In a process of manufacturing the volume holographic element, a holographic material layer is irradiated with reference light from the side of a second substrate in the oblique direction, and the holographic material layer is vertically irradiated with object light from the side of a first substrate in an interference exposure process. Since a first translucent anti-reflective layer is formed on the first surface of the first substrate, it is difficult that situation in which the reference light is reflected in the first surface in the oblique direction occurs. In addition, since a second translucent anti-reflective layer is formed on the second surface of the second substrate, it is difficult that a situation in which the object light is reflected in the second surface occurs.

A laser beam (L50) is reflected by a light beam scanning device (60) and irradiated onto a hologram recording medium (45). On the hologram recording medium (45), an image (35) of a linear scatter body is recorded as a hologram by using reference light that converges on a scanning origin (B). The light beam scanning device (60) bends the laser beam (L50) at the scanning origin (B) and irradiates the laser beam onto the hologram recording medium (45). At this time, by changing a bending mode of the laser beam with time, an irradiation position of the bent laser beam (L60) on the hologram recording medium (45) is changed with time. Diffracted light (L45) from the hologram recording medium (45) produces a reproduction image (35) of the linear scatter body on a light receiving surface (R) of the stage 210. When an object is placed on the light receiving surface (R), a line pattern is projected by hologram reproduction light, so that the projected image is captured and a three-dimensional shape of the object is measured.

A first layer of anisotropic material extends along a first plane and includes anisotropic components being parallel to a second plane non-parallel and non-perpendicular to the first plane. The anisotropic components are arranged in cycloidal or helical patterns. The cycloidal or helical patterns define one or more Bragg planes that are non-parallel and non-perpendicular to the first plane and either substantially parallel or substantially perpendicular to the second plane.

Processes and systems are described that can produce images including both three dimensional holographic images and two dimensional variable data, which can provide personalized security features in a document. A photosensitive film can be pressed against a first reflective optical device. A laser beam can be directed through a selected first area of the photosensitive film onto the first reflective optical device to produce a three dimensional holographic image in the photosensitive film. A previously masked second area of the photosensitive film can be pressed against a second reflective optical device. The laser beam can project an image constructed by a spatial light modulator and can be directed through the second area of the photosensitive film onto the second reflective optical device to produce a two dimensional image in the second area. During the process, the web tension of the photosensitive film is controlled.

We describe methods of mass-producing full color, 3D holograms, potentially incorporating a personalized image, which are particularly suitable for security purposes. Broadly speaking in embodiments a method generates, electronically, an interlaced image comprising a set of different views of a 3D object from different angles. This is projected onto a diffusing screen using coherent light and mapped from the screen into an angularly encoded object beam using a lenticular array. The different views in the angularly encoded object beam are then recorded simultaneously into holographic film using a reference beam.

In a process of manufacturing the volume holographic element, a holographic material layer is irradiated with reference light from the side of a second substrate in the oblique direction, and the holographic material layer is vertically irradiated with object light from the side of a first substrate in an interference exposure process. Since a first translucent anti-reflective layer is formed on the first surface of the first substrate, it is difficult that a situation in which the reference light is reflected in the first surface in the oblique direction occurs. In addition, since a second translucent anti-reflective layer is formed on the second surface of the second substrate, it is difficult that a situation in which the object light is reflected in the second surface occurs.

A main object of the present disclosure is to provide a hologram structure having excellent forgery preventability and designability. The present disclosure achieves the object by providing a hologram structure comprising: a hologram layer including a reflection type hologram forming region carrying a recorded phase type Fourier transform hologram that transforms an incident light from a point light source into a desired optical image; and a vapor deposition layer formed so as to come into contact with a concavo-convex surface of the reflection type hologram forming region of the hologram layer, and a size of the reflection type hologram forming region in plan view is in a range of 5 mm square or more and 50 mm square or less.

A laser beam (L50) is reflected by a light beam scanning device (60) and irradiated onto a hologram recording medium (45). On the hologram recording medium (45), an image (35) of a linear scatter body is recorded as a hologram by using reference light that converges on a scanning origin (B). The light beam scanning device (60) bends the laser beam (L50) at the scanning origin (B) and irradiates the laser beam onto the hologram recording medium (45). At this time, by changing a bending mode of the laser beam with time, an irradiation position of the bent laser beam (L60) on the hologram recording medium (45) is changed with time. Diffracted light (L45) from the hologram recording medium (45) produces a reproduction image (35) of the linear scatter body on a light receiving surface (R) of the stage 210. When an object is placed on the light receiving surface (R), a line pattern is projected by hologram reproduction light, so that the projected image is captured and a three-dimensional shape of the object is measured.

The present invention relates to a photopolymer composition comprising a photopolymerizable component and a photoinitiator system comprising a chain-substituted cyanine dye. The invention further provides a photopolymer comprising a photopolymer composition according to the invention, a holographic medium comprising a photopolymer according to the invention, the use of a holographic medium according to the invention, and a process for producing a holographic medium by using the photopolymer according to the invention and the exposure of the corresponding holographic medium with the aid of pulsed laser radiation.

Holograms are generated using a rotatable transparent cylinder and a coherent light source placed inside or outside of such cylinder to record a hologram in a photosensitive film having a reflective film on one side. Recording is done in continuous mode while cylinder is rotating and photosensitive film is translating underneath in contact with cylinder due to friction forces provided by a layer of sticky polymer.