Abstract: An electronic device may have a display system. The display system may include a waveguide, an input coupler, and a surface relief grating (SRG) structure. The SRG structure may be formed from a high-index material that includes titanium dioxide nanoparticles. To increase the refractive index of the high-index material, the ratio of the size of the nanoparticle core to the size of the capping layer may be increased. The high-index material may also include nanoparticles of different sizes to increase the packing density of the nanoparticles. The SRG structure may be depth modulated in a lateral direction to maximize efficiency. The SRG structure may include slanted ridges covered by an encapsulant. The SRG structure may include a blazed grating with ridges that are covered by a coating and encapsulated by an encapsulant.

Abstract: A display may include a waveguide and a surface relief grating (SRG) structure on the waveguide. The SRG structure may perform expand image light propagating in the waveguide. The SRG structure may also couple the expanded image light out of the waveguide and towards an eye box. The SRG structure may include at least first and second SRGs that expand the image light in opposite directions. The first SRG may couple the image light expanded by the second SRG out of the waveguide and the second SRG may couple the image light expanded by the first SRG out of the waveguide. Modulation functions may be used to vary the grating strengths of the SRGs in the SRG structure between brow and cheek regions of the SRG structure. Diffraction efficiency of the SRG structure may additionally or alternatively be varied between nasal and temple regions of the SRG structure.

Abstract: Provided are a diffraction grating device, a method of manufacturing the diffraction grating device, and an optical apparatus including the diffraction grating device. The diffraction grating device includes a diffraction grating arranged on a light reflection substrate. The diffraction grating includes a plurality of diffraction elements, each diffraction element from among the plurality of diffraction elements having a height that causes a destructive interference between first light rays reflected by a top surface therefore and second light rays reflected by a bottom surface thereof, the first and second light rays being incident on the top and bottom surfaces, respectively, at an incidence angle greater than 45°.

Abstract: Provided are a grating device, a screen including the grating device, a method of manufacturing the screen, and a display apparatus including the screen. The grating device includes a transparent substrate and a diffraction grating arranged on the transparent substrate, the diffraction grating includes a plurality of meta-diffraction patterns, and each meta-diffraction pattern has a curved shape with a center of curvature provided in a direction parallel to the substrate. The screen includes a first polarizer, a second polarizer arranged next to the first polarizer, and a diffraction grating that is transparent to polarized light that has passed through the second polarizer and reflects polarized light having a polarization direction perpendicular to the polarized light, wherein the diffraction grating includes a plurality of meta-diffraction patterns, each meta-diffraction pattern having a curved shape with a center of curvature positioned in a travelling direction of incident light.

Abstract: Provided are a grating device, a screen including the grating device, a method of manufacturing the screen, and a display apparatus including the screen. The grating device includes a transparent substrate and a diffraction grating arranged on the transparent substrate, the diffraction grating includes a plurality of meta-diffraction patterns, and each meta-diffraction pattern has a curved shape with a center of curvature provided in a direction parallel to the substrate. The screen includes a first polarizer, a second polarizer arranged next to the first polarizer, and a diffraction grating that is transparent to polarized light that has passed through the second polarizer and reflects polarized light having a polarization direction perpendicular to the polarized light, wherein the diffraction grating includes a plurality of meta-diffraction patterns, each meta-diffraction pattern having a curved shape with a center of curvature positioned in a travelling direction of incident light.

Abstract: Provided are a diffraction grating device, a method of manufacturing the diffraction grating device, and an optical apparatus including the diffraction grating device. The diffraction grating device includes a diffraction grating arranged on a light reflection substrate. The diffraction grating includes a plurality of diffraction elements, each diffraction element from among the plurality of diffraction elements having a height that causes a destructive interference between first light rays reflected by a top surface therefore and second light rays reflected by a bottom surface thereof, the first and second light rays being incident on the top and bottom surfaces, respectively, at an incidence angle greater than 45°.