The present disclosure provides an optical modulation device, an optical modulation method and a holographic display apparatus. The optical modulation device is configured to perform optical modulation of a light beam and comprising: an amplitude modulator, configured to perform amplitude modulation of the light beam based on amplitude information in complex amplitude information of each pixel of a digital hologram; an optical scanning assembly, configured to scan the light beam within a predetermined range; a phase modulator, configured to perform phase modulation of the light beam based on phase information in the complex amplitude information.

The present disclosure provides an optical modulation device, an optical modulation method and a holographic display apparatus. The optical modulation device is configured to perform optical modulation of a light beam and comprising: an amplitude modulator, configured to perform amplitude modulation of the light beam based on amplitude information in complex amplitude information of each pixel of a digital hologram; an optical scanning assembly, configured to scan the light beam within a predetermined range; a phase modulator, configured to perform phase modulation of the light beam based on phase information in the complex amplitude information.

A holographic display device is provided, comprising a spatial light modulator. The spatial light modulator is configured to load at least one composite hologram, and one of the at least one composite hologram is formed by superposing N sub-holograms. The holographic display device further comprises a light source arranged on a light incoming side of the spatial light modulator. The light source is configured to provide readout light to the spatial light modulator. The light source comprises M light source components. The direction of propagation of emergent light of each of at least two light source components among the M light source components is identical to the direction of propagation of a reference wave corresponding to one of the N sub-holograms, wherein MN2, and M and N are positive integers.

A holographic display device is provided, comprising a spatial light modulator. The spatial light modulator is configured to load at least one composite hologram, and one of the at least one composite hologram is formed by superposing N sub-holograms. The holographic display device further comprises a light source arranged on a light incoming side of the spatial light modulator. The light source is configured to provide readout light to the spatial light modulator. The light source comprises M light source components. The direction of propagation of emergent light of each of at least two light source components among the M light source components is identical to the direction of propagation of a reference wave corresponding to one of the N sub-holograms, wherein MN2, and M and N are positive integers.

A copying device for generating a replication hologram that represents a copy of a master hologram. The device includes an object hologram for generating an object wave via a master signal, and a reference hologram for generating a reference wave with the aid of the master signal.

A copying device for generating a replication hologram that represents a copy of a master hologram. The device includes an object hologram for generating an object wave via a master signal, and a reference hologram for generating a reference wave with the aid of the master signal.

An apparatus for in-line holographic imaging is disclosed. In one aspect, the apparatus includes at least a first light source and a second light source arranged for illuminating an object arranged in the apparatus with a light beam. The apparatus also includes an image sensor arranged to detect at least a first and a second interference pattern, wherein the first interference pattern is formed when the object is illuminated by the first light source and the second interference pattern is formed when the object is illuminated by the second light source. The first and second interference patterns are formed by diffracted light, being scattered by the object, and undiffracted light of the light beam. The at least first and second light sources are arranged at different angles in relation to the object, and possibly illuminate the object using different wavelengths.

An apparatus for in-line holographic imaging is disclosed. In one aspect, the apparatus includes at least a first light source and a second light source arranged for illuminating an object arranged in the apparatus with a light beam. The apparatus also includes an image sensor arranged to detect at least a first and a second interference pattern, wherein the first interference pattern is formed when the object is illuminated by the first light source and the second interference pattern is formed when the object is illuminated by the second light source. The first and second interference patterns are formed by diffracted light, being scattered by the object, and undiffracted light of the light beam. The at least first and second light sources are arranged at different angles in relation to the object, and possibly illuminate the object using different wavelengths.

A holographic display method includes calculating a hologram, displaying it on a spatial light modulator (SLM) and illuminating it with coherent light. The hologram includes hologram pixels each having a hologram pixel value. The hologram is calculated using steps including: performing the inverse Fourier transform of the product of an object field and a negative quadratic phase exponential representative of positive optical power; and restricting each calculated hologram pixel value to one of a plurality (greater than two) of allowable pixel values to form a constrained hologram, which is displayed on the SLM. Each light-modulating pixel of the SLM is operable in a plurality of light-modulation levels corresponding to the plurality of allowable pixel values. The SLM is illuminated with coherent light to form a replay field including conjugate images: a real holographic reconstruction and a virtual holographic reconstruction having greater intensity than that of the real holographic reconstruction.

A holographic display method includes calculating a hologram, displaying it on a spatial light modulator (SLM) and illuminating it with coherent light. The hologram includes hologram pixels each having a hologram pixel value. The hologram is calculated using steps including: performing the inverse Fourier transform of the product of an object field and a negative quadratic phase exponential representative of positive optical power; and restricting each calculated hologram pixel value to one of a plurality (greater than two) of allowable pixel values to form a constrained hologram, which is displayed on the SLM. Each light-modulating pixel of the SLM is operable in a plurality of light-modulation levels corresponding to the plurality of allowable pixel values. The SLM is illuminated with coherent light to form a replay field including conjugate images: a real holographic reconstruction and a virtual holographic reconstruction having greater intensity than that of the real holographic reconstruction.