A method of forming a security device includes: a holographic image layer, diffusion element, and barrier layer. A region of the barrier layer includes a heat-transformable material. The method further includes selectively applying heat at a plurality of positions within the region of the barrier layer, in accordance with a predetermined pattern, so as to modify the heat-transformable material such that the region of the barrier layer is selectively rendered passable to the diffusible substance at each of the plurality of positions, thereby permitting diffusion of the diffusible substance between the regions of the diffusion element and the holographic image layer such that, at a plurality of positions within the region of the holographic image layer and corresponding to the predetermined pattern, the volume hologram is dimensionally modified so as to become viewable in a second observable colour, different from the first observable colour.

The invention relates to a multilayer body with a volume hologram layer and a partial opaque layer, arranged on a surface of the volume hologram layer, which is present in a first area and is not present in a second area. The invention furthermore relates to a method for the production of such a multilayer body, as well as a security element and security document with such a multilayer body.

A security document having a security element including a multilayer body with a volume hologram layer and a partial opaque layer, arranged on a surface of the volume hologram layer, which is present in a first area and is not present in a second area.

Techniques disclosed herein relate to optical devices. Resins with different optical properties can be deposited in different areas to provide increased optical functionality. It can be difficult to design a single photopolymer material that meets several technical requirements. Different resins can be deposited on the same substrate to make a single film with spatially varying properties. Different resins can also be applied to different substrates in a stack. By using different resins, an optical component can be made that meets several technical requirements.

Techniques disclosed herein relate to optical devices. Resins with different optical properties can be deposited in different areas to provide increased optical functionality. It can be difficult to design a single photopolymer material that meets several technical requirements. Different resins can be deposited on the same substrate to make a single film with spatially varying properties. Different resins can also be applied to different substrates in a stack. By using different resins, an optical component can be made that meets several technical requirements.

A method for forming a volume hologram film having security elements which are formed as a transfer section of the volume hologram film is described, wherein the volume hologram film has n volume hologram layers arranged one over another. The production of the volume hologram film is carried out in a roll-to-roll method with the following method steps: a) providing a carrier film from a supply roll; b) applying an i-th photopolymer layer to the carrier film; c) forming an i-th volume hologram in the photopolymer layer; d) forming an i-th volume hologram layer by curing the i-th photopolymer layer; e) repeating process steps b) to e) n1 times; f) applying an adhesive layer to the background layer; g) winding the volume hologram film onto a take-up roll.

Photosensitive polymers for recording volume holograms, anisotropic volume holograms, and corresponding volume holographic elements are described herein.

A security document having a security element including a multilayer body with a volume hologram layer and a partial opaque layer, arranged on a surface of the volume hologram layer, which is present in a first area and is not present in a second area.

The present invention provides a means for suppressing an occurrence of a ghost by enhancing diffraction efficiency of a holographic optical element having a volume hologram recording layer. The present invention is a holographic optical element including: a volume hologram recording layer containing a photopolymer; and at least one adjacent layer which is in contact with the volume hologram recording layer and contains a resin, wherein a diffraction grating is formed so as to extend from the volume hologram recording layer to the adjacent layer.

The invention relates to a multilayer body with a volume hologram layer and a partial opaque layer, arranged on a surface of the volume hologram layer, which is present in a first area and is not present in a second area. The invention furthermore relates to a method for the production of such a multilayer body, as well as a security element and security document with such a multilayer body.