Disclosed is a method for correcting an image, a storage medium, and a projection device. The method is applied to a projection device, the projection device including a grating and a light generation component. The method includes: determining, in a region in which a projection image projected by the projection device overlaps with a projected image projected through the grating by detection light output from the projection device, diffraction spots having a diameter not equal to a preset value as target diffraction spots; determining a group of target diffraction spots continuously arranged in a horizontal or vertical direction, as well as diffraction spots having a diameter equal to the preset value that are respectively located on both sides of the group of target diffraction spots, as a region to be corrected; determining an angle α.sub.i between a plane of an i.sup.th diffraction spot and a plane of an (i+1).sup.th diffraction spot that are adjacent in the horizontal or vertical direction in the region to be corrected; and determining a corrected projection length of the (i+1).sup.th diffraction spot according to the preset value and angles α.sub.1 to α.sub.i.

An electronic device may include a display that generates light for an optical system that redirects the light towards an eye box. The optical system may include a waveguide, a non-diffractive input coupler, a cross coupler, and an output coupler. The cross coupler may expand the light in a first direction. The cross coupler may perform an even number of diffractions on the light and may couple the light back into the waveguide at an angle suitable for total internal reflection. The output coupler may expand the light in a second direction while coupling the light out of the waveguide. The cross coupler may include surface relief gratings or holographic gratings embedded within the waveguide or formed in a separate substrate. The optical system may direct the light towards the eye box without chromatic dispersion and while supporting an expanded field of view and optical bandwidth.

The display device including a first diffraction optical element group, and a second diffraction optical element group, wherein the first diffraction optical element group is constituted by laminating a first diffraction optical element having a first interference pattern corresponding to a wavelength band of one or two of three colors of red, green, and blue of the image light, and a second diffraction optical element having a second interference pattern corresponding to a wavelength band of remaining colors of the three colors, and the second diffraction optical element group is constituted by laminating a third diffraction optical element having a third interference pattern corresponding to a wavelength band of one or two of three colors of red, green, and blue of the image light, and a fourth diffraction optical element having a fourth interference pattern corresponding to a wavelength band of remaining colors of the three colors.

An array of optical resonators comprises at least a first type of optical resonators each having a resonant response to an optical field at a first wavelength, and a second type of optical resonators each having a resonant response to an optical field at a second wavelength, being different from the first wavelength. The resonant responses can be selected to reduce chromatic aberrations, or to shape a profile of a light beam, or to selectively switch a near field beam.

A phase-adjusting element configured to provide substantially liquid-invariant extended depth of field for an associated optical lens. One example of a lens incorporating the phase-adjusting element includes the lens having surface with a modulated relief defining a plurality of regions including a first region and a second region, the first region having a depth relative to the second region, and a plurality of nanostructures formed in the first region. The depth of the first region and a spacing between adjacent nanostructures of the plurality of nanostructures is selected to provide a selected average index of refraction of the first region, and the spacing between adjacent nanostructures of the plurality of nanostructures is sufficiently small that the first region does not substantially diffract visible light.

A phase-adjusting element configured to provide substantially liquid-invariant extended depth of field for an associated optical lens. One example of a lens incorporating the phase-adjusting element includes the lens having surface with a modulated relief defining a plurality of regions including a first region and a second region, the first region having a depth relative to the second region, and a plurality of nanostructures formed in the first region. The depth of the first region and a spacing between adjacent nanostructures of the plurality of nanostructures is selected to provide a selected average index of refraction of the first region, and the spacing between adjacent nanostructures of the plurality of nanostructures is sufficiently small that the first region does not substantially diffract visible light.

A display module includes an image light generation device configured to generate image light, a first diffraction element including a first surface and a second surface and configured to diffract the image light, a first reflection section configured to reflect the image light, and a second diffraction element including a third surface and configured to diffract the image light. The first diffraction element is configured to transmit the image light incident on the first surface and emit the image light toward the first reflection section, the first reflection section is configured to reflect the image light toward the second surface, the first diffraction element is configured to diffract the image light incident on the second surface and emit the image light toward the second diffraction element, and the second diffraction element is configured to diffract the image light, emit the image light, and form an exit pupil.

The present disclosure provides a method and apparatus for generating a full-color holographic image. The method of generating a full-color holographic image includes forming images for each color channel based on complex hologram data extracted from rays propagating from a target object, and combining the formed images into one color image, wherein the images for each color channel are formed at reconstruction points for each color channel derived based on the complex hologram data.

A device for a 3D measurement of object coordinates of a measurement object or parts of the measurement object in a coordinate measuring machine is provided. The device includes at least one illumination device configured to generate at least one illumination light beam and to illuminate the measurement object, at least one lens, wherein the lens has a longitudinal chromatic aberration, at least one color sensor arranged in an image plane of the lens, wherein the color sensor is configured to capture a measurement light beam generated by the measurement object in response to the illumination light beam and to determine at least one spectrally dependent image space content; at least one evaluation unit configured to determine at least one item of depth information from the spectrally dependent image space content.

A multilayer grating is a diffraction grating that includes a plurality of layers. The plurality of layers arranged to form a 2-dimensional grating, the layers including at least a first patterned layer and a second patterned layer. The first patterned layer includes a plurality of different materials that are arranged in a first pattern such that the first patterned layer has a first index profile. The second patterned layer includes a plurality of different materials that are arranged in a second pattern such that the second patterned layer has a second index profile that is inverted relative to the first index profile. Ambient light incident on the first patterned layer and the second patterned layer creates a first diffracted ray and a second diffracted ray, respectively, and the first diffracted ray and the second diffracted ray destructively interfere with each other based in part on the inverted index profile.