# US 2019/0170932 A1 · Edge sealant confinement and halo reduction for optical devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170932 A1 - Document ID: US20190170932A1 - Status: Published application - Kind: A1 - Application number: 16/270,243 - Filed: 2019-02-07 - Published: 2019-06-06 - Earliest claimed: 2016-08-26 - Assignees: Molecular Imprints, Inc. - Applicants: Molecular Imprints, Inc. - Inventors: Michael Nevin Miller; Frank Y. Xu; Vikramjit Singh; Eric C. Browy; Jason Schaefer; Robert D. TeKolste; Victor Kai Liu; Samarth Bhargava; Jeffrey Dean Schmulen; Brian T. Schowengerdt - Web page: https://patentgrep.com/patent/US20190170932A1 ## CPC - G02B 6/02142: {based on illuminating or irradiating an amplitude mask, i.e. a mask having a repetitive intensity modulating pattern} - G02B 25/001: {Eyepieces} - G02B 5/003: {Light absorbing elements} - G02B 6/02309: {Structures extending perpendicularly or at a large angle to the longitudinal axis of the fibre, e.g. photonic band gap along fibre axis} - G02B 6/12016: {characterised by the input or output waveguides, e.g. tapered waveguide ends, coupled together pairs of output waveguides} - G02B 6/3534: {the optical element being diffractive, i.e. a grating} - G02B 27/01: Head-up displays - G02F 1/3515: {All-optical modulation, gating, switching, e.g. control of a light beam by another light beam (G02F1/353, G02F1/37, G02F1/39 take precedence)} - G02B 27/0018: {with means for preventing ghost images (anti-reflection coatings G02B1/11)} - G02F 2201/307: Reflective grating, i.e. Bragg grating - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## 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. ## Claims ### Claim 1 An optical structure comprising: a substrate including: a first grating pattern forming an optically functional region of the substrate; and a second grating pattern on the substrate and proximal to an edge of the substrate, the second grating pattern arranged to control capillary flow of a material from the edge of the substrate into the second grating pattern and inhibit the capillary flow of the material into the optically functional region of the substrate. ### Claim 2 (depends on 1) The optical structure of claim 1, wherein: the first grating pattern is on a first surface of the substrate; and the second grating pattern is on a second surface of the substrate. ### Claim 3 (depends on 1) The optical structure of claim 1, wherein the first grating pattern and the second grating pattern are on a first surface of the substrate. ### Claim 4 (depends on 1) The optical structure of claim 1, wherein the substrate further includes a third grating forming a second optically functional region of the substrate. ### Claim 5 (depends on 1) The optical structure of claim 1, wherein the optically functional region of the substrate includes one or more of an orthogonal pupil expander (OPE) region and an exit pupil expander (EPE) region. ### Claim 6 (depends on 1) The optical structure of claim 1, wherein the second grating pattern includes one or more features that are arranged to be substantially parallel to the edge of the substrate. ### Claim 7 (depends on 1) The optical structure of claim 1, wherein the second grating pattern includes one or more of a V-shaped grating pattern, an S-shaped grating pattern, and a rectangular grating pattern. ### Claim 8 (depends on 1) The optical structure of claim 1, wherein: the second grating pattern includes one or more first features that are arranged to be substantially perpendicular to the edge of the substrate; the second grating pattern includes one or more second features that are arranged to be substantially parallel to the edge of the substrate and to inhibit the capillary flow of the material beyond the second grating pattern; and the one or more second features differ, at least in part, from the one or more first features in at least one of depth, height, and width. ### Claim 9 (depends on 1) The optical structure of claim 1, wherein the material has a refractive index that is lower than that of the substrate. ### Claim 10 (depends on 1) The optical structure of claim 1, wherein the material, as applied, has a gradient of refractive index that varies according to a distance from the edge of the substrate. ### Claim 11 (depends on 1) The optical structure of claim 1, wherein the second grating pattern includes one or more features that have a cross-sectional shape of at least one polygon. ### Claim 12 (depends on 11) The optical structure of claim 11, wherein the at least one polygon includes one or more of a triangle, a square, and a rectangle. ### Claim 13 (depends on 1) The optical structure of claim 1, wherein: the substrate is a waveguide configured to receive and propagate light; and the material is a light variable absorptive edge material configured to receive and absorb light from the waveguide. ### Claim 14 (depends on 1) The optical structure of claim 1, wherein the material and the substrate have a substantially same index of refraction. ### Claim 15 (depends on 1) The optical structure of claim 1, wherein the material comprises a doping agent and an adhesive. ### Claim 16 (depends on 15) The optical structure of claim 15, wherein the doping agent is distributed at a gradient that varies with distance from an edge of the substrate. ### Claim 17 (depends on 15) The optical structure of claim 15, wherein the doping agent comprises carbon black nanoparticles. ### Claim 18 (depends on 17) The optical structure of claim 17, wherein the carbon black nanoparticles have a diameter in a range of 50-70 nm. ### Claim 19 (depends on 1) The optical structure of claim 1, wherein the material comprises at least one of a doping agent and an adhesive that is included in at least one layer of adhesive tape. ### Claim 20 (depends on 19) The optical structure of claim 19, wherein the adhesive tape and the substrate have a substantially same index of refraction. ### Claim 21 (depends on 1) The optical structure of claim 1, wherein: the substrate is one of a plurality of layers of substrate included in the optical structure; each of the plurality of layers includes the second grating pattern proximal to a respective edge of the layer; and the material is an edge adhesive that is applied along at least a portion of a perimeter of the optical structure to secure the plurality of layers of substrate. ### Claim 22 (depends on 21) The optical structure of claim 21, wherein each of the plurality of layers of substrate further includes the first grating pattern on a respective optically functional region of the respective layer. ### Claim 23 (depends on 22) The optical structure of claim 22, wherein: the first grating pattern is nano-scale and arranged to provide a waveguide for light propagation in the optically functional region; and the second grating pattern is micro-scale or nano-scale.