Abstract: Passive optical devices and methods of assembly are described in which surface relief gratings are formed at wafer level for fine patterning and then transferred to an optically transparent layer as diced grating dies for final assembly and passive optical device singulation at either wafer level or panel level.

Abstract: An electronic device may include a waveguide that directs light to an eye box. The waveguide may include a diffractive grating structure. A projector may generate image light coupled into the waveguide by a first input coupler. A light source may generate supplemental light coupled into the waveguide by a second input coupler. The diffractive grating structure may couple the image light out of the waveguide within a central region of the field of view (FOV) of an eye box and may couple the supplemental light out of the waveguide at a location within a peripheral region of the FOV. The location may be outside of the central region by at least 10 degrees. A gaze tracking sensor may estimate a user's gaze direction at the eye box. A processor may wake or power down the projector responsive to the gaze direction overlapping the location for a predetermined time period.

Abstract: A display may include a waveguide, an input coupler having a first surface relief grating (SRG) in a substrate on the waveguide, a cross-coupler having a second SRG in the substrate, and an output coupler having a third SRG in the substrate. The display may direct light to an eye box. A capping layer may be disposed over the substrate. An anti-reflective coating may be disposed over the capping layer. Microstructures may be disposed in non-SRG regions of the substrate and may be non-diffractive at visible wavelengths. The microstructures may include grooves and may have a similar filling factor to the SRGs. This may cause portions of the capping layer over the microstructures to sink into the grooves, thereby providing the capping layer with a relatively uniform thickness across a lateral area of the waveguide, without the microstructures producing visible artifacts or interacting with the light.

Abstract: A display may include a waveguide that directs image light to an eye box. The waveguide may include an optical coupler that redirects and replicates the light. The coupler may include a surface relief grating (SRG). The SRG may have a pitch that varies continuously along an axis orthogonal its ridges. The pitch may vary sinusoidally, linearly, parabolically, or according to other continuous and differentiable functions of position along the axis. The SRG may diffract the light. Upon diffracting the light, the SRG may impart a phase to the light. The phase may vary continuously as a function of position along a first axis and may, if desired, vary continuously as a function of position along a second axis orthogonal to the first axis. The SRG may prevent formation of coherent light paths after replication, thereby maximizing the efficiency of the system.

Abstract: A display system may include a waveguide and at least one surface relief grating (SRG) structure. The SRG structure may include a plurality of ridges separated by a plurality of troughs. The SRG structure may include an anti-reflective layer to mitigate specular reflections off of the ridges. The anti-reflective layer may be formed above the ridges such that the ridges are interposed between the waveguide and the anti-reflective layer. In this type of arrangement, the anti-reflective layer may fill the troughs between the ridges or may be patterned to overlap the ridges without filing the troughs. The anti-reflective layer may be formed below the ridges such that the anti-reflective layer is interposed between the ridges and the waveguide. The SRG structure may include multiple anti-reflective layers. When multiple anti-reflective layers are included, the anti-reflective layers may have at least one differing property (e.g., material, number of layers, dimension).

Abstract: A display may include a waveguide and an optical coupler. The coupler may include one or more surface relief gratings (SRGs) in a substrate on the waveguide. The SRG(s) may have a central region and gradient lateral edges separating the central region from a non-diffractive region of the substrate. The SRG(s) may exhibit peak diffraction efficiency within the central region and may exhibit gradient diffraction efficiency across the gradient lateral edges from the central region to the non-diffractive region. The gradient diffraction efficiency may be produced by varying, across the gradient lateral edges, the amplitude of the SRG(s), the phase of the SRG(s), the duty cycle of the SRG(s), the blaze angle of the SRG(s), and/or the thickness of a high or low index coating layered over the SRG(s). This may serve to prevent the couplers from becoming undesirably visible and to minimize perturbation of replicated pupils.

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°.