SURFACE WAVEGUIDE HAVING A TAPERED REGION AND METHOD OF FORMING

• US 20140105556A1
• Filed: 10/11/2013
• Published: 04/17/2014
• Est. Priority Date: 10/11/2012
• Status: Active Grant

• Current Assignee: OctroliX B.V.
• Original Assignee: OctroliX B.V.
• Inventors: Heideman, Rene Gerrit, Leinse, Arne
• Granted Patent: US 9,020,317 B2
• Time in Patent Office: Days
• US Class Current: 385/131
• CPC Class Codes: G02B 6/14 Mode converters
• CPC Class Codes: G02B 6/305 and having an integrated mode-size expanding section, e.g. tapered waveguide

Abstract

A method for forming a waveguide having a thin-core region, a thick-core region, and a transition region of tapered thickness between them is disclosed. The method comprises forming a lower core layer of a first material on a lower cladding, forming a thin central core layer of a second material on the first core layer, forming an upper core layer of the first material on the central core layer, and etching the upper core layer in an etchant such that it is removed from the thin-core region and its thickness monotonically changes from its as-deposited thickness to extinction across the transition region, where the central core layer protects the lower core layer from exposure to the etchant.

Claims

1. An article comprising a waveguide having a core, the core including:

a first layer comprising a first material, the first layer including a first tapered region having a thickness that changes monotonically from a first thickness to extinction; and

a second layer comprising the first material;

wherein the first layer and second layer collectively support propagation of light.

2. The article of claim 1, further comprising a third layer that includes a second material, the third layer being between the first layer and the second layer.

3. The article of claim 2, further comprising a substrate, wherein the second layer is between the substrate and the first layer.

4. The article of claim 2, wherein the first material comprises silicon nitride and the second material comprises a silicon oxide.

5. The article of claim 1, wherein the core includes a second tapered region, the second tapered region having a width that changes monotonically from a first width to a second width.

6. The article of claim 5, wherein the first tapered region and the second tapered region are co-located.

7. The article of claim 1, wherein the second layer has a second thickness that is thinner than the first thickness.

8. The article of claim 1, further comprising a substrate, wherein the first layer is between the substrate and the second layer.

9. A method for forming a waveguide, the method comprising:

providing a first layer that is disposed on a substrate, the first layer comprising a first material;

forming a second layer comprising the first material; and

forming a first tapered region in one of the first layer and second layer, the first tapered region having a thickness that changes monotonically from a first thickness to extinction.

10. The method of claim 9, further comprising forming a third layer comprising a second material, wherein the third layer is formed on the first layer and the second layer is formed on the third layer.

11. The method of claim 10, wherein the first tapered region is formed in the second layer.

12. The method of claim 10, wherein the first material comprises silicon nitride and the second material comprises a silicon oxide.

13. The method of claim 9, wherein the first tapered region is formed in the first layer, and wherein the first tapered region is formed prior to the formation of the second layer.

14. The method of claim 9, further comprising forming a second tapered region in at least one of the first layer and second layer, wherein the second tapered region has a width that changes monotonically from a first width to a second width.

15. The method of claim 14, wherein the second tapered region and the first tapered region are formed such that they are co-located.

16. A method for forming a waveguide, the method comprising:

providing a first cladding layer, the first cladding layer comprising a first silicon oxide;

forming a first core layer on the first cladding layer, the first core layer having a first thickness, and the first core layer comprising silicon nitride;

forming a second core layer above the first core layer, the second core layer having a second thickness, and the second core layer comprising silicon nitride;

forming a first tapered region in one of the first core layer and second core layer, the first tapered region having a thickness that changes monotonically from a third thickness to extinction; and

forming a second cladding layer on the second core layer, the second cladding layer comprising a second silicon oxide.

17. The method of claim 16, further comprising forming a third core layer that comprises a silicon oxide, wherein the third core layer is formed on the first core layer and the second core layer is formed on the third core layer.

18. The method of claim 17, wherein the first tapered region is formed in the second core layer.

19. The method of claim 17, wherein the first tapered region is formed in the first core layer.

20. The method of claim 16, further comprising forming a second tapered region in at least one of the first core layer and third core layer, wherein the second tapered region has a width that changes monotonically from a first width to a second width.