Holographic storage medium, article and method
AssigneeGeneral Electric Company
InventorsMichael McLaughlin, Christoph Erben
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Abstract
Disclosed are a holographic storage medium, a method for producing a holographic storage medium, a method for storing data on a holographic storage medium, and an optical reading method. The holographic storage medium comprises an dimensionally stable film that is formed by partially curing a mixture, wherein said mixture comprises (a) a binder material; (b) a curable photoactive material; (c) an optional sensitizer; and (d) a photoinitiator, and wherein at least a portion of the photoactive material remains unreacted after the forming. Articles comprising holographic storage media in various forms are also disclosed.
Claims35
A method of making a holographic storage medium comprising an dimensionally stable film, said method comprising:
- forming said dimensionally stable film by partially curing a mixture,
- wherein said mixture comprises
- a binder material;
- a curable photoactive material;
- an optional sensitizer;
- and
- a photoinitiator,
- and wherein at least a portion of the photoactive material remains unreacted after the forming of the holographic storage medium.
A holographic storage medium comprising:
- a dimensionally stable film, said dimensionally stable film of said holographic storage medium comprising
- a binder material;
- an unreacted curable photoactive material;
- an optional sensitizer;
- and
- a photoinitiator.
A holographic storage medium comprising a dimensionally stable film, wherein (a) the dimensionally stable film is in a sealed transparent mold, or (b) is partially encapsulated by a substrate, wherein said dimensionally stable film and said substrate are optionally joined by an adhesive layer;
- wherein said transparent mold and said substrate are transparent to radiation of wavelength in the range of from about 300 nanometers to about 900 nanometers, and wherein said transparent mold and said substrate are selected from the group consisting of glass, polycarbonates, polyesters, polyamides, polyolefins, and combinations thereof.
A method of storing data on a holographic storage medium comprising the steps of:
- (i) forming the holographic storage medium in the form of an dimensionally stable film, said dimensionally stable film formed by partially curing a mixture, said mixture comprising:
- a binder material;
- a curable photoactive material;
- an optional sensitizer;
- a photoinitiator, and
- an optional thermal curing catalyst;
- wherein at least a portion of the photoactive material remains after the partial cure process;
- wherein the binder material comprises either an inert material;
- a reaction product of a thermally curable mixture comprising at least one curable monomer;
- or combinations thereof;
- wherein the photoactive material comprises one or more epoxide compounds;
- wherein (a) the curing step to form said dimensionally stable film is performed inside a transparent mold, followed by removing the dimensionally stable film from the mold, or wherein (b) the curing step takes place within a sealed transparent mold, or wherein (c) the dimensionally stable film obtained after a separate curing step may be at least partially encapsulated by a substrate;
- wherein said dimensionally stable film and said substrate are optionally joined by an adhesive layer;
- wherein said transparent mold and substrate are transparent to radiation of wavelength in the range of from about 300 nanometers to about 900 nanometers, and wherein said transparent mold and substrate are selected from the group consisting of glass, polycarbonates, polyesters, polyamides, polyolefins, and combinations thereof;
- and
- (ii) illuminating the holographic storage medium with both a signal beam containing data and a reference beam, thereby forming within the holographic storage medium an interference pattern, wherein the photoinitiator initiates polymerization of at least a portion of the photoactive material in response to the signal beam and reference beam, resulting in formation of a hologram in the holographic storage medium.
An optical reading method comprising:
- (i) forming a holographic storage medium comprising an dimensionally stable film, said dimensionally stable film formed by partially curing a mixture, said mixture comprising:
- a binder material;
- a curable photoactive material;
- an optional sensitizer;
- a photoinitiator, and
- an optional thermal curing catalyst;
- wherein at least a portion of the photoactive material remains after the partial cure process;
- wherein the binder material comprises an inert material;
- a reaction product of a thermally curable mixture comprising at least one curable monomer;
- or combinations thereof;
- wherein the photoactive material comprises one or more epoxide compounds;
- wherein (a) the curing step to form said dimensionally stable film is performed inside a transparent mold, followed by removing the dimensionally stable film from the mold, or wherein (b) the curing step takes place within a sealed transparent mold, or wherein (c) the dimensionally stable film obtained after the curing step may be at least partially encapsulated by a substrate, wherein said dimensionally stable film and said substrate are optionally joined by an adhesive layer;
- wherein said transparent mold and substrate are transparent to radiation of wavelength in the range of from about 300 nanometers to about 900 nanometers, and wherein said transparent mold and substrate are selected from the group consisting of glass, polycarbonates, polyesters, polyamides, polyolefins, and combinations thereof;
- (ii) illuminating the holographic storage medium with both a signal beam containing data and a reference beam, thereby forming within the holographic storage medium an interference pattern, wherein the photoinitiator initiates polymerization of at least a portion of the photoactive material, resulting in formation of a hologram in the holographic storage medium;
- and
- (iii) illuminating the holographic storage medium with a read beam effective to read the data contained by diffracted light from the hologram.
An article comprising:
- a prefabricated transparent mold and a holographic storage medium comprising an uncured mixture,
- wherein said holographic storage medium is sealed within said transparent mold, said mixture comprising:
- a binder material;
- a curable photoactive material;
- an optional sensitizer;
- and
- a photoinitiator.
Dependencies are inferred from the claim text.