An object of the present invention is to provide a thin volume hologram sheet to be embedded sufficiently resistant to a mechanical stress such as a stress including a tensile stress, a shear stress and a compression stress at the time of processing even under a heating condition, a forgery prevention paper and a card using the same. The object is achieved by providing a volume hologram sheet to be embedded comprising a volume hologram layer, and a substrate disposed only on one side surface of the volume hologram layer using an adhesion means, wherein a peeling strength of the volume hologram layer and the substrate is 25 gf/25 mm or more.

In a first aspect, a multilayer film includes a holographic image layer, a first heat-shrinkable layer and a first adhesive layer between the holographic image layer and the first heat-shrinkable layer. In a second aspect, an authentication label includes a holographic image layer, a first heat-shrinkable layer, a first adhesive layer between the holographic image layer and the first heat-shrinkable layer, and a back adhesive layer.

The present invention relates to a layered structure containing at least one layer (i) comprising a thermoplastic material and at least one further layer (ii) comprising a thermoplastic material bearing at least one embossed hologram, to a process for producing such layer composites and to security documents, in particular identification documents, having the layered structure according to the invention.

An object of the present invention is to provide a thin volume hologram sheet to be embedded sufficiently resistant to a mechanical stress such as a stress including a tensile stress, a shear stress and a compression stress at the time of processing even under a heating condition, a forgery prevention paper and a card using the same. The object is achieved by providing a volume hologram sheet to be embedded comprising a volume hologram layer, and a substrate disposed only on one side surface of the volume hologram layer using an adhesion means, wherein a peeling strength of the volume hologram layer and the substrate is 25 gf/25 mm or more.

A dark field digital holographic microscope and associated metrology method is disclosed which is configured to determine a characteristic of interest of a structure. The dark field digital holographic microscope includes an illumination branch for providing illumination radiation to illuminate the structure; a detection arrangement for capturing object radiation resulting from diffraction of the illumination radiation by the structure; and a reference branch for providing reference radiation for interfering with the object radiation to obtain an image of an interference pattern formed by the illumination radiation and reference radiation. The reference branch has an optical element operable to vary a characteristic of the reference radiation so as to reduce and/or minimize variation in a contrast metric of the image within a field of view of the dark field digital holographic microscope at a detector plane.

An object of the present invention is to provide a thin volume hologram sheet to be embedded sufficiently resistant to a mechanical stress such as a stress including a tensile stress, a shear stress and a compression stress at the time of processing even under a heating condition, a forgery prevention paper and a card using the same. The object is achieved by providing a volume hologram sheet to be embedded comprising a volume hologram layer, and a substrate disposed only on one side surface of the volume hologram layer using an adhesion means, wherein a peeling strength of the volume hologram layer and the substrate is 25 gf/25 mm or more.

A visualization system includes an optical recording unit configured to capture optical signals characterizing at least one partial region of an object, a 3D reconstruction unit configured to ascertain spatial data sets, which describe the partial region of the object, based on the captured optical signals, a hologram computational unit configured to ascertain control data for producing a holographic presentation based on the spatial data sets of the partial region of the object, and a visualization unit configured to visualize a holographic presentation of the at least one partial region of the object for a user of the visualization system based on the control data. In addition, a suitable method for producing holographic presentations from optical signals is provided.

The present invention relates to a layered structure containing at least one layer (i) comprising a thermoplastic material and at least one further layer (ii) comprising a thermoplastic material bearing at least one embossed hologram, to a process for producing such layer composites and to security documents, in particular identification documents, having the layered structure according to the invention.

A visualization system includes an optical recording unit configured to capture optical signals characterizing at least one partial region of an object, a 3D reconstruction unit configured to ascertain spatial data sets, which describe the partial region of the object, based on the captured optical signals, a hologram computational unit configured to ascertain control data for producing a holographic presentation based on the spatial data sets of the partial region of the object, and a visualization unit configured to visualize a holographic presentation of the at least one partial region of the object for a user of the visualization system based on the control data. In addition, a suitable method for producing holographic presentations from optical signals is provided.

An object of the present invention is to provide a thin volume hologram sheet to be embedded sufficiently resistant to a mechanical stress such as a stress including a tensile stress, a shear stress and a compression stress at the time of processing even under a heating condition, a forgery prevention paper and a card using the same. The object is achieved by providing a volume hologram sheet to be embedded comprising a volume hologram layer, and a substrate disposed only on one side surface of the volume hologram layer using an adhesion means, wherein a peeling strength of the volume hologram layer and the substrate is 25 gf/25 mm or more.