This disclosure describes optical systems for projecting an irregular or complex pattern onto a region of space (e.g., a two-dimensional or three-dimensional object or scene). A respective light beam is emitted from each of a plurality of light sources. The emitted light beams collectively are diffracted in accordance with a plurality of different first grating parameters to produce a plurality of first diffracted light beams. The first diffracted light beams then collectively are diffracted in accordance with one or more second grating parameters.

This disclosure describes optical systems for projecting an irregular or complex pattern onto a region of space (e.g., a two-dimensional or three-dimensional object or scene). A respective light beam is emitted from each of a plurality of light sources. The emitted light beams collectively are diffracted in accordance with a plurality of different first grating parameters to produce a plurality of first diffracted light beams. The first diffracted light beams then collectively are diffracted in accordance with one or more second grating parameters.

Systems and methods for performing coherent diffraction in an optical device are disclosed. An optical device may include a grating medium with a first hologram having a first grating frequency. A second hologram at least partially overlapping the first hologram may be provided in the grating medium. The second hologram may have a second grating frequency that is different from the first grating frequency. The first and second holograms may be pair-wise coherent with each other. A manufacturing system may be provided that writes the pair-wise coherent holograms in a grating medium using a signal beam and a reference beam. Periscopes may redirect portions of the signal and reference beams towards a partial reflector, which combines the beams and provides the combined beam to a detector. A controller may adjust an effective path length difference between the signal and reference beams based on a measured interference pattern.

Systems and methods for performing coherent diffraction in an optical device are disclosed. An optical device may include a grating medium with a first hologram having a first grating frequency. A second hologram at least partially overlapping the first hologram may be provided in the grating medium. The second hologram may have a second grating frequency that is different from the first grating frequency. The first and second holograms may be pair-wise coherent with each other. A manufacturing system may be provided that writes the pair-wise coherent holograms in a grating medium using a signal beam and a reference beam. Periscopes may redirect portions of the signal and reference beams towards a partial reflector, which combines the beams and provides the combined beam to a detector. A controller may adjust an effective path length difference between the signal and reference beams based on a measured interference pattern.

A display apparatus capable of providing an expanded viewing window includes a light guide plate including an input coupler and an output coupler; and an image providing apparatus facing the input coupler to provide an image to the input coupler. The input coupler may include a plurality of sub input couplers configured to propagate the image provided from the image providing apparatus at different angles in the light guide plate.

A display apparatus capable of providing an expanded viewing window includes a light guide plate including an input coupler and an output coupler; and an image providing apparatus facing the input coupler to provide an image to the input coupler. The input coupler may include a plurality of sub input couplers configured to propagate the image provided from the image providing apparatus at different angles in the light guide plate.

A diffraction light guide plate capable of increasing the area of an output image without increasing the total size thereof and having an advantage that the pupil position of a user is not limited. The diffraction light guide plate comprises first and second diffraction optical elements, wherein the first diffraction optical element is an element capable of receiving light incident onto the first diffraction optical element and outputting the received light toward the second diffraction optical element, and the second diffraction optical element is an element capable of emitting light therefrom out of the incident light from the first diffraction optical element.

A diffraction light guide plate capable of increasing the area of an output image without increasing the total size thereof and having an advantage that the pupil position of a user is not limited. The diffraction light guide plate comprises first and second diffraction optical elements, wherein the first diffraction optical element is an element capable of receiving light incident onto the first diffraction optical element and outputting the received light toward the second diffraction optical element, and the second diffraction optical element is an element capable of emitting light therefrom out of the incident light from the first diffraction optical element.

A diffractive optical element includes a plurality of diffractive layers. The plurality of diffractive layers includes adjacent diffractive layers including a plurality of optical axes that change along in-plane rotation directions opposite to

A diffractive optical element includes a plurality of diffractive layers. The plurality of diffractive layers includes adjacent diffractive layers including a plurality of optical axes that change along in-plane rotation directions opposite to