An apparatus generates a coherent illumination beam. An embedded light-scattering apparatus in a transparent substrate illuminates a reflective optical element which is also embedded inside the same substrate. The reflective optical element is designed to provide a desired beam profile.

A holographic display device includes a backlight unit for emitting light and a spatial light modulator. The spatial light modulator includes a plurality of pixels and a color filter layer including a plurality of color filter groups. The pixels are arranged in a zigzag form and are configured to modulate at least one of the amplitude and phase of the light. Each of the color filter groups includes a first sub-group including a plurality of first color filters, a second sub-group including a plurality of second color filters, and a third sub-group including a plurality of third color filters, and each of the pixels is aligned with one of the first color filters, the second color filters, and the third color filters of the color filter layer.

Architecture and designs of modulating both amplitude and phase at the same time in spatial light modulation are described. According to one aspect of the present invention, light propagation is controlled in two different directions (e.g., 0 and 45 degrees) to perform both amplitude modulation and phase modulation at the same time in liquid crystals. In one embodiment, a mask is used to form a pattern, where the pattern includes an array of alignment cells or embossed microstructures, a first group of the cells are aligned in the first direction and a second group of the cells are aligned in the second direction. Depending on applications, two cells from the first group and the second group may correspond to a single pixel or two neighboring pixels, resulting in amplitude modulation and phase modulation within the pixel or within an array of pixels.

A liquid crystal on silicon spatial light modulator comprising an array of light-modulating pixels and a controller are disclosed. Each light-modulating pixel of the array comprises liquid crystal and is associated with a respective flip-flop. The controller receives a hologram of an image comprising a plurality of hologram pixels. Each hologram pixel comprises a respective n-bit hologram pixel value. The controller drives each light-modulating pixel in accordance with a respective hologram pixel value of the hologram. There is a one-to-n pixel correlation between the hologram and the light-modulating pixels. The flip-flops of each contiguous group of n light-modulating pixels are connected in series to form a shift register. During operation of the shift register, the n-bit hologram pixel value associated with each contiguous group of n light-modulating pixels is provided to each light-modulating pixel one bit at a time over the course of at least n clock cycles.

A holographic projector includes an illumination system arranged to illuminate a hologram displayed on the pixel area of a spatial light modulator to form a holographic wavefront, and further includes a waveguide including an input port arranged to receive the holographic wavefront and a pair of opposing surfaces arranged to waveguide the holographic wavefront. A first surface of the pair of opposing surfaces is partially reflective-transmissive such that a plurality of replicas of the holographic wavefront are emitted therefrom. The illumination system includes a light source arranged to emit diverging light and a first collimating lens arranged to collimate the light. The collimated light has a varying intensity profile, in at least one dimension. The illumination system is configured such that the pixel area is contained within an area delineated by the width of the intensity profile of the collimated light at half the maximum intensity of said intensity profile.

A method for displaying a hologram to a variable direction including using circuitry to determine a direction from a holographic projector to a viewer for projecting a hologram to a viewer, and projecting a hologram in the determined direction, in which the projecting the hologram includes reflecting from a same mirror as the determining the direction of the viewer, and the circuitry controls the projecting the hologram to a direction corrected for a difference in direction between a projecting unit and a tracking unit relative to the mirror. Related apparatus and methods are also described.

Provided is an optically addressable spatial light modulator (OASLM)-based holographic display and a method of operating the same. The display includes an addressing unit including a light source unit emitting a plurality of recording beams, a driving mirror array including driving mirrors that each reflect a recording beam incident thereon, and a mirror member array including mirror members that each obliquely reflect a recording beam incident thereon, in which each of the driving mirrors corresponds to one of the mirror members. The recording beams, which are transmitted by the addressing unit, are focused onto the OASLM by micro lenses of a lenslet array. The OASLM is optically addressed by the recording beams focused by the micro lenses of the lenslet array and thus modulates and diffracts a reproduction beam, incident thereon from a reproduction beam providing unit, and thus a holographic image is reproduced.

A holographic display (display) for a head-mounted display (HMD). The display includes a source configured to emit at least partially coherent light and a beam conditioner that conditions the light from the source into one or more beams of light. The display also includes one or more spatial light modulators configured to encode the one or more beams of light using a hologram of a virtual reality image. The display further includes an objective lens and a conversion lens. The objective lens is positioned to create an intermediate image at a Fourier plane, and the intermediate image is a Fourier transform of the hologram. The conversion lens performs a Fourier transform of the intermediate image to generate an output hologram. The conversion lens also magnifies a portion of the output hologram and directs the magnified portion of the output hologram to an exit pupil of the HMD.

A near-to-eye display device includes a spatial light modulator. The spatial light modulator modulates an illumination wave to create a virtual-scene wave that is steered to a useful portion of an exit pupil plane. Higher diffraction orders and noise beams are filtered out by the user's pupil acting as a spatial filter.

A holographic display (display) for a head-mounted display (HMD). The display includes a source configured to emit at least partially coherent light and a beam conditioner that conditions the light from the source into one or more beams of light. The display also includes one or more spatial light modulators configured to encode the one or more beams of light using a hologram of a virtual reality image. The display further includes an objective lens and a conversion lens. The objective lens is positioned to create an intermediate image at a Fourier plane, and the intermediate image is a Fourier transform of the hologram. The conversion lens performs a Fourier transform of the intermediate image to generate an output hologram. The conversion lens also magnifies a portion of the output hologram and directs the magnified portion of the output hologram to an exit pupil of the HMD.