Technology is described for methods and systems for a diffractive optic device (525) for holographic projection. The diffractive optic device can include a lens (535) configured to convey a hologram. The lens (535) further comprises a patterned material (510) formed with an array of cells having a non-planar arrangement of cell heights extending from a surface of the patterned material. The lens further optionally comprises a filling material (530) to fill gaps on both surfaces of the patterned material.

A method for integrating a hologram into the body of a security document that has a laminated body. The method includes: providing a holographic film having a backing substrate layer and a photo layer; providing additional substrate layers; carrying out a laminating process in order to form the laminated body, the holographic film together with the additional substrate layers being collated to form a substrate layer stack and being combined, together with the additional substrate layers, in a high-pressure, high-temperature laminating method to form the laminated body. There is also described a corresponding security document body.

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.

Transmission and reflection mode VHOEs are designed and fabricated for use in imaging and other applications. These VHOE provide high diffraction efficiency with minimal chromatic aberrations and astigmatism across the bandwidth. The lens provides optical power within the bandwidth centered relative to several wavelengths to magnify (focus or collimate) input light and is transparent for the rest of the image spectrum. In transmission mode, two VHOE are fabricated in such a way as to introduce compensating adjustments that minimize the astigmatism and chromatic aberrations introduced by the bandwidth of the input light. Two VHOEs are required to provide an on-axis imaging system to magnify light to form an image and reduce the chromatic aberrations across the bandwidth and reduce the astigmatism while maintaining high diffraction efficiency (DE). In reflection mode, a single VHOE is configured to act as a mirror at the specified wavelength and bandwidth and to magnify light to form an image and, consequently, has minimal level of astigmatism and chromatic aberration.

A volume holographic film (such as a photopolymer) that is pre-recorded with patterns subsequently is used to encode LED or low-power laser light reflections from an eye into a binary pattern that can be read at very high speeds by a relatively simple complementary metal-oxide-semiconductor (CMOS) sensor that may be similar to a high framerate, low resolution mouse sensor. The low-resolution mono images from the film are translated into eye poses using, for instance, a look up table that correlates binary patterns to X, Y positions or using a pre-trained convolutional neural network to robustly interpret many variations of the binary patterns for conversion to X, Y positions.

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 hologram that includes a formation layer and a reflection layer that are laminated. The formation layer has an optical phase modulation structure on a first interface in contact with the reflection layer. When reference light emitted from a point light source enters through a second interface different from the first interface of the formation layer, the entirety or part of an image to be reconstructed by the optical phase modulation structure is reconstructed as spatial information on the point light source side relative to the second interface.

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.

There are provided volume holograms and combinations of lenticular lenses and holograms in particular for security applications. In embodiments, a volume hologram comprises a holographic medium (102) including a first optical interference structure which, upon illumination, replays a first image (110); wherein the first image includes a lenticular lens layer (111) including an array of lenticules and a lenticular image layer (113) including first (114) and second (115) interlaced images corresponding with the array of lenticules.

An improved polymeric sheet material for use in making polymeric security documents such as banknotes is provided. The inventive polymeric sheet material has one or more integrated and/or applied optical security devices. Polymeric security documents made using these improved polymeric sheet materials are also provided.