The inventors have discovered a method to improve image quality in holography and, for the first time, utilize lenses made from birefringent materials to advantageously split an incoming beam of either coherent or incoherent light into two coincident beams with different focal lengths that interfere with one another and thus create holograms free of electro-optical or pixelated devices. This discovery has many advantages over current methods to create holograms in which many components, including multiple lenses, other electro-optical devices, and/or beam paths are necessary to create holograms. The current invention provides a purely optical holographic process which has better performance and holographic simplicity, in addition to being able to miniaturize holographic processes more than is currently possible in state of the art holography systems.

The inventors have discovered a method to improve image quality in holography and, for the first time, utilize lenses made from birefringent materials to advantageously split an incoming beam of either coherent or incoherent light into two coincident beams with different focal lengths that interfere with one another and thus create holograms free of electro-optical or pixelated devices. This discovery has many advantages over current methods to create holograms in which many components, including multiple lenses, other electro-optical devices, and/or beam paths are necessary to create holograms. The current invention provides a purely optical holographic process which has better performance and holographic simplicity, in addition to being able to miniaturize holographic processes more than is currently possible in state of the art holography systems.

An apparatus for producing a hologram of an object includes a light source that emits an incoherent electromagnetic wave toward the object, and a masking device configured to display a mask, receive the incoherent electromagnetic wave emitted toward the object, mask the received incoherent electromagnetic wave according to the displayed mask, and produce a masked electromagnetic wave. The apparatus also includes an image recording device configured to capture an image of the masked electromagnetic wave, and a processing device configured to convert the image of the masked electromagnetic wave into the hologram of the object. A method for producing a hologram of an object is also described.

An apparatus for producing a hologram of an object includes a light source that emits an incoherent electromagnetic wave toward the object, and a masking device configured to display a mask, receive the incoherent electromagnetic wave emitted toward the object, mask the received incoherent electromagnetic wave according to the displayed mask, and produce a masked electromagnetic wave. The apparatus also includes an image recording device configured to capture an image of the masked electromagnetic wave, and a processing device configured to convert the image of the masked electromagnetic wave into the hologram of the object. A method for producing a hologram of an object is also described.

A hologram recording device includes an image sensor and a light interference generator that is attached to an imaging surface of the image sensor. The light interference generator is configured to generate two light waves whose phases are different from each other from an incident object light, and the image sensor is configured to record interference fringes that are formed from the two light waves as a hologram. The light interference generator includes a first birefringent material, a phase shifter array configured to spatially divide a polarization component whose polarization direction is parallel to or orthogonal to an optic axis of the first birefringent material to change a phase difference in two or more ways, and a polarizer whose transmission axis is in a direction that is inclined with respect to the optic axis of the first birefringent material. The first birefringent material, phase shifter array, and polarizer are arranged in this order starting from a side of incidence of light.

A hologram recording device includes an image sensor and a light interference generator that is attached to an imaging surface of the image sensor. The light interference generator is configured to generate two light waves whose phases are different from each other from an incident object light, and the image sensor is configured to record interference fringes that are formed from the two light waves as a hologram. The light interference generator includes a first birefringent material, a phase shifter array configured to spatially divide a polarization component whose polarization direction is parallel to or orthogonal to an optic axis of the first birefringent material to change a phase difference in two or more ways, and a polarizer whose transmission axis is in a direction that is inclined with respect to the optic axis of the first birefringent material. The first birefringent material, phase shifter array, and polarizer are arranged in this order starting from a side of incidence of light.

An apparatus and method to produce a hologram of a cross-section of an object includes an electromagnetic radiation assembly configured to receive a received electromagnetic radiation, such as light, from the object. The electromagnetic radiation assembly is further configured to diffract the received electromagnetic radiation and transmit a diffracted electromagnetic radiation. An image capture assembly is configured to capture an image of the diffracted electromagnetic radiation and produce the hologram of the cross-section of the object from the captured image. The hologram of the cross-section includes information regarding a single cross-section of the object.

An apparatus and method to produce a hologram of a cross-section of an object includes an electromagnetic radiation assembly configured to receive a received electromagnetic radiation, such as light, from the object. The electromagnetic radiation assembly is further configured to diffract the received electromagnetic radiation and transmit a diffracted electromagnetic radiation. An image capture assembly is configured to capture an image of the diffracted electromagnetic radiation and produce the hologram of the cross-section of the object from the captured image. The hologram of the cross-section includes information regarding a single cross-section of the object.

A birefringent metasurface lens formed by an array of nanoposts generates different phase profiles for different incident electromagnetic waves of different polarization. A first polarization is focused at a first focal length, while a second polarization is focused at a second focal length. A variable phase retarder and a polarizer generate interference patterns for each phase difference between the two incident polarizations. The interference patterns are used to generate a hologram, allowing reconstruction of the image of an object.

A birefringent metasurface lens formed by an array of nanoposts generates different phase profiles for different incident electromagnetic waves of different polarization. A first polarization is focused at a first focal length, while a second polarization is focused at a second focal length. A variable phase retarder and a polarizer generate interference patterns for each phase difference between the two incident polarizations. The interference patterns are used to generate a hologram, allowing reconstruction of the image of an object.