Optical connection structure

Patent metadata

Field	Value
Publication number	US-11480732-B2
Application number	US-201917288079-A
Country	US
Kind code	B2
Filing date	Nov 19, 2019
Priority date	Dec 3, 2018
Publication date	Oct 25, 2022
Grant date	Oct 25, 2022

Abstract

An optical connection structure includes a PLC that is an optical waveguide chip including an optical waveguide and at least one groove formed on a substrate, and at least one optical fiber that is fitted into the at least one groove of the PLC. The PLC includes the optical waveguide, at least one grating coupler that is optically connected to the optical waveguide, and the at least one groove formed at a position in a vicinity of the at least one grating coupler in a cladding layer in which the optical waveguide is formed. An optical fiber of the at least one optical fiber is fitted into a groove of the at least one groove such that an end surface of the optical fiber is located in a vicinity of a grating coupler of the at least one grating coupler, the optical fiber being optically connected to the grating coupler.

First claim

The invention claimed is:

1. An optical connection structure comprising:
an optical waveguide chip comprising an optical waveguide on a substrate, a grating coupler optically connected to the optical waveguide, and a groove; and
an optical fiber that is fitted into the groove of the optical waveguide chip, wherein the groove is disposed in a topmost surface of a cladding layer in which the optical waveguide is disposed, wherein the groove extends at least to a level of a bottom surface of the grating coupler, and wherein the optical fiber is optically connected to the grating coupler.

2. The optical connection structure according to claim 1 , wherein the optical fiber adhered to the optical waveguide chip with an optical adhesive.

3. The optical connection structure according to claim 2 , wherein the optical adhesive covers a distal end of the optical fiber fitted into the groove and covers the grating coupler.

4. The optical connection structure according claim 1 , wherein the groove extends to an end surface of the optical waveguide chip along an in-plane direction of the cladding layer.

5. The optical connection structure according to claim 1 , wherein:
the groove extends along an in-plane direction of the cladding layer to end of the groove at a position at which the groove does not reach an end surface of the optical waveguide chip; and
the optical fiber is fitted into the groove so as to be at a slanted include with respect to a surface of the optical waveguide chip on which the grating coupler is disposed.

6. The optical connection structure according to claim 5 , wherein the groove has a planar shape in a top view, with a rectangular shape on a side closer to the grating coupler and an elliptical hemisphere shape on a side closer to the end surface of the optical waveguide chip, the planar shape being obtained by combining the rectangular shape and the elliptical hemisphere shape such that a width of the rectangular shape coincides with a shorter diameter of the elliptical hemisphere shape.

7. The optical connection structure according to claim 1 , wherein the optical fiber is a thermally-expanded core optical fiber, a lensed fiber, an obliquely cut fiber, a multiple-core fiber, or a multicore fiber.

8. The optical connection structure according to claim 1 , wherein the groove extends completely through the cladding layer and exposes a lower layer different from the cladding layer, the lower layer having an upper surface serving as a bottom surface of the groove.

9. A method comprising:
providing an optical waveguide chip comprising an optical waveguide on a substrate, a grating coupler optically connected to the optical waveguide, and a groove; and
fitting an optical fiber into the groove of the optical waveguide chip, wherein the groove is disposed in a topmost surface of a cladding layer in which the optical waveguide is disposed, wherein the groove extends at least to a level of a bottom surface of the grating coupler, and wherein the optical fiber is optically connected to the grating coupler.

10. The method according to claim 9 , further comprising adhering the optical fiber into the groove of the optical waveguide chip with an optical adhesive.

11. The method according to claim 10 , wherein the optical adhesive covers a distal end of the optical fiber fitted into the groove and covers the grating coupler.

12. The method according to claim 9 , wherein the groove extends to an end surface of the optical waveguide chip along an in-plane direction of the cladding layer.

13. The method according to claim 9 , wherein:
the groove extends along an in-plane direction of the cladding layer to end of the groove at a position at which the groove does not reach an end surface of the optical waveguide chip; and
the optical fiber is fitted into the groove so as to be at a slanted include with respect to a surface of the optical waveguide chip on which the grating coupler is disposed.

14. The method according to claim 13 , wherein the groove has a planar shape in a top view, with a rectangular shape on a side closer to the grating coupler and an elliptical hemisphere shape on a side closer to the end surface of the optical waveguide chip, the planar shape being obtained by combining the rectangular shape and the elliptical hemisphere shape such that a width of the rectangular shape coincides with a shorter diameter of the elliptical hemisphere shape.

15. The method according to claim 9 , wherein the optical fiber is a thermally-expanded core optical fiber, a lensed fiber, an obliquely cut fiber, a multiple-core fiber, or a multicore fiber.

16. The method according to claim 9 , wherein the groove extends completely through the cladding layer and exposes a lower layer different from the cladding layer, the lower layer having an upper surface serving as a bottom surface of the groove.

Assignees

• Nippon Telegraph & Telephone

Inventors

• Ishikawa Hiroshi
• Shikama Kota
• Kawajiri Yuko
• Aratake Atsushi

Classifications

• G02B2006/12147

  Coupler · CPC title

• G02B6/34

  utilising prism or grating {(G02B6/293 takes precedence)} · CPC title

• G02B6/02209

  Mounting means, e.g. adhesives, casings (G02B6/02171 and G02B6/02195 take precedence) · CPC title

• G02B6/124 Primary

  Geodesic lenses or integrated gratings · CPC title

• G02B6/021

  characterised by the core or cladding or coating, e.g. materials, radial refractive index profiles, cladding shape · CPC title