Laser with a gain medium layer doped with a rare earth metal with upper and lower light-confining features

Patent metadata

Field	Value
Publication number	US-11088503-B2
Application number	US-201916525878-A
Country	US
Kind code	B2
Filing date	Jul 30, 2019
Priority date	Jul 30, 2019
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

Abstract

One illustrative laser disclosed herein includes a gain medium layer having a first width in a transverse direction that is orthogonal to a laser emitting direction of the laser, and an upper light-confining structure positioned above an upper surface of the gain medium layer, wherein the upper light-confining structure has a second width in the transverse direction that is equal to or less than the first width and comprises at least one material having an index of refraction that is at least 2.0. The laser also includes a lower light-confining structure positioned below a lower surface of the gain medium layer, wherein the lower light-confining structure has a third width in the transverse direction that is equal to or less than the first width and comprises at least one material having an index of refraction that is at least 2.0.

First claim

The invention claimed is:

1. A laser having a laser emitting direction and a transverse direction that is orthogonal to the laser emitting direction, the laser comprising:
a gain medium layer doped with a rare earth metal, the gain medium layer having an upper surface, a lower surface and a first width in the transverse direction;
first light-confining structure having a lower surface that is positioned on and in contact with the upper surface of the gain medium layer, the first light-confining structure having a second width in the transverse direction that is at most equal to the first width, wherein the first light-confining structure comprises at least one material having an index of refraction that is at least 2.0;
a first insulating material positioned above the upper surface of the gain medium layer;
a second light-confining structure positioned below the lower surface of the gain medium layer, the second light-confining structure having a third width in the transverse direction that is at most equal to the first width, wherein the second light-confining structure comprises at least one material having an index of refraction that is at least 2.0; and
a second insulating material positioned below the lower surface of the gain medium layer,
wherein the indexes of refraction of the first and second light-confining structures are greater than an index of refraction of the gain medium layer, and wherein the index of refraction of the gain medium layer is greater than indexes of refraction of the first and second insulating materials.

2. The laser of claim 1 , wherein the second width is substantially equal to the third width.

3. The laser of claim 1 , wherein an upper surface of the second light-confining structure is positioned on and contact with the lower surface of the gain medium layer.

4. The laser of claim 1 , wherein the gain medium layer has a first axial length in the laser emitting direction, the first light-confining structure has a second axial length in the laser emitting direction, and the second light-confining structure has a third axial length in the laser emitting direction, wherein the first, second and third axial lengths are the same.

5. The laser of claim 4 , wherein the second and third axial lengths are less than the first axial length.

6. The laser of claim 1 , wherein the gain medium layer has one of a substantially rectangular configuration or a substantially trapezoidal configuration when viewed from above.

7. The laser of claim 1 , wherein the first light-confining structure and the second light-confining structure comprise at least one layer of a same material.

8. The laser of claim 1 , wherein the first light-confining structure consists of a single layer of material that is continuous across the second width and the second light-confining structure consists of a single layer of material that is continuous across the third width.

9. The laser of claim 1 , wherein the first light-confining structure comprises a plurality of first patterned features with a lateral space between adjacent first patterned features.

10. The laser of claim 1 , wherein the first light-confining structure comprises a plurality of vertically spaced apart layers of material each having an index of refraction of at least 2.

11. The laser of claim 10 , wherein each of the plurality of vertically spaced apart layers of material comprises a plurality of first patterned features with a lateral space between adjacent first patterned features.

12. The laser of claim 1 , wherein the second light-confining structure comprises a plurality of vertically spaced apart layers of material each having an index of refraction of at least 2.

13. The laser of claim 1 , wherein the first light-confining structure and the second light-confining structure comprise one of silicon, silicon nitride, AN or SiON and the gain medium layer comprises one of aluminum oxide (Al 2 O 3 ), zinc oxide (ZnO), titanium dioxide (TiO 2 ), or bismuth-oxide (Bi 2 O 3 )) that is doped with a rare earth metal.

14. A laser having a laser emitting direction and a transverse direction that is orthogonal to the laser emitting direction, the laser comprising:
a gain medium layer doped with a rare earth metal, the gain medium layer having an upper surface, a lower surface and a first width in the transverse direction;
first light-confining structure having a lower surface that is positioned on and in contact with the upper surface of the gain medium layer, the first light-confining structure having a second width in the transverse direction that is less than the first width, wherein the first light-confining structure comprises at least one material having an index of refraction that is at least 2.0;
a first insulating material positioned above the upper surface of the gain medium layer;
a second light-confining structure positioned below the lower surface of the gain medium layer, the second light-confining structure having a third width in the transverse direction that is less than the first width, wherein the second light-confining structure comprises at least one material having an index of refraction that is at least 2.0; and
a second insulating material positioned below the lower surface of the gain medium layer,
wherein the first light-confining structure and the second light-confining structure each has an index of refraction greater than an index of refraction of the gain medium layer, and wherein the index of refraction of the gain medium layer is greater than each index of refraction of the first insulating material and the second insulating material.

15. The laser of claim 14 , wherein the second width is substantially equal to the third width and wherein the gain medium layer has a first axial length in the laser emitting direction, the first light-confining structure has a second axial length in the laser emitting direction, and the second light-confining structure has a third axial length in the laser emitting direction, wherein the first, second and third axial lengths are the same.

16. The laser of claim 14 , wherein an upper surface of the second light-confining structure is positioned on and in contact with the lower surface of the gain medium layer.

17. The laser of claim 14 , wherein the first light-confining structure consists of a single layer of material that is continuous across the second width and the second light-confining structure consists of a single layer of material that is continuous across the third width.

18. The laser of claim 14 , wherein the first light-confining structure comprises a plurality of first patterned features with a lateral space between adjacent first patterned features.

19. The laser of claim 14 , wherein the first light-confining structure comprises a plurality of vertically spaced apart layers of material each having an index of refraction of at least 2, wherein the lowermost layer of the plurality of vertically spaced apart layers of material is positioned on and in contact with the upper surface of the gain medium layer.

20. The laser of claim 14 , wherein the first light-confining structure and the second light-confining structure comprise at least one layer of a same material.

Assignees

• Globalfoundries Us Inc

Inventors

• Bian Yusheng
• Jacob Ajey Poovannummoottil

Classifications

• H01S3/161

  holmium · CPC title

• H01S3/1603

  rare earth · CPC title

• H01S3/1618

  ytterbium · CPC title

• H01S3/0804

  Transverse or lateral modes · CPC title

• H01S3/0637 Primary

  Integrated lateral waveguide, e.g. the active waveguide is integrated on a substrate made by Si on insulator technology (Si/SiO2) · CPC title