Abstract: A pupil-replicating waveguide suitable for operation with a coherent light source is disclosed. A waveguide body has opposed surfaces for guiding a beam of image light. An out-coupling element is disposed in an optical path of the beam for out-coupling portions of the beam at a plurality of spaced apart locations along the optical path. Electrodes are coupled to at least a portion of the waveguide body for modulating an optical path length of the optical path of the beam to create time-varying phase delays between the portions of the beam out-coupled by the out-coupling element.

Abstract: A layered optical element includes a substrate layer, an electrode layer disposed on the substrate layer, a liquid crystal (LC) layer comprising LC molecules, and a nanopatterned alignment layer in physical contact with the LC layer and disposed on a surface of either the substrate layer or the electrode layer. The nanopatterned alignment layer includes an arrangement of nanostructures, e.g., a grouping of nanolines. For a subset of the grouping of nanolines, the nanolines are configured to orient the LC molecules along a varying local orientation direction of each of nanoline in the subset. The varying local orientation direction of each nanoline in the subset can vary along a length of each nanoline.

Abstract: A pupil replication waveguide for a projector display includes a slab of transparent material for propagating display light in the slab via total internal reflection. A diffraction grating is supported by the slab. The diffraction grating includes a plurality of tapered slanted fringes in a substrate for out-coupling the display light from the slab by diffraction into a blazed diffraction order. A greater portion of the display light is out-coupled into the blazed diffraction order, and a smaller portion of the display light is out-coupled into a non-blazed diffraction order. The tapered fringes result in the duty cycle of the diffraction grating varying along the thickness direction of the diffraction grating, to facilitate suppressing the portion of the display light out-coupled into the non-blazed diffraction order.

Abstract: 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.

Abstract: Ion implantation is used to fabricate an optical device having a varying refractive index. The optical device can include a substrate with a material disposed on the substrate. A refractive index of the material is changed by ion implantation. The material can also be etched or imprinted. The optical device can be used in a virtual-reality system or augmented-reality system to provide angular selectivity from a display to a user's eye.

Abstract: A surface-relief structure comprises a surface-relief grating including a first material characterized by a first refractive index, a first layer of a second material having a second refractive index conformally deposited on surfaces of the surface-relief grating, and a second layer of a third material having a third refractive index conformally deposited on the first layer. The effective refractive index of the combination of the first layer and the second layer is less than, equal to, or greater than the first refractive index, thereby increasing the duty cycle and/or modifying the overall refractive index of the surface-relief structure. The first layer and the second layer are deposited using, for example, atomic layer deposition techniques.

Abstract: A surface-relief grating comprises a plurality of grating ridges including a first material, and a layer of a second material conformally deposited on surfaces of the plurality of grating ridges. A first region of the surface-relief grating is characterized by a first grating depth and a first duty cycle greater than a first threshold value. A second region of the surface-relief grating is characterized by a second grating depth and a second duty cycle lower than a second threshold value that is lower than the first threshold value. A difference between the first grating depth and the second grating depth is less than 20% of the second grating depth.

Abstract: A waveguide includes an input area, a multi-layered substrate, and an output area. The multi-layered substrate includes a plurality of layers of at least a substrate and at least one partially reflective layers. The input area in-couples light in a first band into the waveguide. The one or more partially reflective layers are partially reflective to light in the first band. Each of the one or more partially reflective layers are located between respective layers of the plurality of layers of the substrate. The output area out-couples light from the waveguide. The pupil replication density of the out-coupled light is based in part on a number of the one or more partially reflective layers and respective locations of the one or more partially reflective layers in the waveguide.

Abstract: A waveguide display includes a substrate having two opposite surfaces, and a slanted grating at a first surface of the two opposite surfaces of the substrate. The slanted grating includes a plurality of ridges and is characterized by a grating period in one direction. The plurality of ridges is tilted at a slant angle with respect to a surface normal of the first surface and is characterized by a height. The height of the plurality of ridges, the grating period, and the slant angle are configured to cause destructive interference between ambient light diffracted by the slanted grating. In some embodiments, a difference between the height of the plurality of ridges and an integer multiple of the grating period divided by the tangent of the slant angle is less than a threshold value.

Abstract: A pupil replication waveguide for a projector display includes a slab of transparent material for propagating display light in the slab via total internal reflection. A diffraction grating is supported by the slab. The diffraction grating includes a plurality of slanted fringes in a substrate for out-coupling the display light from the slab by diffraction into a blazed diffraction order. A greater portion of the display light is out-coupled into the blazed diffraction order, and a smaller portion of the display light is out-coupled into a non-blazed diffraction order. A refractive index contrast profile of the diffraction grating along a thickness direction of the diffraction grating is symmetrical, and a refractive index contrast is larger at a middle than at both sides of the refractive index contrast profile, whereby the portion of the display light out-coupled into the non-blazed diffraction order is decreased.

Abstract: Techniques for eye-tracking in a near-eye display system are disclosed. One example of a near-eye display system includes a substrate transparent to visible light and configured to be placed in front of a user's eye, one or more light sources configured to emit illumination light invisible to the user's eye, one or more input couplers configured to couple the illumination light into the substrate, and one or more grating couplers each configured to couple a portion of the illumination light out of the substrate and towards the user's eye at a different direction. The illumination light coupled into the substrate propagates within the substrate through total internal reflection. The one or more grating couplers include at least one of a chirped surface-relief grating coupler or a volume Bragg grating coupler.

Abstract: A three-dimensional diffraction grating is generated by selective deposition and/or selective etching. The three-dimensional diffraction grating includes a substrate and a plurality of structures located at different positions on the substrate. The structures have different materials. Edges of at least some of the structures are aligned. The three-dimensional diffraction grating includes different materials and aligned edges in all three dimensions. With the different materials and aligned edges, the three-dimensional diffraction gratings is configured to eliminate display artifacts, such as ghost, rainbow, etc.

Abstract: An inkjet is used to fabricate an optical device having a varying refractive index. The inkjet deposits a first material having a first refractive index and a second material having a second refractive index in a pattern on a substrate. The first material and/or the second material are processed to form an optical device having a refractive index that varies in one or two dimensions. The optical device is used in a virtual-reality system or augmented-reality system to provide angular selectivity from display to a user's eye.

Abstract: A nano-structure includes an outer area at an edge of the nano-structure. A width of the outer area defined by a distance from the edge of the nano-structure is less than 100 ?m. A depth of the nano-structure in the outer area changes gradually between 0% and at least 50% of a maximum depth of the nano-structure. A method includes forming an etch mask on a substrate and etching the substrate with the etch mask using an ion beam to form a nano-structure in the substrate. The etch mask includes an outer area near an edge of the etch mask. A width of the outer area defined by a distance from the edge of the etch mask is less than 100 ?m. A duty cycle of the etch mask in the outer area changes gradually between at least 10% and at least 90%.

Abstract: A manufacturing system performs a deposition of an etch-compatible film over a substrate. The etch-compatible film includes a first surface and a second surface opposite to the first surface. The manufacturing system performs a partial removal of the etch-compatible film to create a surface profile on the first surface with a plurality of depths relative to the substrate. The manufacturing system performs a deposition of a second material over the profile created in the etch-compatible film. The manufacturing system performs a planarization of the second material to obtain a plurality of etch heights of the second material in accordance with the plurality of depths in the profile created in the etch-compatible film. The manufacturing system performs a lithographic patterning of a photoresist deposited over the planarized second material to obtain the plurality of etch heights and one or more duty cycles in the second material.

Abstract: A nano-structure includes an outer area at an edge of the nano-structure. A width of the outer area defined by a distance from the edge of the nano-structure is less than 100 ?m. A depth of the nano-structure in the outer area changes gradually between 0% and at least 50% of a maximum depth of the nano-structure. A method includes forming an etch mask on a substrate and etching the substrate with the etch mask using an ion beam to form a nano-structure in the substrate. The etch mask includes an outer area near an edge of the etch mask. A width of the outer area defined by a distance from the edge of the etch mask is less than 100 ?m. A duty cycle of the etch mask in the outer area changes gradually between at least 10% and at least 90%.

Abstract: A pupil-replicating waveguide suitable for operation with a coherent light source is disclosed. A waveguide body has opposed surfaces for guiding a beam of image light. An out-coupling element is disposed in an optical path of the beam for out-coupling portions of the beam at a plurality of spaced apart locations along the optical path. Electrodes are coupled to at least a portion of the waveguide body for modulating an optical path length of the optical path of the beam to create time-varying phase delays between the portions of the beam out-coupled by the out-coupling element.

Abstract: A diffraction grating includes a substrate and an array of triangular ridges extending from the substrate. The ridges run parallel to one another and have triangular cross-sections such that first sides of the ridges face in a first direction and adjacent second sides of the ridges face in a second, different direction. An array of grating lines is disposed over the first sides of the array of ridges, each grating line of the array of grating lines comprising a slab of transparent material supported by the first side of a corresponding ridge of the array of ridges. A refractive index of the array of grating lines is different from a refractive index of the array of ridges.

Abstract: A waveguide display includes a first substrate and one or more grating layers on a first surface of the first substrate. The one or more grating layers are configured to cause destructive interference between ambient light diffracted by at least two grating layers or between ambient light diffracted by different portions of one grating layer. In some embodiments, the waveguide display also includes an angular-selective transmissive layer. The angular-selective transmissive layer is configured to reflect, diffract, or absorb ambient light incident on the angular-selective reflective layer with an incidence angle greater than a threshold value.

Abstract: An apparatus may include a projector that switches from emitting monochromatic light of a first color to emitting monochromatic light of a second color that is different from the first color. The apparatus may also include one or more variable-pitch diffraction gratings that diffract monochromatic light emitted from the projector. The apparatus may further include a controller that changes a pitch of at least one of the one or more variable-pitch diffraction gratings from a first pitch used when the projector is emitting monochromatic light of the first color to a second pitch used when the projector is emitting monochromatic light of the second color.