Passive fiber optic butt coupling using a semiconductor etched feature

Patent metadata

Field	Value
Publication number	US-9971096-B2
Application number	US-201615169836-A
Country	US
Kind code	B2
Filing date	Jun 1, 2016
Priority date	Jun 1, 2016
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

Embodiments herein include an optical system that passively aligns a fiber array connector (FAC) to a waveguide in a photonic chip. A substrate of the FAC is machined or etched to include multiple grooves along a common axis or plane to hold optical waveguides, or more specifically, the fibers of the optical cables in the FAC. To align the fibers to the photonic chip, one of the fibers is disposed in an alignment trench which has a width that is substantially the same as the diameter of the fiber. When the fiber registers with the alignment trench, the fiber is aligned with a waveguide disposed at the end of the trench. Because the pitch between the fibers can be precisely controlled, aligning one of the fibers using the alignment trench results in the other fibers becoming passively aligned to respective waveguides in the photonic chip.

First claim

We claim:

1. An optical system comprising:
an optical connector, comprising:
a plurality of grooves formed on a common surface of a substrate,
a plurality of fibers of optical cables disposed in the plurality of grooves; and

a photonic chip, comprising:
a plurality of waveguides,
a bulk trench comprising a first bottom surface and a first sidewall extending from the first bottom surface, wherein at least two of the plurality of fibers are disposed within the bulk trench and aligned to respective ones of the plurality of waveguides,
an alignment trench comprising a second bottom surface and a second sidewall extending from the second bottom surface, wherein only one of the plurality of fibers is disposed in the alignment trench, wherein the one of the plurality of fibers registers with the alignment trench thereby aligning the plurality of fibers to the plurality of waveguides; and
a ridge separating the alignment trench and the bulk trench, wherein a first side of the ridge connects to the first bottom surface and a second side of the ridge connects to the second bottom surface.

2. The optical system of claim 1 , wherein a width of the alignment trench is substantially the same as a diameter of the one of the plurality of fibers that registers with the alignment trench.

3. The optical system of claim 1 , wherein the first and second bottom surfaces are arranged on a common plane.

4. An optical system comprising:
an optical connector, comprising:
a plurality of grooves formed on a common surface of a substrate,
a plurality of fibers of optical cables disposed in the plurality of grooves; and

a photonic chip, comprising:
a plurality of waveguides,
a bulk trench comprising a first bottom surface and a first sidewall extending from the first bottom surface, wherein at least two of the plurality of fibers are disposed within the bulk trench and aligned to respective ones of the plurality of waveguides, and
an alignment trench comprising a second bottom surface and a second sidewall extending from the second bottom surface, wherein only one of the plurality of fibers is disposed in the alignment trench, wherein the one of the plurality of fibers registers with the alignment trench thereby aligning the plurality of fibers to the plurality of waveguides,

wherein a portion of the common surface of the substrate in the optical connector directly contacts a portion of a top surface of the photonic chip, wherein a distance between the top surface and the first bottom surface defines a depth of the bulk trench.

5. The optical system of claim 1 , wherein the optical connector is a fiber array connector.

6. An optical system comprising:
an optical connector, comprising:
a plurality of grooves formed on a common surface of a substrate,
a plurality of fibers of optical cables disposed in the plurality of grooves; and

a photonic chip, comprising:
a plurality of waveguides,
a bulk trench comprising a first bottom surface and a first sidewall extending from the first bottom surface, wherein at least two of the plurality of fibers are disposed within the bulk trench and aligned to respective ones of the plurality of waveguides,
an alignment trench comprising a second bottom surface and a second sidewall extending from the second bottom surface, wherein only one of the plurality of fibers is disposed in the alignment trench, wherein the one of the plurality of fibers registers with the alignment trench thereby aligning the plurality of fibers to the plurality of waveguides, and
an optical component optically coupled to at least one of the plurality of waveguides, wherein the at least one of the plurality of waveguides has a width and height that is less than a micron.

7. The optical system of claim 6 , wherein the photonic chip comprises a silicon on insulator structure.

Assignees

• Cisco Tech Inc

Inventors

• Shastri Kal
• Yelamarty Rao
• Dubey Neeraj
• Piede David
• Li Weizhuo

Classifications

• G02B6/3692

  with surface micromachining involving etching, e.g. wet or dry etching steps (surface micromachining involving subtractive techniques B81C1/00055) · CPC title

• G02B6/3652 Primary

  the additional structures being prepositioning mounting areas, allowing only movement in one dimension, e.g. grooves, trenches or vias in the microbench surface, i.e. self aligning supporting carriers · CPC title

• G02B6/136

  by etching · CPC title

• G02B2006/12097

  Ridge, rib or the like · CPC title

• G02B2006/121

  Channel; buried or the like · CPC title