The present disclosure relates to apparatuses and methods for performing in-line lens-free digital holography of objects. At least one embodiment relates to an apparatus for performing in-line lens-free digital holography of an object. The apparatus includes a point light source adapted for emitting coherent light. The apparatus also includes an image sensing device adapted and arranged for recording interference patterns resulting from interference from light waves directly originating from the point light source and object light waves. The object light waves originate from light waves from the point light source that are scattered or reflected by the object. The image sensing device comprises a plurality of pixels. The point light source comprises a broad wavelength spectrum light source and a pinhole structure. The image sensing device comprises a respective narrow band wavelength filter positioned above each pixel that filters within a broad wavelength spectrum of the point light source.

According to an embodiment, a holographic image sensor comprises a lens focusing object light incident from outside of the holographic image sensor to the holographic image sensor, a filter transmitting a predetermined wavelength band of light of the focused object light, a light receiving unit receiving interference light to sense a holographic image, and a reference light source directly emitting reference light having the predetermined wavelength band to the light receiving unit.

The present disclosure discloses a hologram recording device and a hologram recording method. The hologram recording device comprises an object imaging unit comprising a cavity for accommodating an object whose interior wall is a reflective surface, and a light modulating unit configured to produce incident light and reference light interfering with the incident light and to direct the incident light to the object imaging unit. The cavity is provided with an imaging aperture for imaging of the object and at least one light incidence aperture for allowing the incident light to enter the cavity and irradiate on the object, such that an image of the object is formed at a location corresponding to the imaging aperture outside the cavity, and image light produced upon the imaging of the object interferes with the reference light at the location for recording of an image surface hologram.

A holographic image recording method is disclosed, that is realized through utilizing a holographic image fetching and recording device, including the following steps: using an image fetching device to fetch an image of a target object placed on a rotation table rotating at a fixed speed, the image thus obtained is transmitted to a display panel through a connection line; using a light emitting unit to emit coherent light to a first reflector; that reflects the coherent light to light splitter; and the light splitter splits the coherent light along a first light path and a second light path into an object light and a reference light, and transmits them onto a holographic film to interfere with each other, to form a holographic image. A holographic image reconstructing method is also disclosed, to reconstruct and form a 3D holographic image floating above the holographic film.

A system and method of providing internet-based teaching utilizing a holographic projection is disclosed. The system receives a query from a user via a user device. The system parses the query and generates a response to the query. The system generates a holographic image emulating a real-life educator. Further, the system generates a voice response corresponding to the response. The system integrates the holographic image and the voice response and presents it at the user device in order to create an impression that a real-life professor responded to the query. The system captures the essence of in-person instruction, offering students a uniquely engaging and adaptive educational journey in the digital realm.

A display panel (1) comprising a body of optical material, the body having at least one optical image recorded therein in an encoded manner, wherein the image is selectively reconstructable and viewable (5, 6, 7) by illuminating the panel (1) using at least one light source (3a, 3b, 3c) under selected illumination conditions, wherein the image is reconstructable and viewable (5, 6, 7) such that at least one first optical property or parameter of the reconstructed image (e.g. its geometry, position in space, colour, its dynamic appearance) is selectable in value from amongst variable values of the at least one first optical property or parameter, or whose value is actively modifiable over time, as a function of or in dependence on the value of at least one second optical property or parameter of the illumination conditions of the at least one light source (e.g. its/their position(s) or spacing(s) relative to the panel (1), its/their colour, brightness/optical intensity, polarisation, direction of light ray propagation, application of a scanning technique to illuminate the panel (1)) which is selectable from amongst variable values thereof or which is actively modifiable in value over time.