A printing device (106) includes a laser source and a LCOS-SLM (Liquid Crystal on Silicon Spatial Light Modulator). The printing device generates a laser control signal and a LCOS-SLM control signal. The laser source (110) generates a plurality of incident laser beams based on the laser control signal. The LCOS-SLM (112) receives the plurality of incident laser beams, modulates the plurality of incident laser beams based on the LCOS-SLM control signal to generate a plurality of holographic wavefronts (214,216) from the modulated plurality of incident laser beams. Each holographic wavefront forms at least one corresponding focal point. The printing device cures a surface layer or sub-surface layer (406) of a target material (206) at interference points of focal points of the plurality of holographic wavefronts. The cured surface layer of the target material forms a three-dimensional printed content.

A pseudo speckle pattern generation apparatus includes a light source, a beam expander, and a spatial light modulator. The spatial light modulator has an intensity modulation distribution based on a pseudo speckle pattern calculated from a pseudo random number pattern and a correlation function, receives light output from the light source and increased in beam diameter by the beam expander, spatially modulates the received light according to the modulation distribution, and outputs modulated light.

An interference imaging device includes a light interference generator that includes: a light wave splitter configured to reflect a part of incident light and to allow a remaining part of the incident light to pass through; a phase modulator configured to modulate a phase of incident light that has passed through the light wave splitter; and a reflector configured to reflect the phase-modulated incident light from the phase modulator so that the reflected, phase-modulated incident light overlaps with incident light that has been reflected by the light wave splitter.

An apparatus and method for recording a holographic optical element. The apparatus includes a first recording unit configured to provide a first wave front for recording the holographic optical element, a second recording unit configured to provide a second wave front for recording the holographic optical element, and (i) a deformable phase plate configured to perform wave front modulation of the first wave front when the holographic optical element is recorded, or (ii) a plurality of deformable phase plates, at least one deformable phase plate (of the plurality of deformable phase plates can be configured to perform wave front modulation of the first wave front when the holographic optical element is recorded.

A holographic display apparatus including a freeform curved surface and an operating method of the holographic display apparatus are provided. The holographic display apparatus includes: an image generator configured to generate a hologram image by modulating light; an optical system including a freeform curved surface for forming the hologram image generated by the image generator in a predetermined depth; and a processor configured to generate a computer-generated hologram (CGH) based on three-dimensional image information by using a phase map including information about an optical aberration with respect to the freeform curved surface and to control the image generator to modulate the light based on the CGH.

A holographic microscope configured to observe a sample is provided. The holographic microscope includes a light source, a light splitting element, a polarizing element, a phase modulation element, a light combining element, and a photosensitive element. The light source is configured to provide an illumination beam. The illuminating beam is transmitted through the light splitting element to form a first light beam and a second light beam, and the sample is disposed on a transmission path of the first light beam. The polarizing element and the phase modulation element are disposed on the transmission path of the first light beam or the second light beam. The first light beam and the second light beam are transmitted to the light combining element to form an interference beam. The photosensitive element is disposed on a transmission path of the interference beam to receive the interference beam to generate an optical signal.

A display system (300) comprising an optical system and a processing system. The optical system comprising a spatial light modulator (380), a light source, a Fourier transform lens, a viewing system (320, 330) and a processing system. The spatial light modulator is arranged to display holographic data in the Fourier domain, illuminated by the light source. The Fourier transform lens is arranged to produce a 2D holographic reconstruction in the spatial domain (310) corresponding to the holographic data. The viewing system is arranged to produce a virtual image (350) of the 2D holographic reconstruction. The processing system is arranged to combine the Fourier domain data representative of a 2D image with Fourier domain data representative of a phase only lens to produce first holographic data, and provide the first holographic data to the optical system to produce a virtual image.

Projection displays include a highlight projector and a main projector. Highlights projected by the highlight projector boost luminance in highlight areas of a base image projected by the main projector. Various highlight projectors are based on steerable beams, holographic projectors, and spatial light modulators. A Fourier transform component and a mask positioned on the Fourier plane thereof are used to attenuate or eliminate selected spatial frequencies, e.g., to increase peak luminance without raising the black level of the projected image.

An optical assembly is provided for use in holographic display of a replay image. The optical assembly may be of particular use is an augmented reality headset. The optical assembly includes a light-modulation element arranged to be illuminated off-axis by a light beam. The light-modulation element modulates the incident light to generate a replay image and generates a zero-order light beam. A focusing system is arranged after the light-modulation element. A light remover is positioned after the focussing system and is configured to remove the zero-order light beam from the light focussed by the focussing system. The focussing system is configured to focus zero-order light from the light-modulation element in a first plane different from a second plane which is the plane of focus of parallel light of the replay image. The light remover removes the zero-order light in the first plane.

An optical assembly comprises a light source, a light-modulation element for modulating light from the light source, and a terminal optical element for directing modulated light from the optical assembly. Optical elements are provided to guide the light in a first path from the light source to the light-modulation element and to guide the modulated light in a second path from the light-modulation element to the terminal optical element. The first and second paths are of similar shape, for example a c-shape, and are arranged in a nested configuration.