The invention relates to a photopolymer formulation comprising a polyol component, a polyisocyanate component, a writing monomer, and a photoinitiator, containing a coinitiator and a dye having the formula F An, where F stands for a cationic dye and An″ stands for an anion, wherein the dye having the formula F An comprises a water absorption of =5%. The invention further relates to a holographic medium, in particular in the form of a film, containing a photopolymer formulation according to the invention, to the use of such a medium for recording holograms, and to a special dye that can be used in the photopolymer formulation according to the invention.

The invention relates to a photopolymer formulation comprising a polyol component, a polyisocyanate component, a writing monomer, and a photoinitiator, containing a coinitiator and a dye having the formula F An, where F stands for a cationic dye and An″ stands for an anion, wherein the dye having the formula F An comprises a water absorption of =5%. The invention further relates to a holographic medium, in particular in the form of a film, containing a photopolymer formulation according to the invention, to the use of such a medium for recording holograms, and to a special dye that can be used in the photopolymer formulation according to the invention.

An optical information storage medium includes a substrate and a multilayer polymeric film. The multilayer polymeric film has a first surface and an opposite second surface that extend the length of the multilayer polymeric film. The second surface is adhered to a surface of the substrate. The multilayer polymeric film includes a plurality of coextruded alternating polymeric active data storage layers and polymeric buffer layers.

An optical information storage medium includes a substrate and a multilayer polymeric film. The multilayer polymeric film has a first surface and an opposite second surface that extend the length of the multilayer polymeric film. The second surface is adhered to a surface of the substrate. The multilayer polymeric film includes a plurality of coextruded alternating polymeric active data storage layers and polymeric buffer layers.

Techniques disclosed herein relate to holographic optical materials and elements. An example of a holographic recording material includes matrix monomers characterized by a first refractive index and configured to polymerize to form a polymer matrix, writing monomers dispersed in the matrix monomers and characterized by a second refractive index different from the first refractive index, and a photocatalyst for controlled radical polymerization of the writing monomers. The writing monomers are configured to polymerize upon exposed to recording light. The photocatalyst is dispersed in the matrix monomers. The photocatalyst includes, for example, a transition metal photocatalyst or a metal-free organic photocatalyst, such as a photocatalyst for atom transfer radical polymerization or a transition metal photocatalyst for addition fragmentation chain transfer polymerization.

The present invention discloses a reflective holographic storage method and device, in which a reflection layer is plated on a back side of a holographic storage medium, and a new reference light is formed by utilizing the reflection layer, so that a phase conjugate reproduction light of a hologram is obtained. According to the invention, a recording device and a reading device can be provided on the same side of a medium, thereby obtaining a more compact system, reducing design difficulty, improving system stability, and improving the SNR (signal-noise ratio) of reproduction light by the interference between reproduction light and a conjugate reproduction light.

A grating coupler may be fabricated by exposing a photopolymer layer to grating forming light for forming periodic refractive index variations in the photopolymer layer. The photopolymer layer may be exposed to apodization light for reducing an amplitude of the periodic refractive index variations in a spatially-selective manner. The apodization may also be achieved or facilitated by subjecting outer surface(s) of the photopolymer layer to a chemically reactive agent that causes the refractive index contrast to be reduced near the surface(s) of application. The apodized refractive index profile of the gratings facilitates the reduction of optical crosstalk between different gratings of the grating coupler.

The present disclosure relates to a hologram recording medium having a main relaxation temperature (Tr) of 0° C. or less, wherein the Tr is a point where a rate of change of phase angle with respect to temperature is the largest in a range of −80° C. to 30° C. in dynamic mechanical analysis. The present disclosure also relates to an optical element including the same and a holographic recording method using the hologram recording medium.

To provide a hologram recording composition that can further improve diffraction characteristics and transparency of a hologram.

The present technology provides a hologram recording composition containing a heteropoly acid, a photopolymerizable monomer, a photopolymerization initiator, and a sensitizing dye having absorption in a visible light region in the presence of an acid. The present technology also provides a hologram recording medium including at least a photocurable resin layer containing a heteropoly acid, a photopolymerizable monomer, a photopolymerization initiator, and a sensitizing dye having absorption in a visible light region in the presence of an acid. Furthermore, the present technology also provides a diffraction optical element using the hologram recording medium. Moreover, the present technology also provides an optical device, an optical component, and an image display device using the diffraction optical element.

To provide a hologram recording composition that can further improve diffraction characteristics and transparency of a hologram.

The present technology provides a hologram recording composition containing a heteropoly acid, a photopolymerizable monomer, a photopolymerization initiator, and a sensitizing dye having absorption in a visible light region in the presence of an acid. The present technology also provides a hologram recording medium including at least a photocurable resin layer containing a heteropoly acid, a photopolymerizable monomer, a photopolymerization initiator, and a sensitizing dye having absorption in a visible light region in the presence of an acid. Furthermore, the present technology also provides a diffraction optical element using the hologram recording medium. Moreover, the present technology also provides an optical device, an optical component, and an image display device using the diffraction optical element.