Waveguides with high index materials and methods of fabrication thereof

Patent metadata

Field	Value
Publication number	US-2024255763-A1
Application number	US-202418622925-A
Country	US
Kind code	A1
Filing date	Mar 30, 2024
Priority date	Mar 12, 2019
Publication date	Aug 1, 2024
Grant date	—

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.

First claim

What is claimed is:

1 . An optical device comprising:
a substrate comprising a first material having a first refractive index greater than about 2.0, wherein the substrate comprises a waveguide that is transparent to visible light; a plurality of diffractive features formed on the substrate, the diffractive features formed of a second material having a second refractive index lower than the first refractive index; and a third material disposed over the plurality of diffractive features, the third material having a third refractive index higher than the second refractive index.

2 . The optical device of claim 1 , wherein the first material comprises at least one of lithium niobate or silicon carbide.

3 . The optical device of claim 1 , wherein the first refractive index is at least about 2.3.

4 . The optical device of claim 1 , wherein the second material comprises photoresist.

5 . The optical device of claim 1 , wherein the second refractive index is less than about 1.8.

6 . The optical device of claim 1 , wherein the second refractive index is about 1.5.

7 . The optical device of claim 1 , wherein the second refractive index is between about 1.7 and about 1.8.

8 . The optical device of claim 1 , wherein the third refractive index is at least about 2.3.

9 . The optical device of claim 1 , wherein the third material comprises at least one of lithium niobate or silicon carbide.

10 . The optical device of claim 1 , wherein the plurality of diffractive features comprises a blazed diffractive grating.

11 . The optical device of claim 1 , wherein the plurality of diffractive features are asymmetrically shaped.

12 . The optical device of claim 1 , wherein more of the third material is on a first side of at least one of the diffractive features than on a second side of the at least one of the diffractive features.

13 . The optical device of claim 1 , wherein the plurality of diffractive features are arranged in a one-dimensional array.

14 . The optical device of claim 1 , wherein the plurality of diffractive features are arranged in a two-dimensional array.

15 . The optical device of claim 1 , wherein the plurality of diffractive features are included in an in-coupling optical element arranged to receive light and couple the light into the waveguide to be guided therein.

16 . The optical device of claim 1 , wherein the plurality of diffractive features are included in an out-coupling optical element arranged to couple, out of the waveguide, at least a portion of light being guided within the waveguide.

Assignees

• Magic Leap Inc

Inventors

• Singh Vikramjit
• Luo Kang
• Vaughn Michal Beau Dennison
• Bhargava Samarth
• Yang Shuqiang
• Miller Michael Nevin
• Xu Frank Y
• Klug Michael Anthony
• Messer Kevin
• Tekolste Robert D
• Deng Xiaopei
• Li Xiao

Classifications

• B29D11/00769

  Producing diffraction gratings · CPC title

• G02B6/34

  utilising prism or grating {(G02B6/293 takes precedence)} · CPC title

• G02B2027/0125

  Field-of-view increase by wavefront division · CPC title

• G02B2027/0118

  comprising devices for improving the contrast of the display / brillance control visibility · CPC title

• G02B6/0076

  Stacked arrangements of multiple light guides of the same or different cross-sectional area · CPC title