Abstract: Systems and methods for improving robust layer separation during the separation process of an imprint lithography process are described. Included are methods of matching strains between a substrate to be imprinted and the template, varying or modifying the forces applied to the template and/or the substrate during separation, or varying or modifying the kinetics of the separation process.

Abstract: Embodiments of the present disclosure are directed to 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 darn to restrict the wicking of the edge sealant between layers of the optical device, and venting gap (s) in the sealant and darn 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: 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 includes a substrate and an in-coupling grating patterned on a single side of the substrate. A first grating coupler is patterned on the single side of the substrate and has a first grating pattern. The first grating coupler is optically coupled to the in-coupling grating. A second grating coupler is patterned on the single side of the substrate adjacent to the first grating coupler. The second grating coupler has a second grating pattern different from the first grating pattern. The second grating coupler is optically coupled to the in-coupling grating.

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: Display devices include waveguides with in-coupling optical elements that mitigate re-bounce of in-coupled light to improve overall in-coupling efficiency and/or uniformity. A waveguide receives light from a light source and/or projection optics and includes an in-coupling optical element that in-couples the received light to propagate by total internal reflection in a propagation direction within the waveguide. Once in-coupled into the waveguide the light may undergo re-bounce, in which the light reflects off a waveguide surface and, after the reflection, strikes the in-coupling optical element. Upon striking the in-coupling optical element, the light may be partially absorbed and/or out-coupled by the optical element, thereby effectively reducing the amount of in-coupled light propagating through the waveguide.

Abstract: An imprint lithography method of configuring an optical layer includes imprinting first features of a first order of magnitude in size on a side of a substrate with a patterning template, while imprinting second features of a second order of magnitude in size on the side of the substrate with the patterning template, the second features being sized and arranged to define a gap between the substrate and an adjacent surface.

Abstract: Embodiments of the present disclosure are directed to techniques for manufacturing an eyepiece (or eyepiece layer) by applying multiple, different diffraction gratings to a single side of an eyepiece substrate instead of applying different gratings to different sides (e.g., opposite surfaces) of the substrate. Embodiments are also directed to the eyepiece (or eyepiece layer) that is arranged to have multiple, different diffraction gratings on a single side of the eyepiece substrate. In some embodiments, two or more grating patterns are superimposed to create a combination pattern in a template (e.g., a master), which is then used to apply the combination pattern to a single side of the eyepiece substrate. In some embodiments, multiple layers of patterned material (e.g., with differing refraction indices) are applied to a single side of the substrate. In some examples, the combined grating patterns are orthogonal pupil expander and exit pupil expander grating patterns.

Abstract: Control of lateral strain and lateral strain ratio (dt/db) between template and substrate through the selection of template and/or substrate thicknesses (Tt and/or Tb), control of template and/or substrate back pressure (Pt and/or Pb), and/or selection of material stiffness are described.

Abstract: Techniques are described for using confinement structures and/or pattern gratings to reduce or prevent the wicking of sealant polymer (e.g., glue) into the optically active areas of a multi-layered optical assembly. A multi-layered optical structure may include multiple layers of substrate imprinted with waveguide grating patterns. The multiple layers may be secured using an edge adhesive, such as a resin, epoxy, glue, and so forth. A confinement structure such as an edge pattern may be imprinted along the edge of each layer to control and confine the capillary flow of the edge adhesive and prevent the edge adhesive from wicking into the functional waveguide grating patterns of the layers. Moreover, the edge adhesive may be carbon doped or otherwise blackened to reduce the reflection of light off the edge back into the interior of the layer, thus improving the optical function of the assembly.

Abstract: An eyepiece includes a substrate and an in-coupling grating patterned on a single side of the substrate. A first grating coupler is patterned on the single side of the substrate and has a first grating pattern. The first grating coupler is optically coupled to the in-coupling grating. A second grating coupler is patterned on the single side of the substrate adjacent to the first grating coupler. The second grating coupler has a second grating pattern different from the first grating pattern. The second grating coupler is optically coupled to the in-coupling grating.

Abstract: Methods and systems are provided for fabricating polymer-based imprint lithography templates having thin metallic or oxide coated patterning surfaces. Such templates show enhanced fluid spreading and filling (even in absence of purging gases), good release properties, and longevity of use. Methods and systems for fabricating oxide coated versions, in particular, can be performed under atmospheric pressure conditions, allowing for lower cost processing and enhanced throughput.

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: 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 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 diffraction gratings and waveguides may include a transmissive layer and a metal layer. The diffraction grating may comprises a blazed grating.

Abstract: Embodiments of the present disclosure are directed to techniques for manufacturing an eyepiece (or eyepiece layer) by applying multiple, different diffraction gratings to a single side of an eyepiece substrate instead of applying different gratings to different sides (e.g., opposite surfaces) of the substrate. Embodiments are also directed to the eyepiece (or eyepiece layer) that is arranged to have multiple, different diffraction gratings on a single side of the eyepiece substrate. In some embodiments, two or more grating patterns are superimposed to create a combination pattern in a template (e.g., a master), which is then used to apply the combination pattern to a single side of the eyepiece substrate. In some embodiments, multiple layers of patterned material (e.g., with differing refraction indices) are applied to a single side of the substrate. In some examples, the combined grating patterns are orthogonal pupil expander and exit pupil expander grating patterns.

Abstract: Micro- and nano-patterns in imprint layers formed on a substrate and lithographic methods for forming such layers. The layers include a plurality of structures, and a residual layer having a residual layer thickness (RLT) that extends from the surface of the substrate to a base of the structures, where the RLT varies across the surface of the substrate according to a predefined pattern.

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.

Abstract: Fabricating a high refractive index photonic device includes disposing a polymerizable composition on a first surface of a first substrate and contacting the polymerizable composition with a first surface of a second substrate, thereby spreading the polymerizable composition on the first surface of the first substrate. The polymerizable composition is cured to yield a polymeric structure having a first surface in contact with the first surface of the first substrate, a second surface opposite the first surface of the polymeric structure and in contact with the first surface of the second substrate, and a selected residual layer thickness between the first surface of the polymeric structure and the second surface of the polymeric structure in the range of 10 ?m to 1 cm. The polymeric structure is separated from the first substrate and the second substrate to yield a monolithic photonic device having a refractive index of at least 1.6.

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: A method of fabricating a shadow mask includes depositing a chrome etch mask layer on a substrate. The substrate includes a silicon handle wafer, a buried oxide layer, a single crystal silicon layer, and a backside oxide layer. The method also includes forming a patterning layer including a pattern on the chrome etch mask layer, etching the chrome etch mask layer using the patterning layer to transfer the pattern in the patterning layer into the chrome etch mask layer, and etching the pattern of the chrome etch mask layer into the single crystal silicon layer. The method further includes patterning the backside oxide layer, etching the silicon handle wafer using the patterned backside oxide layer, removing the buried oxide layer, and removing remaining portions of the patterned chrome etch mask layer and the patterning layer.