received by the International Bureau on 27 November 2017 (27.11.2017)

CLAIMS

1. A laser structure, comprising:

a substrate;

an active region arranged on the substrate;

a waveguide arranged on the active region, the waveguide comprising a first top surface and two first side surfaces, wherein the first top surface joins one of the two first side surfaces to form an acute angle in the waveguide; and

a first material deposited on the two first side surfaces of the waveguide.

2. The laser structure of claim 1, wherein the first top surface joins both of the two first side surfaces to form two acute angles in the waveguide.

3. The laser structure of claim 1, wherein the waveguide is formed with a first portion of a second material on the active region, wherein a second portion of the second material comprises two second top surfaces adjacent the two first side surfaces of the waveguide, respectively, wherein one of the two second top surfaces joins a respective one of the two first side surfaces to form an acute angle in the waveguide, and wherein the first material is deposited on the two second top surfaces.

4. The laser structure of claim 3, wherein the both of the second top surfaces join both of the two first side surfaces to form two acute angles in the waveguide.

5. The laser structure of claim 1, wherein the first material is one of MgO, MgF₂, Si0₂, or

6. The laser structure of claim 1, wherein the first material has a dielectric constant below 10 in a frequency range up to 50 GHz.

7. The laser structure of claim 1, wherein the first material is non-conducting.

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8. The laser structure of claim 1, wherein a third portion of the second material comprises a third top surface and a second side surface, wherein the third top surface joins the second side surface, wherein the second side surface joins one of the two second top surfaces, and the laser structure further comprises:

a first contact arranged on the third top surface; and

a second contact arranged on the substrate,

wherein the first contact is configured to bias the laser structure by delivering electrical current to the laser structure.

9. The laser structure of claim 1, further comprising at least one facet.

10. The laser structure of claim 9, wherein the at least one facet is formed on the active region.

11. A laser structure, comprising:

a substrate;

an active region arranged on the substrate;

a waveguide arranged on the active region, the waveguide comprising a first top surface and two first side surfaces, wherein the first top surface joins the two first side surfaces to form two acute angles in the waveguide;

air gaps formed adjacent to the two first side surfaces; and

a metal layer arranged as a bridge over the air gaps.

12. The laser structure of claim 11, wherein the waveguide is formed with a first portion of a material on the active region, wherein a second portion of the material comprises two second top surfaces adjacent the two first side surfaces of the waveguide, respectively, wherein both of the second top surfaces join both of the two first side surfaces to form two acute angles in the waveguide.

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13. The laser structure of claim 11, further comprising a first contact arranged on the metal layer, wherein the first contact is configured to bias the laser structure by delivering electrical current to the laser structure.

14. The laser structure of claim 11, further comprising at least one facet.

15. The laser structure of claim 14, wherein the at least one facet is formed on the active region.

16. A method of fabricating a laser structure, comprising:

arranging an active region on a substrate;

arranging a waveguide on the active region, the waveguide comprising a first top surface and two first side surfaces, wherein the first top surface joins the two first side surfaces to form two acute angles in the waveguide;

depositing a polymer on at least the two first side surfaces;

depositing at least one layer of resist on the polymer;

depositing a metal layer on the at least one layer of resist; and

removing the deposited polymer and the deposited at least one layer of resist.

17. The method of claim 16, wherein the waveguide is formed with a first portion of a material on the active region, wherein a second portion of the material comprises two second top surfaces adjacent the two first side surfaces of the waveguide, respectively, wherein both of the second top surfaces join both of the two first side surfaces to form two acute angles in the waveguide.

18. The method of claim 16, further comprising arranging a first contact on the metal layer, wherein the first contact is configured to bias the laser structure by delivering electrical current to the laser structure.

19. The method of claim 16, further comprising forming at least one facet on the active region.

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20. The method of claim 19, wherein the at least one facet is formed by etching.

21. A fixture for electron beam evaporation, the fixture comprising:

a wafer plate configured to support a laser structure; and

an integrated heater configured to emit heat at an evaporation temperature, wherein the heat emitted by the integrated heater is adjustable and an angle of the fixture is adjustable.

22. The fixture of claim 21, wherein the wafer plate is further configured to orient the laser structure relative to an evaporant.

23. The fixture of claim 21, wherein the orientation of the laser structure subjects at least one ridge of the laser structure to the evaporant.

24. The fixture of claim 21, wherein the orientation of the laser structure is varied based on an angle of at least one ridge of the laser structure.