Multilayer thin film lithium-containing optical devices

Patent metadata

Field	Value
Publication number	US-12353071-B1
Application number	US-202418991092-A
Country	US
Kind code	B1
Filing date	Dec 20, 2024
Priority date	Dec 21, 2023
Publication date	Jul 8, 2025
Grant date	Jul 8, 2025

Abstract

An electro-optic device includes a substrate structure, a first layer, a second layer on the first layer, and a third layer on the second layer. The first layer includes a first thin film lithium-containing (TFLC) electro-optic material and having a first thickness. The second layer includes a second TFLC electro-optic material and has a second thickness. The third layer includes a third TFLC electro-optic material and having a third thickness. Electro-optic structure(s) of the electro-optic device includes the first layer, the second layer, and the third layer. In the electro-optic structure(s), the first layer has a first width, the second layer has a second width, and the third layer has a third width.

First claim

What is claimed is:

1. An electro-optic device, comprising:
a substrate structure;
a first layer on the substrate structure and including a first thin film lithium-containing (TFLC) electro-optic material having a first thickness;
a second layer on the first layer, the second layer including a second TFLC electro-optic material and having a second thickness; and
a third layer on the second layer, the third layer including a third TFLC electro-optic material and having a third thickness;
wherein at least one electro-optic structure of the electro-optic device includes the first layer, the second layer, and the third layer, the first layer having a first width in the at least one electro-optic structure, the second layer having a second width in the at least one electro-optic structure, and the third layer having a third width in the at least one electro-optic structure, the at least one electro-optic structure including a waveguide;
wherein a portion of the waveguide is configured with a bend, the third layer being omitted at the bend, a TE 0 to TM 0 mode conversion being reduced.

2. The electro-optic device of claim 1 , wherein the first layer has a first thickness of at least fifty nanometers and not more than three hundred and fifty nanometers, the second layer has a second thickness of at least two hundred and fifty nanometers and not more than five hundred nanometers, and wherein the third layer has a third thickness of at least three hundred and fifty nanometers and not more than 1.2 micrometers.

3. The electro-optic device of claim 2 , wherein the first TFLC electro-optic material, the second TFLC electro-optic material, and the third TFLC electro-optic material each includes at least one of thin film lithium niobate and thin film lithium tantalate.

4. The electro-optic device of claim 1 , further comprising:
at least one dielectric layer having at least one location selected from between the first layer and the second layer and between the second layer and the third layer.

5. The electro-optic device of claim 1 , wherein the at least one electro-optic structure includes at least one of a waveguide, a grating having a plurality of teeth, a mode converter, or a multi-mode interference coupler.

6. The electro-optic device of claim 5 , wherein the at least one electro-optic structure includes the waveguide, the third width being less than the second width, and the second width being less than the first width.

7. The electro-optic device of claim 6 , wherein the waveguide is a rib waveguide and wherein the first layer corresponds to a trench adjacent to the waveguide.

8. The electro-optic device of claim 6 , further comprising:
an electrode, a portion of the electrode being proximate to a portion of the waveguide;
wherein the first layer extends to the electrode for at least the portion of the waveguide.

9. The electro-optic device of claim 6 , further comprising:
an electrode, a portion of the electrode being proximate to a portion of the waveguide;
wherein the third layer has the third thickness for the portion of the waveguide and a fourth thickness distal from the portion of the waveguide, the third thickness being greater than the fourth thickness and being at least five hundred nanometers and not more than eight hundred nanometers.

10. The electro-optic device of claim 6 , wherein the waveguide includes a first portion having the first layer, the second layer, and the third layer, the waveguide also including a second portion having only the first layer and the second layer.

11. The electro-optic device of claim 6 , wherein a portion of the waveguide is configured with a bend having a bending radius of less than forty micrometers and greater than ten micrometers, the first width being not more than one micrometer greater than the second width at the bend.

12. The electro-optic device of claim 5 , wherein the at least one electro-optic structure includes the grating, wherein the second layer has a central axis, the third layer being offset from the central axis.

13. The electro-optic device of claim 1 , wherein the at least one electro-optic structure includes an aperture extending through at least the first layer.

14. The electro-optic device of claim 1 , further comprising:
an additional electro-optic structure, at least one of the additional electro-optic structure including only the first layer and the second layer or the additional electro-optic structure including only the first layer.

15. An electro-optic device, comprising:
a substrate structure;
a first electro-optic structure on the substrate structure, the first electro-optic structure including a first layer, a second layer on the first layer, and a third layer on the second layer, the first layer including a first thin film lithium-containing (TFLC) electro-optic material having a first thickness, the second layer including a second TFLC electro-optic material and having a second thickness, the third layer including a third TFLC electro-optic material and having a third thickness, the first electro-optic structure including a waveguide; and
a second electro-optic structure on the substrate structure, the second electro-optic structure including the first layer and at least a portion of the second layer but omitting the third layer, the second electro-optic structure including a bend in the waveguide, a TE 0 to TM 0 mode conversion being reduced for the second electro-optic structure.

16. The electro-optic device of claim 15 , further comprising:
a third electro-optic structure including at least a portion of the first layer but omitting the second layer and the third layer.

17. A method, comprising:
providing at least one electro-optic structure from at least one lithium-containing electro-optic layer on a substrate structure, the at least one electro-optic structure including a waveguide, the providing the at least one electro-optic structure including performing at least three etches of the at least one lithium-containing electro-optic layer such that the at least one electro-optic structure includes a first layer, a second layer on the first layer, and a third layer on the second layer, the first layer including a first thin film lithium-containing (TFLC) electro-optic material having a first thickness, the second layer including a second TFLC electro-optic material and having a second thickness, the third layer including a third TFLC electro-optic material and having a third thickness, the at least one lithium-containing electro-optic layer including the first TFLC electro-optic material, the second TFLC electro-optic material, and the third TFLC electro-optic material;
wherein the first layer has a first width in the first electro-optic structure, the second layer has a second width in the at least one electro-optic structure, and the third layer has a third width in the at least one electro-optic structure; and
wherein a portion of the waveguide is configured with a bend, the third layer being omitted at the bend, a TE 0 to TM 0 mode conversion being reduced.

18. The method of claim 17 , wherein the second TFLC electro-optic material is the same as the first TFLC electro-optic material, and the third TFLC electro-optic material is the same as the first TFLC electro-optic material.

19. The method of claim 18 , further comprising:
providing at least one dielectric layer having at least one location selected from between the first layer and the second layer and between the second layer and the third layer.

Assignees

• Hyperlight Corp

Inventors

• Holzgrafe Jeffrey Cole
• Kovach Miles Matthew
• Reimer Christian
• Zhang Mian

Classifications

• G02F2202/20

  LiNbO3, LiTaO3 · CPC title

• G02F2201/066

  channel; buried · CPC title

• G02F2201/05

  multimode · CPC title

• G02F2201/302

  grating coupler · CPC title

• G02F2201/063

  ridge; rib; strip loaded · CPC title