A surface relief structure includes a recording medium configured to be structurally modified when exposed to interfering and non-interfering portions of radiation beams, the structurally modified recording medium including, when viewed in a two-dimensional cross-section along one of the axes of the recording medium a plurality of equally spaced steps of fine-sized periodicity superimposed upon a plurality of deep depressions of substantially coarse-sized periodicity. The structurally modified recording medium is configured to produce in reflection single and multiple colors in a broad spectral range when illuminated by a source of light.

The invention improves holographic imaging systems by being modular with deployment in a lens-less configuration or with a microscope objective, leading to a resolution range of 5.5 and to 0.5 m/pixel, respectively, and resulting in a resolvable particle size range of several microns to a few cm between two setups. The invention includes variable sampling length between two windows (e.g., a sampling volume of 71.4 mL per hologram at 12 cm). Holograms are recorded with a 49203280 pixels digital camera. i.e., 15.3 MB per image, at a maximum rate of 3.2 Hz, such that free stream water sampling a 14 L/minute occurs. This is orders of magnitude higher than sampling of other imaging systems while including larger/variable sample volume, inclusion of copper shutters to prevent biofouling during long-term deployments, including deployment in different operation modes. No single previous system achieves all these things at the same time.

The present invention relates to a security document and/or document of value with a hologram in a visually changeable window as a novel security element, and also to a method for producing the same.

Examples include imaging one or more objects contained inside a droplet. A method includes generating at least one hologram of the one or more objects contained in the droplet by using in-line lens-free imaging. The at least one hologram includes at least one artifact that is caused by the droplet and that affects the at least one characteristic of the one or more objects contained in the droplet. The method includes at least partially removing the at least one artifact or the cause of the at least one artifact. The method further includes generating an image, after or during removing the at least one artifact or the cause of the at least one artifact. The image includes the one or more objects. The method also comprises recognizing the at least one characteristic of the one or more objects based on the image.

A method for reconstructing optical properties of a diffracting object immersed in a liquid medium using a reconstruction system that comprises a spatially coherent light source and a matrix photodetector, wherein the liquid medium and the matrix photodetector are separated by a distance along a vertical direction. The method comprises illuminating the liquid medium, measuring (with the matrix photodetector) an intensity of a diffraction pattern transmitted by the illuminated medium along a vertical direction, and reconstructing the optical properties of the diffracting object at a reconstruction height according to a reconstruction algorithm from the measured intensity, wherein the reconstruction height has a value less than that of the distance between the medium and the matrix photodetector along the vertical direction.

Method for computing the code for the reconstruction of three-dimensional scenes which include objects which partly absorb light or sound. The method can be implemented in a computing unit. In order to reconstruct a three-dimensional scene as realistic as possible, the diffraction patterns are computed separately at their point of origin considering the instances of absorption in the scene. The method can be used for the representation of three-dimensional scenes in a holographic display or volumetric display. Further, it can be carried out to achieve a reconstruction of sound fields in an array of sound sources.

The immersive, interactive system according to the present disclosure employs interconnected hardware, firmware, software, and mixed technology comprising projection systems, smart entertainment technologies, tracking systems, sound, light, visual displays, and other physical and/or special effect displays to create an entertainment experience that brings people together to enjoy a common story, theme, music, or game. In one embodiment, the system takes the form of a magical campfire that interacts with members of the audience to present an interactive and customized visual and audio display and story. The system may connect and interact with other technological platforms and smart devices to supplement the processing and experience, and may be updated to maintain relevant and timely content, and add additional features. The system may exist in a large scale environment, such as a theatre, theme park, or museum, or may be condensed to a smaller-scale version for home use.