Facebook Technologies, LLC

Meta Platforms Technologies, LLC

Facebook Technologigegs, LLC

Austin Lane

Matthew E Colburn

Giuseppe Calafiore

Nihar Ranjan Mohanty

Andrew John Ouderkirk

Katherine Marie Smyth

Tanya Malhotra

Christopher Yuan Ting Liao

Jack Lindsay

Matthieu Charles Raoul Leibovici

Thomas John Farrell Wallin

Tingling Rao

Yigit Menguc

Wanli Chi

Ankit Vora

Kenneth Alexander Diest

Yigit Mengue

Kavous Jorabchi

Hee Yoon Lee

Yang Yang

Lafe Purvis

Elliott Franke

Thomas Wallin

Janee Ashley McNeil

Marvin Dion Alim

Wai Sze Tiffany Lam

Maxwell Parsons

Renate Eva Klementine Landig

Ningfeng Huang

Alexander Koshelev

Richard Farrell

Ken Diest

The present disclosure relates to systems and methods of making polymeric optical layers for optical layering applications. In an aspect, a waveguide device for a head mounted display is provided. The waveguide device may include a waveguide die having a first refractive index range and a polymeric optical layer. The polymeric optical layer may include a second refractive index range that is different from the first refractive index range and a thiol-containing polymer. For example, the thiol-containing polymer may include thiourethane. In some embodiments, the thiol-containing polymer may be formed from a monomer mixture including a thiol-containing compound and an isocyanate. For example, the thiol-containing compound may include 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol (MDTODT) and/or the isocyanate may include m-xylylene diisocyanate (XDI). In some embodiments, the monomer mixture may include a second thiol-containing compound, such as, for example, 1,3-benzene dithiol (1,3-BDT).

Systems and methods of making polymeric optical layers for optical layering

A method for making an optical grating having a non-uniform refractive index profile along a direction substantially perpendicular to a plane defined by the optical grating includes placing a layer of photopolymerization material having a first surface and a second surface that is opposite to the first surface between a first material transfer layer and a second material transfer layer so that the first surface of the layer of photopolymerization material is in contact with the first material transfer layer and the second surface of the layer of photopolymerization material is in contact with the second material transfer layer to allow material transfer between the layer of photopolymerization material and the first and second material transfer layers by diffusion.

Chemical diffusion treated volume holograms and methods for making the same

An optical device with a variable index of refraction is formed by exposing a film to an energy gradient. The optical device has angular selectivity. The optical device can be used as an output coupler for a waveguide used in a virtual-reality and/or augmented-reality apparatus.

Diffraction grating with a variable refractive index formed using an energy gradient

The disclosure provides recording materials including aromatic substituted alkane-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, including Formula I. When used in Bragg gratings applications, the monomers and polymers disclosed lead to materials with higher refractive index, low birefringence, and high transparency. The disclosed derivatized monomers and polymers 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.

Aromatic substituted alkane-core monomers and polymers thereof for volume Bragg gratings

Techniques disclosed herein relate to holographic optical materials and elements. An example of a holographic recording material includes matrix monomers characterized by a first refractive index and configured to polymerize to form a polymer matrix, writing monomers dispersed in the matrix monomers and characterized by a second refractive index different from the first refractive index, and a photocatalyst for controlled radical polymerization of the writing monomers. The writing monomers are configured to polymerize upon exposed to recording light. The photocatalyst is dispersed in the matrix monomers. The photocatalyst includes, for example, a transition metal photocatalyst or a metal-free organic photocatalyst, such as a photocatalyst for atom transfer radical polymerization or a transition metal photocatalyst for addition fragmentation chain transfer polymerization.

Light-activated controlled radical polymerization

The disclosure provides recording materials include fluorene derivatized monomers and polymers for use in volume Bragg gratings, including, but not limited to, volume Bragg gratings for holography applications. Several fluorene structures are disclosed: simply substituted fluorenes, cardo-fluorenes, and spiro-fluorenes. Fluorene derivatized polymers in Bragg gratings applications lead to materials with higher refractive index, low birefringence, and high transparency. Fluorene derivatized monomers/polymers 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.

Fluorene derivatized monomers and polymers for volume Bragg gratings

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.

Gray-tone lithography for precise control of grating etch depth

Initiator/mediator chemistry for latent imaging polymers for volume Bragg gratings is provided. Light mediated chemistry including the use of nitroxides allows a first step imaging to occur, where a light induced pattern is recorded in the material, without the grating being apparent. A second bleaching/developing step completes the curing process and reveals the grating.

Latent imaging for volume Bragg gratings

A grating coupler may be fabricated by exposing a photopolymer layer to grating forming light for forming periodic refractive index variations in the photopolymer layer. The photopolymer layer may be exposed to apodization light for reducing an amplitude of the periodic refractive index variations in a spatially-selective manner. The apodization may also be achieved or facilitated by subjecting outer surface(s) of the photopolymer layer to a chemically reactive agent that causes the refractive index contrast to be reduced near the surface(s) of application. The apodized refractive index profile of the gratings facilitates the reduction of optical crosstalk between different gratings of the grating coupler.

Apodization of refractive index profile in volume gratings

A method is described for utilizing NIL materials with switchable mechanical properties. The method comprises applying an imprint mask to a nano-imprint lithography (NIL) material layer. The NIL material layer is comprised of a NIL material with a modulus level below a flexibility threshold. The NIL material layer has an internal property, that when changed, causes a change in the modulus level of the NIL material. The method further comprises detaching the imprinted NIL material layer from the imprint mask, with the low modulus level of the NIL material causing a shape of the imprinted NIL material layer to remain unchanged after detachment. A modulus level of the NIL material is increased by changing an internal property of the NIL material, with the modulus level increased beyond a strength threshold to create a first imprint layer that has a structure that remains unaffected by a subsequent process.

Nanoimprint lithography material with switchable mechanical properties

Techniques disclosed herein relate to modifying refractive index modulation in a holographic optical element, such as a holographic grating. According to certain embodiments, a holographic optical element or apodized grating includes a polymer layer comprising a first region characterized by a first refractive index and a second region characterized by a second refractive index. The holographic optical element or apodized grating includes a plurality of nanoparticles dispersed in the polymer layer. The nanoparticles have a higher concentration in either the first region or the second region. In some embodiments, the nanoparticles may be configured to increase the refractive index modulation. In some embodiments, the nanoparticles may be configured to apodize the grating by decreasing the refractive index modulation proximate to sides of the grating. The refractive index may be modulated by applying a monomer reservoir buffer layer to the polymer layer, either before or after hologram fabrication.

Refractive index modulation modification in a holographic grating

A method of forming a nanovoided composite polymer includes forming a resin-containing layer over a substrate, the resin-containing layer including a polymer-forming phase and a sacrificial phase, curing the polymer-forming phase to form a polymer matrix containing the sacrificial phase, and removing the sacrificial phase selectively with respect to the polymer matrix to form a nanovoided composite polymer including the polymer matrix and nanovoids dispersed throughout the polymer matrix. The nanovoids may be randomly or regularly dispersed throughout the matrix. Various other methods, systems, apparatuses, and materials are also disclosed.

Methods for forming ordered and disordered nanovoided composite polymers

Embodiments relate to a method of fabricating a nano-sized structure in a resin element by nanoimprint lithography (NIL). The method reduces adhesive failure during NIL demolding by forming a layer of polymerization inhibiting compound at the interface of the resin element and template. The resin element is made with a mixture of a polymerization inhibiting compound (e.g., a perfluorinated compound) and a resin (e.g., a fluorine resin). The method includes aging the resin element to promote migration of the polymerization inhibiting compound to an interface of the resin element with air. The method also includes pressing a surface of a template having a nano-sized pattern onto the surface of the resin element exposed to the air to form the nano-sized structure in the resin element. The method further includes curing the resin element after the nano-sized structure is formed and then removing the template from the resin element.

Reducing adhesive failure during nanoimprint lithography demolding

Embodiments relate to a method of fabricating a nano-sized structure in a resin element by nanoimprint lithography (NIL). The method reduces adhesive failure during NIL demolding by inhibiting polymerization at the interface between the resin element and the template. The method includes depositing a layer of polymerization inhibiting compound onto a surface of the template. The layer of polymerization inhibiting compound has a thickness no more than 10 nanometers. A surface of the template has a nano-sized pattern that mirrors that nano-sized structure. The method further includes pressing the template onto the resin element (or the resin element onto the template) to form the nano-sized structure in the resin element. The process also includes curing the resin element after forming the nano-sized structure and removing the template from the resin element after curing the resin element. The polymerization inhibiting compound prevents adhesive failure during the removing.

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.

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Redmond, WA, United States of America

Austin Lane