Abstract: The disclosure provides recording materials including propane derivatized monomers and polymers for use in volume Bragg gratings, including, but not limited to, volume Bragg gratings for holography applications. Several structures are disclosed for propane derivatized monomers and polymers for use in Bragg gratings applications, leading to materials with higher refractive index, low birefringence, and high transparency. The disclosed propane derivatized monomers and polymers thereof can be used in any volume Bragg gratings materials, including two-stage polymer materials where a matrix is cured in a first step, and then the volume Bragg grating is written by way of a second curing step of a monomer.

Abstract: The disclosure provides recording materials including mono- or poly-phenyl-core derivatized monomers and polymers for use in volume Bragg gratings, including, but not limited to, volume Bragg gratings for holography applications. Several structures are disclosed for mono- or poly-phenyl-core derivatized monomers and polymers for use in Bragg gratings applications, leading to materials with higher refractive index, low birefringence, and high transparency. The disclosed mono- or poly-phenyl-core derivatized monomers and polymers thereof can be used in any volume Bragg gratings materials, including two-stage polymer materials where a matrix is cured in a first step, and then the volume Bragg grating is written by way of a second curing step of a monomer.

Abstract: An electronic display assembly includes a display element and a corrective element coupled to the display element. The display element has a first plurality of sub-pixels of a first type and a second plurality of sub-pixels of a second type. Two adjacent sub-pixels of the first plurality of sub-pixel are separated by a sub-pixel distance. The corrective element has a plurality of features configured to diffuse light emitted by the first plurality of sub-pixels such that an apparent distance between the two adjacent sub-pixels of the first type, viewed at a viewing distance away from the electronic display assembly, is less than the sub-pixel distance.

Abstract: A method is described for modifying the mechanical properties of NIL materials. The method includes applying an imprint mask to a nano-imprint lithography (NIL) material layer to create an imprinted NIL material layer, with the NIL material layer comprised of a NIL material. The method further includes detaching the imprinted NIL material layer from the imprint mask, with the modulus level of the NIL material below a flexibility threshold to cause a shape of the imprinted NIL material layer to remain unchanged after detachment. The modulus level of the NIL material of the imprinted NIL material layer is increased beyond a strength threshold to create a first imprint layer, with the imprint layer having a structure that remains unaffected by a subsequent process to form a second imprint layer matching a master mold pattern.

Abstract: An electronic display assembly includes a display element and a corrective element coupled to the display element. The display element has a first plurality of sub-pixels of a first type and a second plurality of sub-pixels of a second type. Two adjacent sub-pixels of the first plurality of sub-pixel are separated by a sub-pixel distance. The corrective element has a plurality of features configured to diffuse light emitted by the first plurality of sub-pixels such that an apparent distance between the two adjacent sub-pixels of the first type, viewed at a viewing distance away from the electronic display assembly, is less than the sub-pixel distance.

Abstract: Gray-tone lithography techniques for controlling the thickness profile of an overcoat layer on a surface-relief grating that has a non-uniform grating parameter (e.g., depth, duty cycle, or period), compensating for the non-uniform etch rate in a large area, defining etch/block regions, and/or controlling the thickness of the grating layer.

Abstract: A method of fabricating gratings with variable grating depths including depositing a first grating material layer with a uniform thickness profile on a substrate, forming an etch mask layer having a variable thickness profile on the first grating material layer, etching the etch mask layer and the first grating material layer to change the uniform thickness profile of the first grating material layer to a non-uniform thickness profile, forming a patterned hard mask on the first grating material layer, and etching, using the patterned hard mask, the first grating material layer to form a grating with a variable depth in the first grating material layer.

Abstract: Techniques for fabricating a slanted structure are disclosed. In one embodiment, a method of fabricating a slanted surface-relief structure in a material layer includes forming a thin hard mask on top of an intermediate mask layer, etching the intermediate mask layer at a slant angle using the thin hard mask to form a slanted intermediate mask, and etching the material layer at the slant angle using the slanted intermediate mask to form the slanted surface-relief structure in the material layer. The intermediate mask layer is characterized by an etch rate greater than an etch rate of the material layer.

Abstract: A manufacturing system for creating waveguides that include optical gratings having high coupling efficiencies is described herein. The waveguides are used to guide image light from a source assembly to an eye of a user. The optical gratings are used to couple light into an optical waveguide element and/or decouple light from the optical waveguide element. The manufacturing system creates optical gratings by patterning and adjusts refractive indexes of the optical gratings by infusion and post-processing. A refractive index of an optical grating can be uniform or non-uniform. In-coupling efficiencies of light into a waveguide via the optical gratings and/or out-coupling efficiencies of light out of a waveguide via the optical gratings can be increased. The manufacturing system includes a patterning system, an infusion system, and a post-processing system.

Abstract: A method is described for modifying the mechanical properties of NIL materials. The method includes applying an imprint mask to a nano-imprint lithography (NIL) material layer to create an imprinted NIL material layer, with the NIL material layer comprised of a NIL material. The method further includes detaching the imprinted NIL material layer from the imprint mask, with the modulus level of the NIL material below a flexibility threshold to cause a shape of the imprinted NIL material layer to remain unchanged after detachment. The modulus level of the NIL material of the imprinted NIL material layer is increased beyond a strength threshold to create a first imprint layer, with the imprint layer having a structure that remains unaffected by a subsequent process to form a second imprint layer matching a master mold pattern.

Abstract: A manufacturing system for fabricating self-aligned grating elements with a variable refractive index includes a patterning system, a deposition system, and an etching system. The manufacturing system performs a lithographic patterning of one or more photoresists to create a stack over a substrate. The manufacturing system performs a conformal deposition of a protective coating on the stack. The manufacturing system performs a deposition of a first photoresist of a first refractive index on the protective coating. The manufacturing system performs a removal of the first photoresist to achieve a threshold value of first thickness. The manufacturing system performs a deposition of a second photoresist of a second refractive index on the first photoresist. The second refractive index is greater than the first refractive index. The manufacturing system performs a removal of the second photoresist to achieve a threshold value of second thickness to form a portion of an optical grating.

Abstract: A method is described for creating a modified mask with low surface energies for a nano-imprint lithography (NIL) imprinting process. The method includes applying a master mold to an imprint mask material to create an imprint mask. The method further includes modifying the imprint mask by applying a treatment to the imprint mask to cause a surface energy level of the imprint mask to fall below a sticking threshold. The modified imprint mask is applied to a nano-imprint lithography (NIL) material to create an imprinted NIL material layer. The surface energy level of the imprint mask causes a shape of the imprinted NIL material layer to be remain unchanged when the imprinted NIL material layer is detached from the modified imprint mask.

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 etch heights relative to the substrate. The manufacturing system performs a lithographic patterning of a photoresist deposited over the created profile in the etch-compatible film to obtain the plurality of etch heights and one or more duty cycles corresponding to the etch-compatible film deposited over the substrate.

Abstract: A method is described for creating a modified mask with low surface energies for a nano-imprint lithography (NIL) imprinting process. The method includes applying a master mold to an imprint mask material to create an imprint mask. The method further includes modifying the imprint mask by applying a treatment to the imprint mask to cause a surface energy level of the imprint mask to fall below a sticking threshold. The modified imprint mask is applied to a nano-imprint lithography (NIL) material to create an imprinted NIL material layer. The surface energy level of the imprint mask causes a shape of the imprinted NIL material layer to be remain unchanged when the imprinted NIL material layer is detached from the modified imprint mask.

Abstract: Techniques for fabricating a slanted structure are disclosed. In one embodiment, a method of fabricating a slanted surface-relief structure in a material layer includes forming a thin hard mask on top of an intermediate mask layer, etching the intermediate mask layer at a slant angle using the thin hard mask to form a slanted intermediate mask, and etching the material layer at the slant angle using the slanted intermediate mask to form the slanted surface-relief structure in the material layer. The intermediate mask layer is characterized by an etch rate greater than an etch rate of the material layer.

Abstract: Techniques for fabricating a slanted structure are disclosed. In one embodiment, a method for fabricating a slanted structure on a material layer includes forming a mask layer on the material layer, and implanting ions into a plurality of regions of the material layer at a slant angle greater than zero using an ion beam and the mask layer. The slant angle is measured with respect to a surface normal of the material layer. Implanting the ions into the plurality of regions of the material layer changes a refractive index or an etch rate of the plurality of regions of the material layer. In some embodiments, the method further includes wet-etching the material layer using an etchant to remove materials in the plurality of regions of the material layer. In some embodiments, the method includes either simultaneous or post-implantation etching of modified material through a dry etching process using reactive etchants in feed gas.

Abstract: A manufacturing system for fabricating self-aligned grating elements with a variable refractive index includes a patterning system, a deposition system, and an etching system. The manufacturing system performs a lithographic patterning of one or more photoresists to create a stack over a substrate. The manufacturing system performs a conformal deposition of a protective coating on the stack. The manufacturing system performs a deposition of a first photoresist of a first refractive index on the protective coating. The manufacturing system performs a removal of the first photoresist to achieve a threshold value of first thickness. The manufacturing system performs a deposition of a second photoresist of a second refractive index on the first photoresist. The second refractive index is greater than the first refractive index. The manufacturing system performs a removal of the second photoresist to achieve a threshold value of second thickness to form a portion of an optical grating.

Abstract: A method of forming a structure for etch masking that includes forming first dielectric spacers on sidewalls of a plurality of mandrel structures and forming non-mandrel structures in space between adjacent first dielectric spacers. Second dielectric spacers are formed on sidewalls of an etch mask having a window that exposes a connecting portion of a centralized first dielectric spacer. The connecting portion of the centralized first dielectric spacer is removed. The mandrel structures and non-mandrel structures are removed selectively to the first dielectric spacers to provide an etch mask. The connecting portion removed from the centralized first dielectric spacer provides an opening connecting a first trench corresponding to the mandrel structures and a second trench corresponding to the non-mandrel structures.

Abstract: A manufacturing system for fabricating self-aligned grating elements with a variable refractive index includes a patterning system, a deposition system, and an etching system. The manufacturing system performs a lithographic patterning of one or more photoresists to create a stack over a substrate. The manufacturing system performs a conformal deposition of a protective coating on the stack. The manufacturing system performs a deposition of a first photoresist of a first refractive index on the protective coating. The manufacturing system performs a removal of the first photoresist to achieve a threshold value of first thickness. The manufacturing system performs a deposition of a second photoresist of a second refractive index on the first photoresist. The second refractive index is greater than the first refractive index. The manufacturing system performs a removal of the second photoresist to achieve a threshold value of second thickness to form a portion of an optical grating.

Abstract: A manufacturing system performs a lithographic patterning of a resist formed on a substrate to create a first optical grating including a plurality of structures at a first slant angle relative to the substrate. The manufacturing system performs a tunable shrinkage of the plurality of structures to adjust the first slant angle to a target slant angle different from the first slant angle. In some embodiments, the manufacturing system performs a post-processing of the plurality of structures to create a second optical grating from the first optical grating. The post-processing may adjust at least one of: a refractive index, a height, and a volume of the first optical grating.