Method for aligning electro-optic device with optical fiber array with optical grating couplers

Patent metadata

Field	Value
Publication number	US-9766417-B2
Application number	US-201615350901-A
Country	US
Kind code	B2
Filing date	Nov 14, 2016
Priority date	Jun 30, 2015
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A method is for aligning an electro-optic device. The method may include initially positioning an optical fiber array adjacent to optical grating couplers, and actively aligning the optical fiber array relative to the optical grating couplers in a yaw direction and a roll direction to determine a yaw and roll alignment at a first operating wavelength. The method may include actively aligning the optical fiber array relative to optical grating couplers in an x direction and a y direction to determine a first x and y alignment at the first operating wavelength, determining a second operating wavelength, and actively aligning the optical fiber array again relative to the optical grating couplers in the x direction and y direction to determine a second x and y alignment at the second operating wavelength.

First claim

That which is claimed is:

1. A method for aligning an electro-optic device comprising a photonic chip having a plurality of optical grating couplers at a surface of the photonic chip, and an optical fiber array comprising a plurality of single mode optical fibers and a body retaining proximal ends of the plurality of single mode optical fibers in side-by-side relation, the method comprising: initially positioning the optical fiber array adjacent the plurality of optical grating couplers; actively aligning the optical fiber array relative to the plurality of optical grating couplers in a yaw direction and a roll direction to determine a yaw and roll alignment at a first operating wavelength, the actively aligning comprising coupling a plurality of photodiodes respectively to proximal ends of the plurality of single mode optical fibers, and determining an optimum a yaw and roll position based upon each single mode optical fiber having a same threshold power; actively aligning the optical fiber array relative to the plurality of optical grating couplers in an x direction and a y direction to determine a first x and y alignment at the first operating wavelength; determining a second operating wavelength by determining a peak power transmission value and associated peak power wavelength based upon a spectral sweep, the peak power wavelength defining the second operation wavelength; and actively aligning the optical fiber array again relative to the plurality of optical grating couplers in the x direction and y direction to determine a second x and y alignment at the second operating wavelength.

2. The method of claim 1 wherein actively aligning the optical fiber array relative to the plurality of optical grating couplers in the x direction and the y direction comprises launching an optical signal from a single optical grating coupler from the plurality of the optical grating couplers to a single photodiode.

3. The method of claim 2 wherein actively aligning the optical fiber array relative to the plurality of optical grating couplers in the x direction and the y direction comprises using an optical splitter coupled between the distal end of a single mode optical fiber and the single photodiode.

4. The method of claim 1 wherein actively aligning the optical fiber array relative to the plurality of optical grating couplers in the x direction and the y direction comprises launching an optical signal from an optical source to a single optical grating coupler from the plurality of optical grating couplers.

5. The method of claim 1 further comprising geometrically aligning the optical fiber array in a pitch direction.

6. The method of claim 1 wherein determining the second operating wavelength comprises determining an optimum wavelength based upon a threshold power through the plurality of optical grating couplers and the optical fiber array.

7. The method of claim 1 further comprising activating an optical source coupled to the optical fiber array before the actively aligning of the optical fiber array relative to the plurality of optical grating couplers in the yaw direction and the roll direction.

8. The method of claim 1 wherein at least some of the adjacent optical fibers of the plurality of optical fibers have alignment mismatch.

9. The method of claim 1 further comprising mounting the optical fiber array onto a 5-axis probe support device.

10. A method for aligning an electro-optic device comprising a photonic chip having a plurality of optical grating couplers at a surface of the photonic chip, and an optical fiber array comprising a plurality of single mode optical fibers and a body retaining proximal ends of the plurality of optical fibers in side-by-side relation, the method comprising: actively aligning the optical fiber array relative to the plurality of optical grating couplers in a yaw direction and a roll direction to determine a yaw and roll alignment at a first operating wavelength, the actively aligning comprising coupling a plurality of photodiodes respectively to proximal ends of the plurality of single mode optical fibers, and determining a desired yaw and roll position based upon each optical fiber having a same threshold power; actively aligning the optical fiber array relative to the plurality of optical grating couplers in an x direction and a y direction to determine a first x and y alignment at the first operating wavelength; determining a second operating wavelength by determining a peak power transmission value and associated peak power wavelength based upon a spectral sweep, the peak power wavelength defining the second operation wavelength; and actively aligning the optical fiber array again relative to the plurality of optical grating couplers in the x direction and y direction to determine a second x and y alignment at the second operating wavelength.

11. The method of claim 10 wherein actively aligning the optical fiber array relative to the plurality of optical grating couplers in the x direction and the y direction comprises launching an optical signal from a single optical grating coupler from the plurality of the optical grating couplers to a single photodiode.

12. The method of claim 11 wherein actively aligning the optical fiber array relative to the plurality of optical grating couplers in the x direction and the y direction comprises using an optical splitter coupled between the distal end of an optical fiber and the single photodiode.

13. The method of claim 10 wherein actively aligning the optical fiber array relative to the plurality of optical grating couplers in the x direction and the y direction comprises launching an optical signal from an optical source to a single optical grating coupler from the plurality of optical grating couplers.

14. The method of claim 10 further comprising geometrically aligning the optical fiber array in a pitch direction.

15. The method of claim 10 wherein determining the second operating wavelength comprises determining an optimum wavelength based upon a threshold power through the plurality of optical grating couplers and the optical fiber array.

16. The method of claim 10 further comprising activating an optical source coupled to the optical fiber array before the actively aligning of the optical fiber array relative to the plurality of optical grating couplers in the yaw direction and the roll direction.

17. The method of claim 10 wherein at least some of the adjacent optical fibers of the plurality of optical fibers have alignment mismatch.

18. The method of claim 10 further comprising mounting the optical fiber array onto a 5-axis probe support device.

19. A method for aligning an electro-optic device comprising a photonic chip having a plurality of optical grating couplers at a surface of the photonic chip, and an optical fiber array comprising a plurality of single mode optical fibers and a body retaining proximal ends of the plurality of optical fibers in side-by-side relation, the method comprising:
actively aligning the optical fiber array relative to the plurality of optical grating couplers in a yaw direction and a roll direction to determine a yaw and roll alignment at a first operating wavelength, the actively aligning comprising coupling a plurality of photodiodes respectively to proximal ends of the plurality of single mode optical fibers, and determining a desired yaw and roll position based upon each optical fiber having a same threshold power;
actively aligning the optical fiber array relative to the plurality of optical grating couplers in an x direction and a

Assignees

• St Microelectronics Crolles 2 Sas

Inventors

• Lemaitre Patrick
• Carpentier Jean-Francois

Classifications

• G02B6/425

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

• G02B6/34

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

• G02B6/124

  Geodesic lenses or integrated gratings · CPC title

• G02B6/4225 Primary

  by a direct measurement of the degree of coupling, e.g. the amount of light power coupled to the fibre or the opto-electronic element · CPC title

• G02B6/4227

  Active alignment methods, e.g. procedures and algorithms · CPC title