Abstract: Diffraction gratings provide optical elements in head-mounted display systems to, e.g., incouple light into or outcouple light out of a waveguide. These diffraction gratings may be configured to have reduced polarization sensitivity. Such gratings may, for example, incouple or outcouple light of different polarizations, or polarized and unpolarized light, with a similar level of efficiency. The diffraction gratings and waveguides may include a transmissive layer and a metal layer. The diffraction grating may comprise a blazed grating.

Abstract: Methods are disclosed for fabricating molds for forming waveguides with integrated spacers for forming eyepieces. The molds are formed by etching features (e.g., 1 ?m to 1000 ?m deep) into a substrate comprising single crystalline material using an anisotropic wet etch. The etch masks for defining the large features may comprise a plurality of holes, wherein the size and shape of each hole at least partially determine the depth of the corresponding large feature. The holes may be aligned along a crystal axis of the substrate and the etching may automatically stop due to the crystal structure of the substrate. The patterned substrate may be utilized as a mold onto which a flowable polymer may be introduced and allowed to harden. Hardened polymer in the holes may form a waveguide with integrated spacers. The mold may be also used to fabricate a platform comprising a plurality of vertically extending microstructures of precise heights, to test the curvature or flatness of a sample, e.g.

Abstract: Blazed diffraction gratings provide optical elements in head-mounted display systems to, e.g., incouple light into or out-couple light out of a waveguide. These blazed diffraction gratings may be configured to have reduced polarization sensitivity. Such gratings may, for example, incouple or outcouple light of different polarizations with similar level of efficiency. The blazed diffraction gratings and waveguides may be formed in a high refractive index substrate such as lithium niobate. In some implementations, the blazed diffraction gratings may include diffractive features having a feature height of 40 nm to 120 nm, for example, 80 nm. The diffractive features may be etched into the high index substrate, e.g., lithium niobate.

Abstract: An imprint lithography method of configuring an optical layer includes selecting one or more parameters of a nanolayer to be applied to a substrate for changing an effective refractive index of the substrate and imprinting the nanolayer on the substrate to change the effective refractive index of the substrate such that a relative amount of light transmittable through the substrate is changed by a selected amount.

Abstract: Recesses are formed on a front side and a rear side of a waveguide. A solid porogen material is spun onto the front side and the rear side and fills the recesses. First front and rear cap layers are then formed on raised formations of the waveguide and on the solid porogen material. The entire structure is then heated and the solid porogen material decomposes to a porogen gas. The first front and rear cap layers are porous to allow the porogen gas to escape and air to enter into the recesses. The air maximizes a difference in refractive indices between the high-index transparent material of the waveguide and the air to promote reflection in the waveguide from interfaces between the waveguide and the air.

Abstract: An optical device, such as an eyepiece, including multiple layers of waveguides. The optical device can include an edge sealant for reducing light contamination, a lamination dam to restrict the wicking of the edge sealant between layers of the optical device, and venting gap(s) in the sealant and dam to allow air flow between the exterior and interior of the eyepiece. The gap(s) allow outgassing from the interior of the eyepiece of unreacted polymer and/or accumulated moisture, to prevent defect accumulation caused by chemical reaction of outgassed chemicals with the (e.g., ionic, acidic, etc.) surface of the eyepiece layers. The gap(s) also prevent pressure differences which may physically deform the eyepiece over time.

Abstract: Blazed diffraction gratings provide optical elements in head-mounted display systems to, e.g., incouple light into or out-couple light out of a waveguide. These blazed diffraction gratings may be configured to have reduced polarization sensitivity. Such gratings may, for example, incouple or outcouple light of different polarizations with similar level of efficiency. The blazed diffraction gratings and waveguides may be formed in a high refractive index substrate such as lithium niobate. In some implementations, the blazed diffraction gratings may include diffractive features having a feature height of 40 nm to 120 nm, for example, 80 nm. The diffractive features may be etched into the high index substrate, e.g., lithium niobate.

Abstract: Waveguides comprising materials with refractive index greater than or equal to 1.8 and methods of patterning waveguides are disclosed. Patterned waveguides comprising materials with refractive index greater than or equal to 1.8 can be incorporated in display devices, such as, for example wearable display devices to project virtual images to a viewer. A waveguide may be transparent and may comprise a substrate comprising a first material having a first refractive index greater than about 2.0. Diffractive features may be formed, on the substrate, of a second material having a second refractive index that is lower than the first refractive index. A third material may be disposed over the diffractive features and may have a third refractive index that is higher than the second refractive index.

Abstract: An imprint lithography method of configuring an optical layer includes selecting one or more parameters of a nanolayer to be applied to a substrate for changing an effective refractive index of the substrate and imprinting the nanolayer on the substrate to change the effective refractive index of the substrate such that a relative amount of light transmittable through the substrate is changed by a selected amount.

Abstract: Recesses are formed on a front side and a rear side of a waveguide. A solid porogen material is spun onto the front side and the rear side and fills the recesses. First front and rear cap layers are then formed on raised formations of the waveguide and on the solid porogen material. The entire structure is then heated and the solid porogen material decomposes to a porogen gas. The first front and rear cap layers are porous to allow the porogen gas to escape and air to enter into the recesses. The air maximizes a difference in refractive indices between the high-index transparent material of the waveguide and the air to promote reflection in the waveguide from interfaces between the waveguide and the air.

Abstract: An optical device, such as an eyepiece, including multiple layers of waveguides. The optical device can include an edge sealant for reducing light contamination, a lamination dam to restrict the wicking of the edge sealant between layers of the optical device, and venting gap(s) in the sealant and dam to allow air flow between the exterior and interior of the eyepiece. The gap(s) allow outgassing from the interior of the eyepiece of unreacted polymer and/or accumulated moisture, to prevent defect accumulation caused by chemical reaction of outgassed chemicals with the (e.g., ionic, acidic, etc.) surface of the eyepiece layers. The gap(s) also prevent pressure differences which may physically deform the eyepiece over time.

Abstract: Methods for creating a pattern on a curved surface and an optical structure (e.g., curved waveguide, a lens having an antireflective feature, an optical structure of a wearable head device) are disclosed. In some embodiments, the method comprises: depositing a patterning material on a curved surface; positioning a superstrate over the patterning material, the superstrate comprising a template for creating the pattern; applying, using the patterning material, a force between the curved surface and the superstrate; curing the patterning material, wherein the cured patterning material comprises the pattern; and removing the superstrate. In some embodiments, the method comprises forming the optical structure using the pattern.

Abstract: Disclosed herein are systems and methods for displays, such as for a head wearable device. An example display can include an infrared illumination layer, the infrared illumination layer including a waveguide having a first face and a second face, the first face disposed opposite the second face. The illumination layer may also include an in-coupling grating disposed on the first face, the in-coupling grating configured to couple light into the waveguide to generate internally reflected light propagating in a first direction. The illumination layer may also include a plurality of out-coupling gratings disposed on at least one of the first face and the second face, the plurality of out-coupling gratings configured to receive the internally reflected light and couple the internally reflected light out of the waveguide.

Abstract: Very high refractive index (n>2.2) lightguide substrates enable the production of 70° field of view eyepieces with all three color primaries in a single eyepiece layer. Disclosed herein are viewing optics assembly architectures that make use of such eyepieces to reduce size and cost, simplifying manufacturing and assembly, and better-accommodating novel microdisplay designs.

Abstract: An eyepiece waveguide includes a set of waveguide layers having a world side and a user side. The eyepiece waveguide also includes a first cover plate having a first optical power and disposed adjacent the world side of the set of waveguide layers and a second cover plate having a second optical power and disposed adjacent the user side of the set of waveguide layers.

Abstract: Waveguides comprising materials with refractive index greater than or equal to 1.8 and methods of patterning waveguides are disclosed. Patterned waveguides comprising materials with refractive index greater than or equal to 1.8 can be incorporated in display devices, such as, for example wearable display devices to project virtual images to a viewer.

Abstract: Very high refractive index (n>2.2) lightguide substrates enable the production of 70° field of view eyepieces with all three color primaries in a single eyepiece layer. Disclosed herein are viewing optics assembly architectures that make use of such eyepieces to reduce size and cost, simplifying manufacturing and assembly, and better-accommodating novel microdisplay designs.

Abstract: A method of fabricating a blazed diffraction grating comprises providing a master template substrate and imprinting periodically repeating lines on the master template substrate in a plurality of master template regions. In some embodiments, the periodically repeating lines in different ones of the master template regions extend in different directions. The method additionally comprises using at least one of the master template regions as a master template to imprint at least one blazed diffraction grating pattern on a grating substrate. In some embodiments, the method further comprises coating the periodically repeating lines with a material having a greater hardness than the material that forms the lines.

Abstract: A method of fabricating an optical element includes providing a substrate, forming a castable material coupled to the substrate, and casting the castable material using a mold. The method also includes curing the castable material and removing the mold. The optical element comprises a planar region and a clear aperture adjacent the planar region and characterized by an optical power.

Abstract: A method of fabricating a blazed diffraction grating comprises providing a master template substrate and imprinting periodically repeating lines on the master template substrate in a plurality of master template regions. The periodically repeating lines in different ones of the master template regions extend in different directions. The method additionally comprises using at least one of the master template regions as a master template to imprint at least one blazed diffraction grating pattern on a grating substrate.