Passive alignment of optical components using optical fiber stubs

Patent metadata

Field	Value
Publication number	US-9575267-B1
Application number	US-201514930857-A
Country	US
Kind code	B1
Filing date	Nov 3, 2015
Priority date	Nov 3, 2015
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

Embodiments herein include an optical system that passively aligns an optical component (e.g., a fiber array connector, lens array, lens body, etc.) with a semiconductor substrate using trenches that mate with optical fiber stubs. In one embodiment, the trenches are etched into the semiconductor substrate which provides support to optical devices (e.g., lasers, lens arrays, photodetectors, etc.) that transmit optical signals to, or receive optical signals from, the optical component. An underside of the optical component is etched to include at least two grooves (e.g., V-grooves) for receiving optical fiber stubs. In one embodiment, the optical fiber stubs are a portion of optical fiber that includes the core and cladding but not the insulative jacket. Once the fiber stubs are attached to the grooves, the fiber stubs are disposed into the trenches in the semiconductor substrate thereby passively aligning the optical component to the optical device on the substrate.

First claim

We claim:

1. An optical system, comprising:
a semiconductor substrate comprising a plurality of trenches;
an optical component comprising at least one lens and a plurality of grooves, wherein the plurality of grooves are formed on a same surface of the optical component; and
a plurality of optical fiber stubs, wherein each of the optical fiber stubs is at least partially disposed in one of the plurality of grooves and one of the plurality of trenches, whereby the optical fiber stubs establish optical alignment between the at least one lens and an optical device disposed on the semiconductor substrate,
wherein a first trench of the plurality of trenches includes a width that is less than a diameter of the optical fiber stubs and a second trench of the plurality of trenches includes a width that is greater than a diameter of the optical fiber stubs, and wherein a depth of the first trench is greater than a depth of the second trench.

2. The optical system of claim 1 , wherein the optical fiber stubs are not coupled to any light source in the optical system.

3. The optical system of claim 1 , wherein each of the optical fiber stubs includes a core and a cladding, but not a jacket, of an optical fiber cable.

4. The optical system of claim 1 , wherein the plurality of grooves are formed along a same plane of the optical component, wherein each of the plurality of grooves is one of a V-groove and a U-groove, and wherein each of the plurality of trenches has a square cross section.

5. The optical system of claim 1 , wherein the depth of the first trench ensures a first fiber stub deposited in the first trench does not contact a bottom surface of the first trench, and wherein the depth of the second trench ensures a second fiber stub deposited in the second trench does contact a bottom surface of the second trench.

6. The optical system of claim 1 , wherein the semiconductor substrate is a laser module and the optical device is a laser configure to transmit a continuous wave to the at least one lens, and wherein the optical component is a silicon lens body.

7. The optical system of claim 1 , wherein the semiconductor substrate is an interposer including a plurality of through vias for electrically connecting a top surface of the interposer comprising the plurality of trenches to an opposite, bottom surface of the interposer, and wherein the optical component is a fiber array connector.

8. The optical system of claim 1 , wherein the semiconductor substrate is a photonic chip and the optical device is at least one waveguide for transmitting light to, or receiving light from, the at least one lens, and wherein the optical component comprises a lens array optically aligned to the photonic chip.

9. A method of aligning an optical component comprising at least one lens and a plurality of grooves each containing an optical fiber stub, the method comprising:
etching a plurality of trenches into a semiconductor substrate, wherein a first trench of the plurality of trenches includes a width that is less than a diameter of the optical fiber stubs and a second trench of the plurality of trenches includes a width that is greater than a diameter of the optical fiber stubs, wherein a depth of the first trench is greater than a depth of the second trench; and
disposing, at least partially, each of the optical fiber stubs into a respective one of the plurality of trenches thereby passively aligning the at least one lens to an optical device disposed on the semiconductor substrate in at least one direction.

10. The method of claim 9 , wherein each of the optical fiber stubs includes a core and a cladding, but not a jacket, of an optical fiber cable.

11. The method of claim 9 , further comprising:
attaching the optical fiber stubs into the plurality of grooves before disposing the optical fiber stubs into the plurality of trenches.

12. The method of claim 9 , wherein the depth of the first trench ensures a first fiber stub deposited in the first trench does not contact a bottom surface of the first trench, and wherein the depth of the second trench ensures a second fiber stub deposited in the second trench does contact a bottom surface of the second trench.

13. The method of claim 9 , further comprising:
etching in parallel respective trenches in multiple semiconductor substrates in a semiconductor wafer.

14. An optical component, comprising:
a body comprising a plurality of grooves formed in a same surface of the body;
at least one lens; and
a plurality of optical fiber stubs, wherein each of the optical fiber stubs is at least partially disposed in one of the plurality of grooves, whereby the optical fiber stubs establish optical alignment between the at least one lens and an optical device external to the optical component,
wherein the optical fiber stubs are not configured to transmit any optical signal and
wherein a first grooves of the plurality of grooves includes a width that is less than a diameter of the plurality of optical fiber stubs and a second groove of the plurality of grooves includes a width that is greater than a diameter of the plurality of optical fiber stubs, and wherein a depth of the first groove is greater than a depth of the second groove.

15. The optical component of claim 14 , wherein each of the optical fiber stubs includes a core and a cladding, but not a jacket, of an optical fiber cable.

16. The optical component of claim 14 , wherein the plurality of grooves are formed along a same plane of the body.

17. The optical component of claim 14 , further comprising a plurality of lenses arranged in an array.

18. The optical component of claim 14 , wherein the body and the lens are formed from a semiconductor material.

Assignees

• Cisco Tech Inc

Inventors

• Shastri Kalpendu
• Pathak Soham
• Yelamarty Rao V
• Dubey Neeraj Kumar

Classifications

• G02B6/421

  the intermediate optical component consisting of a short length of fibre, e.g. fibre stub · CPC title

• G02B6/4292 Primary

  the light guide being disconnectable from the opto-electronic element, e.g. mutually self aligning arrangements · CPC title

• G02B6/4243 Primary

  Mounting of the optical light guide into a groove (mounting optical light guides into a groove in general G02B6/3636) · CPC title

• G02B6/425

  Optical features (semiconductor laser arrays H01S5/40; hybrid LED arrays H10W90/00) · CPC title

• G02B6/423

  using guiding surfaces for the alignment · CPC title