公开(公告)号：US20240329290A1

公开(公告)日：2024-10-03

申请号：US18529322

申请日：2023-12-05

Applicant: Meta Platforms Technologies, LLC

Inventor： Richard Farrell ,  Bo Zhao ,  Siddharth Buddhiraju ,  Nihar Ranjan Mohanty ,  Keith Rozenburg ,  Zhaohui Yang

IPC: F21V8/00 ,  G02B27/01

CPC classification number: G02B6/0016 ,  G02B6/0035 ,  G02B6/0065 ,  G02B27/0172 ,  G02B2027/0178

Abstract: A bilayer binary 2D surface relief grating includes a primary grating layer having an array of primary grating elements, and a secondary grating layer having an array of secondary grating elements overlying the primary grating layer, where the secondary grating elements are at least partially laterally offset from the primary grating elements. A method of manufacturing such a surface relief grating includes forming a low refractive index layer over a substrate, the low refractive index layer including a primary sub-layer having an array of primary openings and a secondary sub-layer overlying the primary sub-layer and having an array of secondary openings, where the secondary openings are at least partially laterally offset from the primary openings, and forming a high refractive index layer within the primary and secondary openings.

公开(公告)号：US20230288705A1

公开(公告)日：2023-09-14

申请号：US17693187

申请日：2022-03-11

Applicant: Meta Platforms Technologies, LLC

Inventor： Haiwen Wang ,  Yu Shi ,  Siddharth Buddhiraju ,  Hee Yoon Lee

IPC: G02B27/01 ,  F21V8/00 ,  G02B5/18

CPC classification number: G02B27/0172 ,  G02B6/005 ,  G02B5/1842

Abstract: An output grating for waveguide of a head-mounted display is configured to suppress the (1, 1) diffraction order of the output grating. The grating has a design of two or more materials having different refractive indices. The design is repeated periodically in a first dimension and repeated periodically in a second dimension, to form a two-dimensional pattern. A refractive index of the two-dimensional pattern is approximated by a two-dimensional Fourier series comprising a first coefficient of order (1, 0), a second coefficient of order (0, 1), and a third coefficient of order (1, 1). The third coefficient is less than half the first coefficient and less than half the second coefficient, such that light from the (1, 1) diffraction order of the grating is suppressed.

公开(公告)号：US11656464B2

公开(公告)日：2023-05-23

申请号：US17203056

申请日：2021-03-16

Applicant: Meta Platforms Technologies, LLC

Inventor： Siddharth Buddhiraju ,  Hee Yoon Lee ,  Pasi Saarikko

IPC: G02B27/01 ,  F21V8/00

CPC classification number: G02B27/0172 ,  G02B6/0016 ,  G02B6/0035 ,  G02B6/0056 ,  G02B2027/0112

Abstract: A pupil-replicating waveguide includes a high-index substrate and a low-index substrate coupled by an intermediate layer between the substrates. The refractive index of the intermediate layer is lower than the refractive index of the low-index substrate. The intermediate layer prevents highly oblique rays of image light from entering the low-index substrate, thereby reducing intensity drops in the field of view conveyed by the pupil-replicating waveguide, the intensity drops caused by insufficient replication of the highly oblique rays in the low-index substrate.