Optical eyepiece using single-sided patterning of grating couplers

Patent metadata

Field	Value
Publication number	US-12535671-B2
Application number	US-202318172890-A
Country	US
Kind code	B2
Filing date	Feb 22, 2023
Priority date	Jun 14, 2019
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

An eyepiece includes a substrate and an in-coupling grating patterned on a single side of the substrate. A first grating coupler is patterned on the single side of the substrate and has a first grating pattern. The first grating coupler is optically coupled to the in-coupling grating. A second grating coupler is patterned on the single side of the substrate adjacent to the first grating coupler. The second grating coupler has a second grating pattern different from the first grating pattern. The second grating coupler is optically coupled to the in-coupling grating.

First claim

The invention claimed is:

1 . An eyepiece comprising:
a substrate; an in-coupling grating imprinted on a single side of the substrate; and a grating coupler imprinted on the single side of the substrate and optically coupled to the in-coupling grating, wherein the grating coupler comprises a plurality of tiles defining an exit pupil expander (EPE) of the eyepiece, wherein each tile of the plurality of tiles comprises a plurality of protrusions.

2 . The eyepiece of claim 1 , wherein each tile of the plurality of tiles comprises a first grating pattern, wherein a grating region is interspersed among the plurality of tiles, and comprises a second grating pattern that is different from the first grating pattern.

3 . The eyepiece of claim 2 , wherein the grating region defines an orthogonal pupil expander (OPE) of the eyepiece.

4 . The eyepiece of claim 2 , wherein the in-coupling grating comprises a first set of parallel ridges, and the grating region comprises a second set of parallel ridges orthogonal to the first set of parallel ridges.

5 . The eyepiece of claim 1 , wherein the grating coupler is configured to receive light diffracted by the in-coupling grating and reduce a brightness of light emitted by a center region of the grating coupler.

6 . The eyepiece of claim 1 , wherein the grating coupler is configured to receive light diffracted by the in-coupling grating and diffuse light emitted by a center region of the grating coupler.

7 . The eyepiece of claim 1 , wherein each protrusion of the plurality of protrusions has one or more sidewalls.

8 . The eyepiece of claim 7 , wherein each sidewall of the one or more sidewalls is oriented at a different angle to the substrate.

9 . The eyepiece of claim 1 , wherein each protrusion of the plurality of protrusions includes two intersecting ridges oriented in two different directions.

10 . The eyepiece of claim 1 , wherein each protrusion of the plurality of protrusions has a cylindrical or ellipsoidal shape.

11 . The eyepiece of claim 1 , wherein each protrusion of the plurality of protrusions has at least one rectangular, circular, triangular, or polygonal surface.

12 . The eyepiece of claim 1 , wherein each tile of the plurality of tiles comprises a plurality of cuboids.

13 . The eyepiece of claim 12 , wherein each cuboid of the plurality of cuboids has a different height.

14 . The eyepiece of claim 1 , wherein an area of each tile of the plurality of tiles decreases as a position of the tile changes from a center of the grating coupler to a boundary of the grating coupler.

15 . The eyepiece of claim 1 , wherein an area of each tile of the plurality of tiles increases as a position of the tile changes from a first boundary of the grating coupler to a second boundary of the grating coupler.

16 . The eyepiece of claim 1 , wherein each tile of the plurality of tiles has at least one of a rectangular shape, a circular shape, an elliptical shape, a polygonal shape, or a hexagonal shape.

17 . The eyepiece of claim 1 , wherein each tile of the plurality of tiles comprises a plurality of recesses.

18 . The eyepiece of claim 17 , wherein the plurality of recesses have a refractive index greater than 1.4.

19 . The eyepiece of claim 17 , wherein at least one of a width or a length of each recess of the plurality of recesses is in a range from 5 nm to 800 nm.

20 . The eyepiece of claim 17 , wherein a cross-section of each recess of the plurality of recesses has a triangular, sawtooth, or staircase shape.

21 . An eyepiece comprising:
a substrate; an in-coupling grating imprinted on a single side of the substrate; and a grating coupler imprinted on the single side of the substrate and optically coupled to the in-coupling grating, wherein the grating coupler comprises a plurality of tiles defining an exit pupil expander (EPE) of the eyepiece, wherein each tile of the plurality of tiles comprises a plurality of cuboids.

22 . The eyepiece of claim 21 , wherein each cuboid of the plurality of cuboids has a different height.

23 . An eyepiece comprising:
a substrate; an in-coupling grating imprinted on a single side of the substrate; and a grating coupler imprinted on the single side of the substrate and optically coupled to the in-coupling grating, wherein the grating coupler comprises a plurality of tiles defining an exit pupil expander (EPE) of the eyepiece, wherein the grating coupler is configured to receive light diffracted by the in-coupling grating and diffuse light emitted by a center region of the grating coupler.

24 . The eyepiece of claim 23 , wherein each tile of the plurality of tiles comprises a plurality of recesses.

25 . The eyepiece of claim 23 , wherein an area of each tile of the plurality of tiles increases or decreases as a position of the tile changes from a first location of the grating coupler to a second location of the grating coupler.

26 . An eyepiece comprising:
a substrate; an in-coupling grating imprinted on a single side of the substrate; and a grating coupler imprinted on the single side of the substrate and optically coupled to the in-coupling grating, wherein the grating coupler comprises a plurality of tiles defining an exit pupil expander (EPE) of the eyepiece, wherein the grating coupler is configured to receive light diffracted by the in-coupling grating and diffuse light emitted by a center region of the grating coupler, wherein each tile of the plurality of tiles comprises a first grating pattern, wherein a grating region is interspersed among the plurality of tiles, and comprises a second grating pattern that is different from the first grating pattern, wherein the in-coupling grating comprises a first set of parallel ridges, and the grating region comprises a second set of parallel ridges orthogonal to the first set of parallel ridges.

27 . The eyepiece of claim 26 , wherein each tile of the plurality of tiles comprises a plurality of recesses.

28 . The eyepiece of claim 26 , wherein an area of each tile of the plurality of tiles increases or decreases as a position of the tile changes from a first location of the grating coupler to a second location of the grating coupler.

29 . An eyepiece comprising:
a substrate; an in-coupling grating imprinted on a single side of the substrate; and a grating coupler imprinted on the single side of the substrate and optically coupled to the in-coupling grating, wherein the grating coupler comprises a plurality of tiles defining an exit pupil expander (EPE) of the eyepiece, wherein an area of each tile of the plurality of tiles decreases as a position of the tile changes from a center of the grating coupler to a boundary of the grating coupler.

30 . The eyepiece of claim 29 , wherein each tile of the plurality of tiles comprises a plurality of recesses.

31 . The eyepiece of claim 29 , wherein each tile of the plurality of tiles comprises a plurality of cuboids.

32 . An eyepiece comprising:
a substrate; an in-coupling grating imprinted on a single side of the substrate; and a grating coupler imprinted on the single side of the substrate and optically coupled to the in-coupling grating, wherein the grating coupler comprises a plurality of tiles defining an exit pupil expander (EPE)

Assignees

• Magic Leap Inc

Inventors

• Luo Kang
• Singh Vikramjit
• Pi Nai-Wen
• Yang Shuqiang
• Xu Frank Y

Classifications

• G02B6/29329

  Diffractive elements operating in transmission · CPC title

• G02B6/2935

  Mach-Zehnder configuration, i.e. comprising separate splitting and combining means · CPC title

• G02B6/29334

  Grating-assisted evanescent light guide couplers, i.e. comprising grating at or functionally associated with the coupling region between the light guides, e.g. with a grating positioned where light fields overlap in the coupler · CPC title

• G02B25/001 Primary

  Eyepieces · CPC title

• G02B27/01

  Head-up displays · CPC title