# US 12,601,918 B2 · Optical structure and optical device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,601,918 B2 - Document ID: US12601918B2 - Status: Granted - Kind: B2 - Application number: 18/391,003 - Filed: 2023-12-20 - Published: 2024-04-11 - Granted: 2026-04-14 - Earliest claimed: 2021-07-30 - Assignees: Guangdong Oppo Mobile Telecommunications Corp., Ltd. - Applicants: Guangdong Oppo Mobile Telecommunications Corp., Ltd. - Inventors: Chuhao Jiang - Web page: https://patentgrep.com/patent/US12601918B2 ## CPC - G02B 27/0172: {characterised by optical features} - G02B 6/124: Geodesic lenses or integrated gratings - G02B 27/0081: {with means for altering, e.g. enlarging, the entrance or exit pupil} - G02B 27/01: Head-up displays - G02B 27/44: Grating systems; Zone plate systems (G02B27/46 takes precedence) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract The present application discloses an optical structure. The optical structure includes a waveguide, and a first coupling-out grating, a second coupling-out grating, and a third coupling-out grating provided on the waveguide. The third coupling-out grating is located between the first coupling-out grating and the second coupling-out grating; the first coupling-out grating is a two-dimensional grating having a plurality of first grids, and the first grid is in an asymmetric shape, such that light efficiency of the first coupling-out grating propagating along a first direction is higher than light efficiency of the first coupling-out grating propagating along a second direction. ## Claims ### Claim 1 An optical structure, comprising: a waveguide; a first coupling-out grating, arranged on the waveguide; a second coupling-out grating, arranged on the waveguide; and a third coupling-out grating, arranged on the waveguide, wherein the third coupling-out grating is located between the first coupling-out grating and the second coupling-out grating; wherein the first coupling-out grating is a two-dimensional grating with a plurality of first grids, the first grid has an asymmetric shape to allow light propagation efficiency of the first coupling-out grating along a first direction is higher than light propagation efficiency of the first coupling-out grating along a second direction; and wherein the first direction is a direction in which the first coupling-out grating faces the second coupling-out grating, and the first direction is opposite to the second direction. ### Claim 2 (depends on 1) The optical structure according to claim 1, further comprising a coupling-in grating, wherein the coupling-in grating is arranged at a same side of the first coupling-out grating, the second coupling-out grating and the third coupling-out grating, and the coupling-in grating and the third coupling-out grating are arranged side by side; wherein the first grid comprises three vertices and has a first vertex-connecting line, a second vertex-connecting line and a third vertex-connecting line, the first vertex-connecting line is close to the third coupling-out grating, the second vertex-connecting line is away from the third coupling-out grating, a length of the first vertex-connecting line is greater than a length of the second vertex-connecting line, an angle between the first vertex-connecting line and the third coupling-out grating along a five direction is an acute angle, and an angle between the second vertex-connecting line and the third coupling-out grating in the fifth direction is an obtuse angle; and wherein the fifth direction is a direction in which the third coupling-out grating faces the coupling-in grating. ### Claim 3 (depends on 1) The optical structure according to claim 1, further comprising a coupling-in grating, wherein the coupling-in grating is arranged at a same side of the first coupling-out grating, the second coupling-out grating and the third coupling-out grating, and the coupling-in grating and the third coupling-out grating are arranged side by side; wherein the first grid comprises at least five vertices, and the vertices of the first grid comprise two vertices close to the third coupling-out grating and three vertices away from the third coupling-out grating, the two vertices close to the third coupling-out grating and the three vertices away from the third coupling-out grating are capable of forming a third diagonal line and a fourth diagonal line, a length of the third diagonal line is greater than a length of the fourth diagonal line, an angle between the third diagonal line and the third coupling-out grating along a fourth direction is an acute angle, and an angle between the fourth diagonal line and the third coupling-out grating along the fourth direction is an obtuse angle; wherein the fourth direction is a direction in which the third coupling-out grating faces the coupling-in grating. ### Claim 4 (depends on 1) The optical structure according to claim 1, further comprising a coupling-in grating, wherein the coupling-in grating is arranged at a same side of the first coupling-out grating, the second coupling-out grating and the third coupling-out grating, and the coupling-in grating and the third coupling-out grating are arranged side by side; wherein the first grid comprises four vertices capable of forming a first diagonal line and a second diagonal line, a length of the first diagonal line is greater than a length of the second diagonal line, an angle between the first diagonal line and the third coupling-out grating along a third direction is an acute angle, and an angle between the second diagonal line and the third coupling-out grating along the third direction is an obtuse angle; and wherein the third direction is a direction in which the third coupling-out grating faces the coupling-in grating. ### Claim 5 (depends on 4) The optical structure according to claim 4, wherein the first coupling-out grating has a plurality of grid groups, each grid group comprises a plurality of the first grids, each first grid in each grid group intersects with its adjacent first grid, and each grid group is spaced apart from each other. ### Claim 6 (depends on 5) The optical structure according to claim 5, wherein each grid group is parallel to each other, or each first grid in each grid group is arranged along a sixth direction, the sixth direction is a direction in which a seventh direction rotates 30 degrees clockwise, and the seventh direction is a direction in which the third coupling-out grating faces the coupling-in grating. ### Claim 7 (depends on 4) The optical structure according to claim 4, wherein the third coupling-out grating is a two-dimensional grating with a plurality of third grids, and the third grid has a symmetrical shape; the first coupling-out grating, the second coupling-out grating and the third coupling-out grating are all two-dimensional gratings, grating periods of the first coupling-out grating, the second coupling-out grating and the third coupling-out grating are equal, and refractive index of either of the first coupling-out grating, the second coupling-out grating and the third coupling-out grating to the waveguide is 1.5-3; and a grating period of the coupling-in grating is one-half of a grating period of the first coupling-out grating along a direction perpendicular to the first direction. ### Claim 8 (depends on 1) The optical structure according to claim 1, wherein the third coupling-out grating comprises at least two sub-coupling-out gratings, a junction of two adjacent sub-coupling-out gratings is located within an eyebox of the optical structure, and diffraction efficiency of the sub-coupling-out grating away from the coupling-in grating is greater than diffraction efficiency of the sub-coupling-out grating close to the coupling-in grating. ### Claim 9 (depends on 8) The optical structure according to claim 8, wherein the third coupling-out grating comprises at least three sub-coupling-out gratings, the at least three sub-coupling-out gratings comprises a first sub-coupling-out grating partially located on one side of the eyebox, a second sub-coupling-out grating partially located on another side of the eyebox, and at least one sub-coupling-out grating completely located within the eyebox; a length of the first sub-coupling-out grating along an arrangement direction of all the sub-coupling-out gratings is greater than a sum of lengths of the at least one sub-coupling-out grating located within the eyebox along the arrangement direction of all the sub-coupling-out gratings; and a length of the second sub-coupling-out grating along the arrangement direction of all the sub-coupling-out gratings is greater than the sum of lengths of the at least one sub-coupling-out grating located within the eyebox along the arrangement direction of all the sub-coupling-out gratings. ### Claim 10 (depends on 8) The optical structure according to claim 8, wherein the first coupling-out grating comprises at least two sub-coupling-out gratings, a number of the sub-coupling-out gratings of the first coupling-out grating is equal to a number of the sub-coupling-out gratings of the third coupling-out grating, a junction of two adjacent sub-coupling-out gratings of the first coupling-out grating is located within the eyebox of the optical structure, and diffraction efficiency of the sub-coupling-out grating of the first coupling-out grating away from the coupling-in grating is greater than diffraction efficiency of the sub-coupling-out grating close to the coupling-in grating; the second coupling-out grating comprises at least two sub-coupling-out gratings, a number of the sub-coupling-out gratings of the second coupling-out grating is the same as a number of the sub-coupling-out gratings of the third coupling-out grating, a junction of two adjacent sub-coupling-out gratings of the second coupling-out grating is located within the eyebox of the optical structure, and diffraction efficiency of the sub-coupling-out grating of the second coupling-out grating away from the coupling-in grating is greater than diffraction efficiency of the sub-coupling-out grating close to the coupling-in grating. ### Claim 11 (depends on 1) The optical structure according to claim 1, wherein the second coupling-out grating and the first coupling-out grating are arranged axially symmetrically with respect to the third coupling-out grating, the second coupling-out grating is a two-dimensional grating with a plurality of second grids, and all the second grids of the second coupling-out grating have a same shape and arrangement as those of all the first grids of the first coupling-out grating. ### Claim 12 An optical structure, comprising: a waveguide; a first coupling-out grating, arranged on the waveguide; a second coupling-out grating, arranged on the waveguide; a third coupling-out grating, arranged on the waveguide, wherein the third coupling-out grating is located between the first coupling-out grating and the second coupling-out grating; and a coupling-in grating, arranged at a same side of the first coupling-out grating, the second coupling-out grating and the third coupling-out grating, wherein the coupling-in grating and the third coupling-out grating are arranged side by side; wherein the third coupling-out grating comprises at least two sub-coupling-out gratings, a junction of two adjacent sub-coupling-out gratings is located within an eyebox of the optical structure, and diffraction efficiency of the sub-coupling-out grating away from the coupling-in grating is greater than diffraction efficiency of the sub-coupling-out grating close to the coupling-in grating. ### Claim 13 (depends on 12) The optical structure according to claim 12, wherein at least a part of all the sub-coupling-out gratings is located within the eyebox. ### Claim 14 (depends on 13) The optical structure according to claim 13, wherein the third coupling-out grating comprises at least three sub-coupling-out gratings, and the at least three sub-coupling-out gratings comprise a first sub-coupling-out grating partially located on one side of the eyebox, a second sub-coupling-out grating partially located on another side of the eyebox, and at least one sub-coupling-out grating completely located within the eyebox; a length of the first sub-coupling-out grating along an arrangement direction of all the sub-coupling-out gratings is greater than a sum of lengths of the at least one sub-coupling-out grating located within the eyebox along the arrangement direction of all the sub-coupling-out gratings; and a length of the second sub-coupling-out grating along the arrangement direction of all the sub-coupling-out gratings is greater than the sum of lengths of the at least one sub-coupling-out grating located within the eyebox along the arrangement direction of all the sub-coupling-out gratings. ### Claim 15 (depends on 14) The optical structure according to claim 14, wherein a number of the sub-coupling-out gratings located completely within the eyebox is one, two or three, diffraction efficiency of all the sub-coupling-out grating increase proportionally along a direction from the sub-coupling-out grating closest to the coupling-in grating to the sub-coupling-out grating farthest from the coupling-in grating, or the first sub-coupling-out grating and the second sub-coupling-out grating are arranged symmetrically with respect to the sub-coupling-out grating completely located within the eyebox. ### Claim 16 (depends on 14) The optical structure according to claim 14, wherein a ratio of a length of the first sub-coupling-out grating or the second sub-coupling-out grating along the arrangement direction of all the sub-coupling-out gratings to a length of all the sub-coupling-out gratings is P1, a ratio of the length of all the sub-coupling-out gratings located completely within the eyebox along the arrangement direction of all the sub-coupling-out gratings to the length of all sub-coupling-out gratings is P2; and wherein P1 is greater than or equal to 30%, P1 is less than or equal to 45%, P2 is greater than or equal to 10%, and P2 is less than 30%. ### Claim 17 (depends on 12) The optical structure according to claim 12, wherein the first coupling-out grating comprises at least two sub-coupling-out gratings, and a number of the sub-coupling-out gratings of the first coupling-out grating is equal to a number of the sub-coupling-out gratings of the third coupling-out grating, a junction of two adjacent sub-coupling-out gratings of the first coupling-out grating is located within the eyebox of the optical structure, and diffraction efficiency of the sub-coupling-out grating of the first coupling-out grating away from the coupling-in grating is greater than diffraction efficiency of the sub-coupling-out grating close to the coupling-in grating; and the second coupling-out grating comprises at least two sub-coupling-out gratings, a number of the sub-coupling-out gratings of the second coupling-out grating is the same as a number of the sub-coupling-out gratings of the third coupling-out grating, a junction of two adjacent sub-coupling-out gratings of the second coupling-out grating is located within the eyebox of the optical structure, and diffraction efficiency of the sub-coupling-out of the second coupling-out grating away from the coupling-in grating is greater than the diffraction efficiency of the sub-coupling-out grating close to the coupling-in grating. ### Claim 18 (depends on 12) The optical structure according to claim 12, wherein the third coupling-out grating is a two-dimensional grating, the coupling-in grating is a one-dimensional grating, a grating period of the third coupling-out grating along an arrangement direction of all the sub-coupling-out gratings of the third coupling-out grating is twice a grating period of the coupling-in grating, the first coupling-out grating and the second coupling-out grating are both one-dimensional gratings, or both the first coupling-out grating and the second coupling-out grating are two-dimensional gratings; a refractive index of any one of the first coupling-out grating, the second coupling-out grating, the third coupling-out grating and the coupling-in grating to the waveguide is 1.5-3; periods of the first coupling-out grating, the second coupling-out grating and the coupling-in grating are equal, in response to the first coupling-out grating and the second coupling-out grating being one-dimensional gratings; and periods of the first coupling-out grating, the second coupling-out grating and the third coupling-out grating are equal, in response to the first coupling-out grating and the second coupling-out grating being two-dimensional gratings. ### Claim 19 An optical device, comprising: a projector, configured to provide augmented reality or virtual reality images; and a waveguide; a first coupling-out grating, arranged on the waveguide; a second coupling-out grating, arranged on the waveguide; and a third coupling-out grating, arranged on the waveguide, wherein the third coupling-out grating is located between the first coupling-out grating and the second coupling-out grating; wherein the first coupling-out grating is a two-dimensional grating with a plurality of first grids, the first grid has an asymmetric shape to allow light propagation efficiency of the first coupling-out grating along a first direction is higher than light propagation efficiency of the first coupling-out grating along a second direction; and wherein the first direction is a direction in which the first coupling-out grating faces the second coupling-out grating, and the first direction is opposite to the second direction. ### Claim 20 (depends on 19) The optical device according to claim 19, further comprising a coupling-in grating, wherein the coupling-in grating is arranged at a same side of the first coupling-out grating, the second coupling-out grating and the third coupling-out grating, and the coupling-in grating and the third coupling-out grating are arranged side by side; wherein the first grid comprises four vertices capable of forming a first diagonal line and a second diagonal line, a length of the first diagonal line is greater than a length of the second diagonal line, an angle between the first diagonal line and the third coupling-out grating along a third direction is an acute angle, and an angle between the second diagonal line and the third coupling-out grating along the third direction is an obtuse angle; and wherein the third direction is a direction in which the third coupling-out grating faces the coupling-in grating.