Abstract: A waveguide includes a set of grating structures forming a component on the surface of the waveguide. The set of grating structures is configured to direct light received at the component based on a parameter of one or more grating structures of the set of grating structures. Further, the waveguide includes a first transition area disposed adjacent to a first side of the component wherein the parameter is modulated across the grating structures of the first transition area. Additionally, the waveguide includes a second transition area disposed adjacent to a second, opposite side of the component wherein the parameter is also modulated across the grating structures of the second transition area.

Abstract: Systems and methods for managing multi-objective alignments in imprinting (e.g., single-sided or double-sided) are provided. An example system includes rollers for moving a template roll, a stage for holding a substrate, a dispenser for dispensing resist on the substrate, a light source for curing the resist to form an imprint on the substrate when a template of the template roll is pressed into the resist on the substrate, a first inspection system for registering a fiducial mark of the template to determine a template offset, a second inspection system for registering the imprint on the substrate to determine a wafer registration offset between a target location and an actual location of the imprint, and a controller for controlling to move the substrate with the resist below the template based on the template offset, and determine an overlay bias of the imprint on the substrate based on the wafer registration offset.

Abstract: Display devices include waveguides with in-coupling optical elements that mitigate re-bounce of in-coupled light to improve in-coupling efficiency and/or uniformity. A waveguide receives light from a light source and includes an in-coupling optical element that in-couples the received light to propagate by total internal reflection within the waveguide. The in-coupled 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 reducing the amount of in-coupled light propagating through the waveguide.

Abstract: A fabrication process uses casting to form portions of a waveguide having ultra-flat surfaces. A casting resin is coated between a prism mold and a top flat mold via inkjet, slot die, spray coating, etc. The top flat mold is lowered to conform with the casting resin and the casting resin is then cured to form a bottom prism array. After curing, the bottom prism array is demolded from the prism mold and the top flat mold is used as a carrier wafer to support the bottom prism array. The bottom prism array is selectively coated with a reflective coating and a second casting process is performed by coating the bottom prism array with casting resin to form a reflective waveguide.

Abstract: Systems and methods for managing multi-objective alignments in imprinting (e.g., single-sided or double-sided) are provided. An example system includes rollers for moving a template roll, a stage for holding a substrate, a dispenser for dispensing resist on the substrate, a light source for curing the resist to form an imprint on the substrate when a template of the template roll is pressed into the resist on the substrate, a first inspection system for registering a fiducial mark of the template to determine a template offset, a second inspection system for registering the imprint on the substrate to determine a wafer registration offset between a target location and an actual location of the imprint, and a controller for controlling to move the substrate with the resist below the template based on the template offset, and determine an overlay bias of the imprint on the substrate based on the wafer registration offset.

Abstract: Diffraction gratings provide optical elements, e.g., in a head-mountable display system, that can affect light, for example by incoupling light into a waveguide, outcoupling light out of a waveguide, and/or multiplying light propagating in a waveguide. The diffraction gratings may be configured to have reduced polarization sensitivity such that light of different polarization states, or polarized and unpolarized light, is incoupled, outcoupled, multiplied, or otherwise affected with a similar level of efficiency. The reduced polarization sensitivity may be achieved through provision of a transmissive layer and a metallic layer on one or more gratings. A diffraction grating may comprise a blazed grating or other suitable configuration.

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: A method of nanoimprinting a waveguide includes forming a working stamp having at least one waveguide feature pattern and at least one process control feature pattern. The working stamp is pressed into a waveguide workpiece thereby forming waveguide features in one or more functional waveguide zones of the waveguide workpiece and one or more sets of process control features in one or more regions outside of the one or more functional waveguide zones. The working stamp is detached from the waveguide workpiece.

Abstract: Systems, apparatus, and methods for double-sided imprinting are provided. An example system includes first rollers for moving a first web including a first template having a first imprinting feature, second rollers for moving a second web including a second template having a second imprinting feature, dispensers for dispensing resist, a locating system for locating reference marks on the first and second webs for aligning the first and second templates, a light source for curing the resist, such that a cured first resist has a first imprinted feature corresponding to the first imprinting feature on one side of the substrate and a cured second resist has a second imprinted feature corresponding to the second imprinting feature on the other side of the substrate, and a moving system for feeding in the substrate between the first and second templates and unloading the double-imprinted substrate from the first and second webs.

Abstract: A method of optical device metrology is provided. The method includes introducing a first type of light into a first optical device during a first time period, the first optical device including an optical substrate and an optical film disposed on the optical substrate, the first optical device further including a first surface, a second surface, and one or more sides connecting the first surface with the second surface; and measuring, during the first time period, a quantity of the first type of light transmitted from a plurality of locations on the first surface or the second surface during the first time period, wherein the measuring is performed by a detector coupled to one or more fiber heads positioned to collect the light transmitted from the plurality of locations.

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: 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: Techniques for fabricating a polymer reflective waveguide mold with high structural quality control (flatness, alignment, dimensions) and high precision and groove parallelism for high optical quality include using optical lithography and wet etch process. For example, a method of fabricating a reflective waveguide mold includes depositing a hard mask layer on a crystalline substrate, lithographically patterning the hard mask layer, and anisotropically removing the crystalline substrate to form a prism array waveguide mold.

Abstract: A method of imprinting a pattern on a substrate is provided. The method includes forming a first pattern on a plurality of masters using a method other than imprinting, the first pattern including a plurality of patterned features of varying sizes; measuring the patterned features at a plurality of locations on each of the masters; selecting a first master of the plurality of masters based on the measurements of the patterned features on each of the masters; using the first master to form a second pattern on an imprint template; and imprinting the first pattern on a first device with the imprint template.

Abstract: The present disclosure generally relates to a method and apparatus for forming a substrate having a graduated refractive index. A method of forming a waveguide structure includes expelling plasma from an applicator having a head toward a plurality of grating structures formed on a substrate. The plasma is formed in the head at atmospheric pressure. The method further includes changing a depth of the plurality of grating structures with the plasma by removing grating material from the plurality of grating structures.

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: Systems, methods, devices and storage media for graph data processing are provided. In one aspect, a graph data processing system includes a memory and a plurality of processing units, and each processing unit is provided with a decision module. Each processing unit is configured to determine set operations required for extracting one or more subgraphs matching a specified graph pattern from target graph data according to a preset graph pattern matching algorithm. Then, for each set operation, the decision module is configured to determine a cost value corresponding to a performance of the processing unit occupied to execute the set operation in accordance with different execution policies, and further select a target execution policy with a smallest cost value to execute the set operation.

Abstract: Systems, apparatus, and methods for double-sided imprinting are provided. An example system includes first rollers for moving a first web including a first template having a first imprinting feature, second rollers for moving a second web including a second template having a second imprinting feature, dispensers for dispensing resist, a locating system for locating reference marks on the first and second webs for aligning the first and second templates, a light source for curing the resist, such that a cured first resist has a first imprinted feature corresponding to the first imprinting feature on one side of the substrate and a cured second resist has a second imprinted feature corresponding to the second imprinting feature on the other side of the substrate, and a moving system for feeding in the substrate between the first and second templates and unloading the double-imprinted substrate from the first and second webs.

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.