Abstract: A multilayer optical memory of WORM (write-once-read-many) type has photosensitive layers with fluorescent reading. The disc contains a transparent substrate and multiple information layers spatially divided from one another by polymer layers and assembled using adhesive layers. Information is stored in a photosensitive substance within spiral grooves. The photosensitive substance can be formed as a continuous layer or as discrete grooves on a non-photosensitive background. Various compositions for the photosensitive substance allow recording in by changing fluorescence bleaching or emitting, with threshold-type recording.

Abstract: A fluorescent composition for use with single-layer and multilayer optical discs for CD ROM, DVD and WORM type devices with fluorescent reading is disclosed. The composition comprises a fluorescent dye, film-forming polymer, plasticizer, surfactant and light stabilizer. A method of increasing fluorescent signal level from the optical discs both for single-layer and multilayer optical memory materials is also disclosed along with the resulting optical discs.

Abstract: High sensitive organic dye-in-polymer (DIP) medium for write-once-read-many (WORM) optical discs with fluorescent reading. The medium consists of a fluorescent color means, capable of absorbing writing radiation produced by a laser, a compound capable of generating free radicals upon influence of heat produced by the writing radiation and a polymer capable of producing a translucent film enabling high quantum yield of the fluorescence induced in the color means. The color means can be selected from xanthene dyes of the eosine and rhodamine groups, acridine, oxazine, azine, peylene, violanthrone, cyanine, phtalocyanine, indigoide colors and porphyries. The free radicals generating compound can be chosen from the group of compounds comprising azo and diazoi compounds or peroxyde compounds. The film producing polymer can be selected from the group of compounds comprising cellulose ethers, vinyl resins or acrylic resins.

Abstract: This invention concerns a luminescent optical memory material and method of forming this material, including the encoding of information by a photographic process. The method involves the use of silver halide crystals of a defined size range, with the optional use of sensitizers, emulsion stabilizers, and other agents followed by the absorption of luminescent dyes on the developed silver particle to form a luminescent optical memory system. The method involves synthesis of a photographic emulsion with silver halide crystals of a defined size range, applying photographic emulsion to a substrate, exposing to light photochemical treatment and a process of transformation of the silver particles formed in the places exposed by light into luminescent particles. The method involves obtaining a multi-layer luminescent material for a three-dimensional optical memory devices.

Abstract: An optical recording medium for fluorescent WORM discs comprising a fluorescent dye, nitrocellulose and film-forming polymer is disclosed. The medium provides a high capacity optical memory for WORM discs, including 3-dimensional optical memory systems.

Abstract: A CD-ROM type optical disk, whether single-layer or multi-layer, is formed on a substrate having pits in its surface. The pits are filled with a fluorescent composition. Multiple disks such as that one can be glued on top of one another. Suitable fluorescent compositions include xanthene dyes of the eosine group, xanthene dyes of the rhodamine group, acridine dyes, oxazine dyes, azine dyes, indigoide dyes, perylene dyes, violanthrone dyes, cyanine dyes, phthalocynanine dyes, and porphyrins.

Abstract: In a multilayer recordable optical medium, each recording layer includes a luminophore that fluoresces under reading laser light and a quencher capable of quenching the luminophore fluorescence. Initially, the luminophore and the quencher are not intermixed, so that the default state of the luminophore is fluorescent. During writing, focused writing radiation heats a spot in the medium so as to cause the luminophore and the quencher to be intermixed, thereby quenching the fluorescence.

Abstract: A dye-in-polymer composition for in fluorescent WORM discs comprises about 0.1 to 10% by weight of a fluorescent dye capable of absorbing laser radiation and transforming the absorbed light into heat; about 10 to 80% by weight of nitrocellulose and a film forming polymer. The dye containing solution is applied to substrate of an optical reading medium by a spin, roller or dip coating. The method utilizes a focused laser beam for scanning the recording layer.

Abstract: This invention concerns a luminescent optical memory material and method of forming this material, including the encoding of information by a photographic process. The method involves the use of silver halide crystals of a defined size range, with the optional use of sensitizers, emulsion stabilizers, and other agents followed by the absorption of luminescent dyes on the developed silver particle to form a luminescent optical memory system. The method involves synthesis of a photographic emulsion with silver halide crystals of a defined size range, applying photographic emulsion to a substrate, exposing to light photochemical treatment and a process of transformation of the silver particles formed in the places exposed by light into luminescent particles. The method involves obtaining a multi-layer luminescent material for a three-dimensional optical memory devices.

Abstract: In a multilayer recordable optical medium, each recording layer includes a luminophore that fluoresces under reading laser light and a quencher capable of quenching the luminophore fluorescence. Initially, the luminophore and the quencher are not intermixed, so that the default state of the luminophore is fluorescent. During writing, focused writing radiation heats a spot in the medium so as to cause the luminophore and the quencher to be intermixed, thereby quenching the fluorescence.

Abstract: A method of manufacturing a multi-layer optical information carrier with fluorescence reading/recording is presented. A structure is fabricated, being formed of a substrate carrying a fluorescent film on one or both surfaces thereof, wherein the substrate is transparent with respect to incident radiation used for the fluorescence reading/recording. A patterned structure is applied to the fluorescent film under predetermined process conditions, such as to produce a fluorescent patterned structure with a surface relief in the form of an array of discrete fluorescent regions. The same procedure is repeated a required number of times, so as to obtain at the end of the process a multi-layer optical information carrier.

Abstract: This invention concerns a luminescent optical memory material and method of forming this material, including the encoding of information by a photographic process. The method involves the use of silver halide crystals of a defined size range, with the optional use of sensitizers, emulsion stabilizers, and other agents followed by the absorption of luminescent dyes on the developed silver particle to form a luminescent optical memory system. The method involves synthesis of a photographic emulsion with silver halide crystals of a defined size range, applying photographic emulsion to a substrate, exposing to light photochemical treatment and a process of transformation of the silver particles formed in the places exposed by light into luminescent particles. The method involves obtaining a multi-layer luminescent material for a three-dimensional optical memory devices.