Waveguide couplers for multi-mode waveguides

Patent metadata

Field	Value
Publication number	US-12372725-B1
Application number	US-202318228619-A
Country	US
Kind code	B1
Filing date	Jul 31, 2023
Priority date	Dec 7, 2018
Publication date	Jul 29, 2025
Grant date	Jul 29, 2025

Abstract

An optical coupler includes a first waveguide including a first multi-mode waveguide section having a cross-section characterized by a first height and a first width that is greater than the first height and a second waveguide including a second multi-mode waveguide section having a cross-section characterized by a second height and a second width that is greater than the second height. The first multi-mode waveguide section is positioned adjacent to the second multi-mode waveguide section at least partially above or below the second multi-mode waveguide so that light entering the first multi-mode waveguide section is coupled from the first multi-mode waveguide section to the second multi-mode waveguide section. Methods for coupling light between waveguides with the optical coupler and optical devices that include the optical coupler are also described.

First claim

What is claimed is:

1. An optical coupler, comprising:
a first waveguide including a first multi-mode waveguide section; and
a second waveguide that is distinct and separate from the first waveguide, the second waveguide including a second multi-mode waveguide section that is distinct and separate from the first multi-mode waveguide section, wherein:
the first multi-mode waveguide section has a cross-section characterized by a first height and a first width that is greater than the first height;
the second multi-mode waveguide section has a cross-section characterized by a second height and a second width that is greater than the second height;
the first multi-mode waveguide section is positioned adjacent to the second multi-mode waveguide section at least partially above or below the second multi-mode waveguide section so that light entering the first multi-mode waveguide section is coupled from the first multi-mode waveguide section to the second multi-mode waveguide section; and
the first multi-mode waveguide section and the second multi-mode waveguide section are separated by a first edge-to-edge distance so that light entering the first multi-mode waveguide section in a fundamental mode is coupled from the first multi-mode waveguide section to the second multi-mode waveguide section while remaining in the fundamental mode.

2. The optical coupler of claim 1 , wherein:
the first width is at least three times the first height; and
the second width is at least three times the second height.

3. The optical coupler of claim 1 , wherein:
the first waveguide includes a third multi-mode waveguide section that is distinct from, and mutually exclusive to, the first multi-mode waveguide section so that light propagating in the third multi-mode waveguide section propagates toward the first multi-mode waveguide section; and
the second waveguide includes a fourth multi-mode waveguide section that is distinct from, and mutually exclusive to, the second multi-mode waveguide section so that light propagating in the fourth multi-mode waveguide section propagates toward the second multi-mode waveguide section.

4. The optical coupler of claim 3 , wherein:
the first waveguide includes a fifth multi-mode waveguide section that is coupled to the first multi-mode waveguide section on a first end and to the third multi-mode waveguide section on a second end that is opposite to the first end; and
the second waveguide includes a sixth multi-mode waveguide section that is coupled to the second multi-mode waveguide section on a first end and to the fourth multi-mode waveguide section on a second end that is opposite to the first end,
wherein at least one of the fifth multi-mode waveguide section and the sixth multi-mode waveguide section is curved.

5. The optical coupler of claim 4 , wherein:
the first waveguide includes a seventh multi-mode waveguide section that is distinct from, and mutually exclusive to, the first multi-mode waveguide section so that light propagating in the first multi-mode waveguide section propagates toward the seventh multi-mode waveguide section; and
the second waveguide includes an eighth multi-mode waveguide section that is distinct from, and mutually exclusive to, the second multi-mode waveguide section so that light propagating in the second multi-mode waveguide section propagates toward the eighth multi-mode waveguide section.

6. The optical coupler of claim 5 , wherein:
the first waveguide includes a ninth multi-mode waveguide section that is coupled to the first multi-mode waveguide section on a first end and to the seventh multi-mode waveguide section on a second end that is opposite to the first end; and
the second waveguide includes a tenth multi-mode waveguide section that is coupled to the second multi-mode waveguide section on a first end and to the eighth multi-mode waveguide section on a second end that is opposite to the first end,
wherein at least one of the ninth multi-mode waveguide section and the tenth multi-mode waveguide section is curved.

7. The optical coupler of claim 1 , wherein:
the first waveguide includes a first single-mode input waveguide section adiabatically coupled to the first multi-mode waveguide section so that the first multi-mode waveguide section receives light from the first single-mode input waveguide section; and
the second waveguide includes a second single-mode input waveguide section adiabatically coupled to the second multi-mode waveguide section so that the second multi-mode waveguide section receives light from the second single-mode input waveguide section.

8. The optical coupler of claim 7 , further comprising:
a first tapered waveguide section, in the first waveguide, configured to enable the adiabatic coupling of the first single-mode input waveguide section to the first multi-mode waveguide section; and
a second tapered waveguide section, in the second waveguide, configured to enable the adiabatic coupling of the second single-mode input waveguide section to the second multi-mode waveguide section.

9. The optical coupler of claim 8 , further comprising:
in the first waveguide:
a first single-mode output waveguide section adiabatically coupled to the first multi-mode waveguide section so that the first single-mode output waveguide section receives light from the first multi-mode waveguide section; and
a third tapered waveguide section configured to enable the adiabatic coupling of the first multi-mode waveguide section to the first single-mode output waveguide section; and

in the second waveguide:
a second single-mode output waveguide section adiabatically coupled to the second multi-mode waveguide section so that the second single-mode output waveguide section receives light from the second multi-mode waveguide section; and
a fourth tapered waveguide section configured to enable the adiabatic coupling of the second multi-mode waveguide section to the second single-mode output waveguide section.

10. The optical coupler of claim 1 , wherein the first multi-mode waveguide section and the second multi-mode waveguide section are parallel to each other.

11. A multi-channel multi-mode optical coupler, comprising:
two or more multi-mode optical couplers, including a first multi-mode optical coupler that corresponds to the optical coupler of claim 1 , wherein:
the first waveguide is located in a first layer of material;
the second waveguide is located in a second layer of material that is distinct and separate from the first layer of material; and
the first multi-mode waveguide section is positioned adjacent to the second multi-mode waveguide section.

12. The multi-channel multi-mode optical coupler of claim 11 , wherein:
the two or more multi-mode optical couplers also include a second multi-mode optical coupler that includes:
a third waveguide including a third multi-mode waveguide section, the third waveguide being located in the first layer of material; and
a fourth waveguide that is distinct and separate from the third waveguide, the fourth waveguide including a fourth multi-mode waveguide section and being located in the second layer of material;

the third multi-mode waveguide section is positioned adjacent to the fourth multi-mode waveguide section; and
a portion of the second waveguide is positioned adjacent to a portion of the third waveguide for coupling light from the second waveguide to the third waveguide.

13. The multi-channel multi-mode optical coupler of claim 12 , wherein:
the two or more multi-mode optical couplers also include a third multi-mode optical coupler and a fourth multi-mode optical coupler;
the third multi-mode optical c

Assignees

• Psiquantum Corp

Inventors

• Thompson Mark

Classifications

• G02F1/225

  in an optical waveguide structure · CPC title

• G02B6/125

  Bends, branchings or intersections · CPC title

• G02B6/12002

  Three-dimensional structures · CPC title

• G02F1/212

  Mach-Zehnder type · CPC title

• G02F1/3135

  Vertical structure · CPC title