Methods, apparatus, devices, and systems for reconstructing three-dimensional objects with display zero order light suppression are provided. In one aspect, a method includes illuminating a display with light, a portion of the light illuminating display elements of the display, and modulating the display elements of the display with a hologram corresponding to holographic data to diffract the portion of the light to form a holographic scene corresponding to the holographic data, and to suppress display zero order light in the holographic scene. The display zero order light can include reflected light from the display.

Methods, apparatus, devices, and systems for reconstructing three-dimensional objects with display zero order light suppression are provided. In one aspect, a method includes illuminating a display with light at an incident angle, a portion of the light illuminating display elements of the display, modulating the display elements of the display with a hologram corresponding to holographic data to diffract the portion of the light to form a holographic scene corresponding to the holographic data, and redirecting display zero order light away from the holographic scene to suppress the display zero order light in the holographic scene. The display zero order light includes reflected light from the display.

Methods, apparatus, devices, and systems for reconstructing three-dimensional objects with display zero order light suppression are provided. In one aspect, a method includes illuminating a display with light at an incident angle, a portion of the light illuminating display elements of the display, modulating the display elements of the display with a hologram corresponding to holographic data to diffract the portion of the light to form a holographic scene corresponding to the holographic data, and redirecting display zero order light away from the holographic scene to suppress the display zero order light in the holographic scene. The display zero order light includes reflected light from the display. The light includes a plurality of different colors of light.

An illumination device for illuminating a spatial light modulator device. Sub-holograms are used for encoding a hologram into the spatial light modulator device. The Illumination device includes at least one light source for emitting light for illuminating the spatial light modulator device and a beam shaping unit. The beam shaping unit provides a flat-top plateau-type distribution of an absolute value of a complex degree of mutual coherence of the light in a plane of the spatial light modulator device to be illuminated. The flat-top plateau-type distribution of the absolute value of the complex degree of mutual coherence has a shape that is at least similar to a shape of the largest sub-hologram used for encoding of object points into the spatial light modulator device.

There is provided a holographic projector comprising a hologram engine and a controller. The hologram engine is arranged to provide a hologram comprising a plurality of hologram pixels. Each hologram pixel has a respective hologram pixel value. The controller is arranged to selectively-drive a plurality of light-modulating pixels so as to display the hologram. Displaying the hologram comprises displaying each hologram pixel value on a contiguous group of light-modulating pixels of the plurality of light-modulating pixels such that there is a one-to-many pixel correlation between the hologram and the plurality of light-modulating pixels.

Provided is an optical device including a first backlight configured to output first light of a first wavelength through a first output coupler, a first lens disposed to face the first output coupler and having a focal length with respect to the first light, a second backlight including a second output coupler, the second backlight being configured to output second light of a second wavelength through the second output coupler, a second lens disposed to face the second output coupler and having different focal lengths with respect to the first light and the second light, a third backlight including a third output coupler, the third backlight being configured to output third light of a third wavelength through the third output coupler, and a third lens disposed to face the third output coupler and having different focal lengths with respect to the first light, the second light, and the third light.

A replicator assembly includes reflective, transmissive, and transparent elements. The reflective element receives and reflects a hologram of a HUD system. The transmissive element includes a partially transmissive portion that receives a reflection of the hologram from the reflective element, outputs N replications of the hologram, and reflects N−1 replications of the hologram. The partially transmissive portion is implemented as a continuous transmission neutral density filter across different phase regions. The phase regions of the partially transmissive portion correspond respectively to the N replications. N is an integer greater than or equal to 2. The reflective element reflects the N−1 replications of the hologram. The transparent element is disposed between the reflective and transmissive elements and guides the N replications of the hologram between the reflective and transmissive elements. The reflective, transmissive and transparent elements are implemented as a replicator and collectively provide the N replications of the hologram.

A backlight unit may include: a light source providing coherent light; a light guide plate having a light entrance surface on which light from the light source is incident and a light exit surface through which the light is output; a plurality of diffraction gratings (for example, a first input grating, a second input grating, and a third input grating) that are arranged in different regions of the light guide plate to sequentially diffract the light from the light source such that that the beam width of the light may increase as the light propagates in the light guide plate; and a diffraction grating (for example, an output grating) that diffracts and outputs the light having an increased beam width in a direction toward the outside of the light guide plate.

A holographic display with a spatial light modulator coupled to a pupil-replicating lightguide is disclosed. The spatial light modulator provides a light beam with spatially modulated amplitude and/or phase. The light beam is replicated by the pupil-replicating lightguide into a plurality of portions. The portions interfere at an exit pupil to provide an image for direct observation by a user. An eye-tracking system may be provided to determine the position of the user pupils, and the spatial modulation of the light beam may be adjusted accordingly to make sure that the optical interference of the beam portions at the eye pupils provides the required image.

Methods, apparatus, devices, and systems for displaying three-dimensional objects by individually diffracting different colors of light are provided. In one aspect, an optically diffractive device includes: first and second diffractive components and a color-selective polarizer therebetween. The first diffractive component is configured to diffract a first color of light in a first polarization state incident at a first incident angle with a first diffraction efficiency at a first diffracted angle, and diffract a second color of light in a second polarization state with a diffraction efficiency substantially less than the first diffraction efficiency. The color-selective polarizer is configured to rotate the second polarization state of the second color of light to the first polarization state. The second diffractive component is configured to diffract the second color of light in the first polarization state with a second diffraction efficiency at a second diffracted angle substantially identical to the first diffracted angle.