording layer (6) and a metal reflective layer (3) comprising at least one transparent layer (4, 8) of the material indium tin oxide (ITO). Use of an ITO layer (4, 8) in the recording stack (2) improves the cooling behavior of the recording layer (6) combined with good optical contrast. Thus, higher possible data rates are achieved.

Abstract: An optical recording medium comprising a recording layer which comprises a phase-change recording material causing a reversible phase change between a crystalline phase and an amorphous phase by irradiation with an electromagnetic wave, wherein the phase-change recording material mainly comprises materials expressed by the composition formula X&agr;Ge&bgr;Mn&ggr;Sb&dgr;Te&egr; with each of the components respectively fulfills 0≦&agr;≦5, 1≦&bgr;≦5, 1≦&ggr;≦10, 65 ≦&dgr;<80, 15≦&egr;≦25, and &agr;≦&ggr; (where X expresses at least one of Ga and Sn, &agr;, &bgr;, &ggr;, &dgr;, and &egr; expresses atomic percentage, and fulfills &agr;+&bgr;+&ggr;+&dgr;+&egr;=100).

Abstract: An optical recording medium includes a recording layer in which a record mark can be formed by projecting a laser beam thereonto, a first dielectric layer disposed on the side of a light incidence plane with respect to the recording layer, a second dielectric layer disposed on the opposite side to the light incidence plane with respect to the recording layer, a heat radiation layer disposed on the side of the light incidence plane with respect to the first dielectric layer and a reflective layer disposed on the opposite side to the light incidence plane with respect to the second dielectric layer, the recording layer containing a phase change material represented by a general formula: (SbxTe+x)+y My wherein M is an element other than Sb and Te, the first dielectric layer containing a mixture of ZnS and SiO2, the reflective layer containing Ag or alloy containing 90 atomic % or more of Ag, and the heat radiation layer containing 90 atomic % or more of aluminum nitride.

Abstract: The present invention provides a write-once optical information recording medium that can achieve a high reflectance and favorable recording and reproducing characteristics such that a high C/N ratio and high sensitivity even when information is recorded/reproduced with high density. This medium includes a transparent substrate and at least one information layer formed on the substrate. The information layer includes a recording layer made of a material including Te, O and M, where M is at least one element selected from the group consisting of Al, Si, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Hf, Ta, W, Re, Os, Ir, Pt, Au and Bi. A reflectance with respect to a light beam incident from the side of the transparent substrate after recording information on the recording layer is lower than a reflectance before recording.

Abstract: An optical information recording medium is composed of at least a phase-change type recording layer 4 provided on a substrate 1. The optical information recording medium is conducted to record and erase information by changing a phase of the phase-change type recording layer by irradiating light. The phase-change type recording layer is further composed of TiwGexSbyTez, wherein each of w, x, y and z is in atomic percent and satisfies following relations: 0.5≦w≦4.0, 3.4≦x≦14.5, 2.1≦y/z≦4.0 and w+x+y+z=100.

Abstract: An optical information recording medium of the present invention includes a first substrate, a second substrate placed in parallel with the first substrate, and an information layer placed between the first substrate and the second substrate, wherein the information layer includes a recording layer and a dielectric layer (lower dielectric layer/upper dielectric layer) placed so that a distance from the dielectric layer to the recording layer is 20 nm or less. The recording layer is changed between at least two different states that can be identified optically by irradiation of a laser beam incident from the first substrate side, and the dielectric layer contains ZnS and Si as main components.

Abstract: An information recording medium which ensures high reliability and favorable overwrite cyclability is provided, even when an interface layer is not provided between a recording layer and a dielectric layer. The recording layer 4 and the dielectric layers 2 and 6 are formed on the surface of the substrate 1. In the recording layer 4, a phase change is generated between a crystal phase and an amorphous phase by irradiation of light or application of an electric energy. The dielectric layers 2 and 6 are Zr—Zn—S—O-based material layers comprising Zr, Zn, S and O, preferably consisting essentially of a material expressed, for example, with the formula (ZrO2)X(Zn—S)100−X (mol %) wherein X is in the range of 50≦X≦80.

Abstract: A multilayer phase change information recording medium including plural information layers containing at least a first information layer and a last information layer, each of which includes a recording layer in which information is recorded utilizing a phase change between a crystalline phase and an amorphous phase. At least one of the plural information layers other than the last information layer includes a first lower protective layer, a first recording layer located overlying the lower protective layer, a first upper protective layer located overlying the first recording layer, a first reflective layer located overlying the first upper protective layer, and a heat diffusion layer located overlying the first reflective layer and which mainly contains In, Zn and O.

Abstract: A phase-change optical recording medium includes a phase-change optical recording film that permits reversible phase change between a crystalline phase and an amorphous phase upon irradiation with light, and an interface film formed of hafnium oxide, or a mixture of hafnium oxide and at least one oxide selected from the group consisting of cerium oxide, titanium oxide and zirconium oxide, and formed in contact with at least one surface of the phase-change optical recording film.

Abstract: Disclosed in this invention is a phase change optical recording material for a rewritable recording medium with a high speed crystallization and excellent erasibility, which comprises a composition having the formula of: (AaBbCc)x(GeaSbbTec)1−x wherein, A is an element selected from the elements belonging to the IVB group in the periodic table; B is an element selected from the elements belonging to the VB group in the periodic table; C is an element selected from the elements belonging to the VIB group in the periodic table; a, b and c are atomic ratios; x is a mole fraction in the range of 0 to 1; and at least one of A, B and C has a higher atomic number and thus a smaller diatomic bond strength than that of the corresponding element in the GeSbTe part.

Abstract: An optical information recording medium, especially a CD-RW medium, that can undergo direct overwriting at high speed is disclosed. The optical information recording medium includes a transparent substrate, at least a recording layer and a reflective layer on or above the substrate and is capable of performing at least one of recording, erasing and rewriting information by irradiating and scanning with focused light to thereby form and/or erase recording marks on the recording layer.

Abstract: An information recording medium of the present invention includes a first substrate, a second substrate disposed so as to be opposed to the first substrate, a first information layer disposed between the first substrate and the second substrate, a second information layer disposed between the first information layer and the second substrate, and an intermediate layer disposed between the first information layer and the second information layer. The first information layer includes a first recording layer that is transformed in phase reversibly between a crystal phase and an amorphous phase with a laser beam, and the second information layer includes a second recording layer that is transformed in phase reversibly between a crystal phase and an amorphous phase. The first recording layer contains, Ge, Sn, Sb, and Te, and has a thickness of 9 nm or less.

Abstract: The present invention provides an optical information recording medium including a substrate having successively disposed thereon a light-reflective layer, a recording layer and a cover layer, wherein information can be recorded on and reproduced from the recording layer by irradiating a laser beam from a side at which the cover layer is disposed, and a surface of the light-reflective layer at a side at which the recording layer is disposed has a central surface average roughness SRa of 30 nm or smaller and a number of projections having a height from a reference plane of 50 nm or greater, as determined with an atomic force microscope (AFM), of 30 (number/90 &mgr;m angle) or less.

Abstract: The inventions relates to a laser beam optical recording medium which features several read/write levels, comprising a first half-transparent level and at least a second level, the first one being close to the laser transmitting source, each level comprising a phase changing material layer with two stable states controlled by a laser beam, where the phase changing material is a metallic alloy whose chemical formula writes as: [(GeyTe1-y)a(SbzTe1-z)1-a]1-b(In1-xTex)b with: 0.4≦y≦0.6 0.3≦z≦0.5 0.4≦x≦0.6 0.3≦a≦0.5 0.01≦b≦0.3 the reflection coefficient of the first level being in the range from 10% to 30%, the transmission coefficient being at least 45%, the writing power being lower than 23 mW and the erasing power being lower than 10 mW.

Abstract: An phase-change optical disk comprises a substrate, a first protective layer, a first thermostable layer, a recording layer, a second thermostable layer, a second protective layer, an absorptance control layer, and a heat-diffusing layer which are provided in this order from a side on which a laser beam comes thereinto, wherein a recording layer material has composition ratios which are within a range surrounded by composition points of B3 (Bi3, Ge46, Te51), C3 (Bi4, Ge46, Te50), D3 (Bi5, Ge46, Te49), D5 (Bi10, Ge42, Te48), C5 (Bi10, Ge41, Te49), and B5 (Bi7, Ge41, Te52) on a triangular composition diagram. Recrystallization is not caused even when information is recorded on an inner circumferential portion, a reproduced signal is scarcely deteriorated even when rewriting is performed multiple times, and any erasing residue of amorphous matters scarcely appears at an outer circumferential portion.

Abstract: An information recording medium includes a first information layer and a second information layer. The first information layer includes a first recording layer in which a reversible phase change is caused between a crystalline phase and an amorphous phase by irradiation of a laser beam or application of current. The second information layer includes a second recording layer in which a reversible phase change is caused between a crystalline phase and an amorphous phase by the irradiation of the laser beam or the application of the current. The first recording layer is made of a first material, the second recording layer is made of a second material, and the first material is different from the second material.

Abstract: A product for recording information by use of laser light includes a recording layer being able to change between an amorphous state and a crystalline state so as to record information, the recording layer having a thickness falling within a first range defined relative to a wavelength of the laser light, a protection layer having a thickness falling within a second range defined relative to the wavelength of the laser light, a heat releasing layer having a thickness falling within a third range defined relative to the wavelength of the laser light, and a transparent substrate supporting the layers. The first, second, and third ranges are selected such that a phase of the laser light reflected by the amorphous state and a phase of the laser light reflected by the crystalline state have a phase difference larger than a predetermined phase amount.

Abstract: An optical information recording medium of the present invention includes: a substrate with at least one selected from the group consisting of a groove and a pit formed on one surface thereof; at least one information layer provided on the surfaces of the substrate, the information layer including at least one selected from the group consisting of a recording film and a reflective film; a resin layer provided on the information layer; and a light transmission layer provided on the resin layer. The resin layer includes a first resin film and a second resin film disposed in this order from the side of the light transmission layer, and when a water absorption rate of the first resin film is represented by A1 and a water absorption rate of the second resin film is represented by A2, A1 and A2 satisfy: A1>A2. The first resin film and the second resin film may have a different flexural modulus of elasticity.

Abstract: An information recording medium capable of high-density recording and accurate reproduction and also capable of repeated recording and reproduction, an information recording device that employs the information recording medium has a Co—Si oxide thin film 1 constructed such that columnar crystals 2 are separated by an intergranular phase 3 which contains SiO2 having a lower coefficient of thermal conductivity than the columnar crystals 2. Therefore, the intergranular phase 3 prevents heat transfer from one columnar crystal 2 to another. In addition, the intergranular phase 3 separates columnar crystals 2 from each other, so that the crystalline structure of each columnar crystal 2 is not affected by its adjacent columnar crystal 2.

Abstract: Provided is a medium having a phase change recording layer wherein crystallization of the recording layer is facilitated, and at the same time, wherein the region to be crystallized is crystallized at an accurate dimension. The optical recording medium has a recording layer 4 comprising at least one phase change layer 41 and at least one functional layer 42 in contact with said phase change layer. The phase change layer 41 in its as-deposited state is amorphous, and crystals having Fm3m structure or R3m structure are produced upon crystallization of this layer. The functional layer 42 in its as-deposited state is crystalline, and contains crystals having Fm3m structure. The material used for the functional layer 42 is the one which exhibits a thermal conductivity of 0.03 to 5 W/cmK as measured in thin film form of 100 nm thick.

Abstract: An ultra-high density data storage and retrieval unit has a phase-change layer for storing and retrieving data and at least one other layer. The phase-change layer and/or the other layer comprises a two-dimensional material, primarily one of the chalcogen-based materials.

Abstract: A phase change optical recording medium according to an embodiment of this invention includes a substrate, a reflecting layer which reflects a light beam, a phase change recording layer which is arranged between the substrate and the reflecting layer and changes between a crystalline state and an amorphous state when irradiated with the light beam, a first dielectric layer which is arranged between the substrate and the reflecting layer, and a second dielectric layer which is arranged between the substrate and the first dielectric layer and has a thermal conductivity lower than that of the first dielectric layer.

Abstract: The subject matter of the invention is to provide an optical recording medium with improvements in repeated overwrite characteristics, write power margin, archival stability and the like. The invention provides an optical recording medium having a semi-transparent layer mainly comprising Ag, a first protective layer comprising a dielectric, a phase-change recording layer comprising an alloy mainly comprising SbxTe1−x (0.7<x≦0.9), a second protective layer comprising a dielectric, and a metallic reflective layer in this order, wherein the medium further has an interdiffusion-protection layer between the semi-transparent layer and the first protective layer where the first protective layer comprises a sulfur-containing dielectric, and the medium has a higher reflectance to light incident on the semi-transparent layer side with the recording layer being in an amorphous state than in a crystalline state.

Abstract: To provide an information recording medium which permits high density recording/reproduction, which has good thermal stability, and which, due to the use of an interface layer with a high sputter rate, has good recording/reproduction characteristics and is excellent for mass production. An information recording medium wherein the thickness of an interface layer 3 is 0.25 or more but 0.67 or less of the total thickness of a first protective layer 2 and the interface layer 3, and the interface layer 3 contains at least tantalum (Ta) and oxygen (O). The medium is excellent for mass production and has good recording/reproduction characteristics for high density recording/reproduction.

Abstract: An information recording medium has a light transmissive layer, a first information recording layer, a transparent layer, and a second information recording layer sequentially stacked to reproduce information signals upon exposure of the light transmissive layer to laser light, wherein the first information recording layer comprises a first protective layer, a phase change recording film, and a second protective layer sequentially from the light transmissive layer, and the rate of power fluctuation between a reproducing light passing through a recorded region of the first information recording layer and that passing through an unrecorded region of the first information recording layer during reproduction of the information signals from the second information recording layer, are within 10%, whereby the information signals can be recorded/reproduced on/from the second information recording layer through the first information recording layer satisfactorily.

Abstract: The present invention relates to a rewritable multi-layer recording medium that ensure appropriate data reading from and writing in an arbitrary recording layer of a plurality of recording layers. The recording layers are stacked via spacer layers. Each recording layer is made from a material of which reflectance changes upon radiation of a light beam. Information or data is written in the recording layer as a result of reflectance change. Each recording layer has at least one groove and/or at least one pit. A certain layer in which the information is to be written (recorded) has a rewritable region. An adjacent layer has a window region through which the light beam passes and reaches the rewritable region. The window region imparts a diffraction effect, which is different from a diffraction effect impartable from a region surrounding the window region, to the passing light beam.

Abstract: An optical recording medium 10 comprises a substrate 1, first protective layer 2, interfacial layer 3, recording layer 4, second protective layer 5, light absorbing and heat generating layer 6, third protective layer 7, reflection layer 8 and a protective film 9 laminated in order. The light absorbing and heat generating layer 6 is a metal layer or an alloy layer containing more than one element out of Ge, Sn, Pb, Cr, Ti, In, Si, Cd, Se, W, Mo, Zr, Nb, Zn and Hf, so that a reflectivity of the optical recording medium 10 and an optical modulation factor, which is an optical modulation factor in a phase changing state of crystalline or amorphous, in the recording layer 4 can be always maintained in high. Accordingly, a recording sensitivity of the recording layer 4 in the optical recording medium 10 can be increased without deteriorating a characteristic such as reflectivity and jitter.

Abstract: A phase change type information storage medium is provided, which achieves high-speed recording/reproduction. A DVD-RW disc having a substrate formed with grooves, lands, and land pre-pits, on which are laminated a first dielectric layer, a phase-change recording layer, a second dielectric layer, a reflective layer, and an overcoat layer. The disc is rotated at a 3.49-7.0 m/sec linear speed while being irradiated with a laser beam of 600-700 nm wavelength focused by an objective lens of 0.55-0.7 numerical aperture to the phase-change recording layer from the substrate side. The phase-change recording layer is made of a Ge-In-Sb-Te material, and the reflective layer is made of an Ag-Nd-Cu material. The first dielectric layer has a 65-85 nm thickness, the phase-change recording layer has a 10-20 nm thickness, the second dielectric layer has a 13-23 nm thickness, and the reflective layer has a 100-225 nm thickness.

Abstract: A compound constructed by N (N is an integer of 2 or more) kinds of phases containing at least one kind of elements selected from a group consisting of Co, Ti, V, Cr, Mn, Fe, Ni, Si, Pb, Bi and Al. At least one kind to (N−1) kinds among the N kinds of phases are continuous phases, and the other phases are discontinuous phases.

Abstract: An optical information recording composition suitable for use as a recording layer of an optical information recording medium. The optical information recording composition contains Sb, and one or two elements selected from N and O, and optionally one or more elements M selected from Ge, Te, Bi, Sn, Ag, Au, In, Pb, Pd, Pt, Al, Si, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ta, Ga, Zr, Nb, Mo, Ru, Rh, Hf, W, Re, Os, Ir, Dy and Th. A light beam having a wavelength of 200-800 nm can be used to record information on the optical information recording medium and retrieve information therefrom.

Abstract: A re-recordable data storage medium is disclosed. One embodiment of the medium includes a dielectric material and a filler material. The dielectric material is organized in columnar channels over which memory cells are logically distributed. The filler material is within the columnar channels to realize the memory cells. The filler material of each memory cell has at least a first configuration and a second configuration. The first configuration corresponds to a first storable logical value, and the second configuration corresponds to a second storable logical value.

Abstract: A high-density information recording medium free from lowering the reflectance by over-write of a large number of times and exfoliation defect in a structure for suppressing cross-erase. This medium includes, over a substrate having a groove shape, a recording layer, and three-layered thin films of a first interference layer, a second interference layer and an interface layer having mutually different compositions and disposed on a laser beam incidence side of the recording layer in order named from the laser beam incidence side. The first interference layer has a smaller refractive index and a larger thermal conductivity than the second interference layer, the interface layer is interposed between the second interference layer and the recording layer, and a distance between the first interference layer and the recording layer is greater than at least a groove depth.