Methods, apparatus, devices, and systems for displaying three-dimensional objects by individually diffracting different colors of light are provided. In one aspect, an optical device includes: a first optically diffractive component including a first diffractive structure configured to diffract a first color of light having a first incident angle at a first diffracted angle, a second optically diffractive component including a second diffractive structure configured to diffract a second color of light having a second incident angle at a second diffracted angle, a first reflective layer configured to totally reflect the first color of light having the first incident angle and transmit the second color of light, and a second reflective layer configured to totally reflect the second color of light having the second incident angle. The first reflective layer is between the first and second diffractive structures, and the second diffractive structure is between the first and second reflective layers.

Methods, apparatus, devices, and systems for displaying three-dimensional objects by individually diffracting different colors of light are provided. In one aspect, a system includes a display having a plurality of display elements and an optical device configured to diffract a plurality of different colors of light to the display. The optical device is configured such that, when the plurality of different colors of light is incident on the optical device, the optical device separates light of individual colors of the different colors while suppressing crosstalk between the different colors.

A display apparatus includes a coherent light source, a display unit, a light-diffusing element, and at least one optical element. The coherent light source is configured to provide coherent light beams. The display unit is configured to form a three-dimensional image beam based on interference of the coherent light beams, wherein the three-dimensional image beam is imaged on an intermediate imaging surface after passing through the display unit. The light-diffusing element is located on the intermediate imaging surface, wherein a diffusion angle of the three-dimensional image beam is sequentially changed by passing through the light-diffusing element. The at least one optical element is located on a transmission path of the three-dimensional image beam from the light-diffusing element, and is configured to project the three-dimensional image light beam passing through the display unit out of the display apparatus to display a three-dimensional image.

A system for displaying three dimensional (3D) images. The system includes a 3D display operating in a first state to display a 3D image by outputting light into a viewing space and operating in a second state in which the 3D image is not displayed. The system further includes a screen element positioned between the 3D display and the viewing space. The screen element reflects light from the viewing space to appear opaque to a viewer in the viewing space when the 3D display operates in the second state. The screen element transmits the light output by the 3D display, whereby the 3D display image is perceivable by the viewer in the viewing space. The screen element includes a sheet of mesh or netting material that transmits light output by the 3D display through its pores or openings and may be a planar sheet of scrim or tulle.

A holographic image display device according to one embodiment comprises: an image display unit on which a holographic image is displayed; and a spatial impression providing unit which forms a space surrounding the holographic image, and includes a transparent color material such that the space looks colored and the holographic image can be recognized from the outside.

A system for making a holographic medium for use in generating light patterns for eye tracking includes a light source configured to provide light and a beam splitter configured to separate the light into a first portion of the light and a second portion of the light that is spatially separated from the first portion of the light. The system also includes a first set of optical elements configured to transmit the first portion of the light for providing a first wide-field beam onto an optically recordable medium and one or more diffractive optical elements configured to receive the second portion of the light and project a plurality of separate light patterns onto the optically recordable medium for forming the holographic medium.

Systems and methods for waveguide displays with angularly varying optical power in accordance with various embodiments of the invention are illustrated. One embodiment includes a waveguide display including a source of image modulated light projected over a field of view, and a waveguide including at least one output grating with an optical prescription providing angularly varying optical power for focusing the field of view onto an external surface. In another embodiment, the at least one output grating includes at least one grating prescription providing a first focal length for focusing a first FOV portion onto a first area of the surface and a second focal length for focusing a second FOV portion onto a second area of the surface. In still another embodiment, the at least one output grating includes at least one grating prescription providing a continuously varying focal length across at least a portion of the FOV.

An illumination apparatus that illuminates an illumination zone having a first direction and a second direction crossing the first direction is provided with a light source to emit a coherent light beam, and a diffraction optical device to diffract the coherent light beam incident from the light source. The diffraction optical device diffracts the incident coherent light beam so that a width of the illumination zone in the second direction gradually becomes wider along the first direction of the illumination zone from a nearer side to the diffraction optical device.

An eye-tracking system includes a holographic illuminator and a detector. The holographic illuminator includes a light source configured to provide light and a holographic medium optically coupled with the light source. The holographic medium is configured to receive the light provided from the light source and concurrently project a plurality of separate light patterns toward an eye. The detector is configured to detect a reflection of at least a subset of the plurality of separate light patterns, reflected off the eye, for determining a location of a pupil of the eye. Also disclosed is a method for determining a location of a pupil of an eye with the eye-tracking system that includes the holographic illuminator.

A system for displaying three dimensional (3D) images. The system includes a 3D display operating in a first state to display a 3D image by outputting light into a viewing space and operating in a second state in which the 3D image is not displayed. The system further includes a screen element positioned between the 3D display and the viewing space. The screen element reflects light from the viewing space to appear opaque to a viewer in the viewing space when the 3D display operates in the second state. The screen element transmits the light output by the 3D display, whereby the 3D display image is perceivable by the viewer in the viewing space. The screen element includes a sheet of mesh or netting material that transmits light output by the 3D display through its pores or openings and may be a planar sheet of scrim or tulle.