Edge construction on optical devices

• US 10,539,815 B2
• Filed: 11/07/2017
• Issued: 01/21/2020
• Est. Priority Date: 09/22/2016
• Status: Active Grant

• Current Assignee: Mellanox Technologies, Inc. (NVIDIA Corporation)
• Original Assignee: Mellanox Technologies Silicon Photonics Inc. (NVIDIA Corporation)
• Inventors: Qian, Wei, Sharma, Monish
• Primary Examiner(s): Alanko, Anita K
• Application Number:
  US15/806,272
• Publication Number:
  US 20180081207A1
• Time in Patent Office: 805 Days
• CPC Class Codes: G02B 2006/12173 Masking
• CPC Class Codes: G02B 6/1223 high refractive index type, i.e. high-contrast waveguides
• CPC Class Codes: G02B 6/136 by etching
• CPC Class Codes: G02B 6/241 Light guide terminations
• CPC Class Codes: G02B 6/29314 by moving or modifying the diffractive element, e.g. deforming
• CPC Class Codes: G02B 6/30 for use between fibre and thin-film device
• CPC Class Codes: G02B 6/3636 the mechanical coupling means being grooves G02B6/3652 takes precedence
• CPC Class Codes: G02B 6/3688 using laser ablation
• CPC Class Codes: G02B 6/4207 with optical elements reducing the sensitivity to optical feedback anti-reflection devices specially adapted for lasers, see H01S3/0064
• CPC Class Codes: G02B 6/4224 using visual alignment markings, e.g. index methods
• CPC Class Codes: G02B 6/4231 with intermediate elements, e.g. rods and balls, between the elements
• CPC Class Codes: G02F 1/0136 for the control of polarisation, e.g. state of polarisation [SOP] control, polarisation scrambling, TE-TM mode conversion or separation G02F1/0353 takes precedence
• CPC Class Codes: G02F 1/125 in an optical waveguide structure

Abstract

A method of forming an optical device includes forming a waveguide mask on a device precursor. The device precursor includes a waveguide positioned on a base. The method also includes forming a facet mask on the device precursor such that at least a portion of the waveguide mask is between the facet mask and the base. The method also includes removing a portion of the base while the facet mask protects a facet of the waveguide. The portion of the base that is removed can be removed such that a recess is defined in the base and/or a shelf is defined on the device precursor. A light source such as an optical fiber or laser can be received in the recess and/or positioned over the shelf such that the light source is optically aligned with the facet of the waveguide.

Claims

1. A method of forming an optical device, comprising:

forming a waveguide mask on a device precursor,

the device precursor including a waveguide positioned on a base;

forming a facet mask on the device precursor such that at least a portion of the waveguide mask is between the facet mask and the base;

removing a portion of the base while the facet mask protects a facet of the waveguide;

removing a first portion of the facet mask from over the waveguide after forming the facet mask and before forming the recess;

forming a recess in the base while a protective portion of the facet mask is over a facet of the waveguide, the protective portion of the facet mask also being over a facet shelf that extends from a side of the recess; and

aligning a light source with the facet such that the light source and the waveguide can exchange light signals.

2. The method of claim 1, wherein the light source is a laser.

3. The method of claim 1, wherein aligning the light source with the facet includes positioning the light source on one or more stops that extend upward from a shelf included on the base.

4. The method of claim 1, further comprising forming at least a portion of each one of the one or more stops on the device precursor after forming the facet mask.

5. The method of claim 1, further comprising:

placing the light source in the recess such that a facet of the light source is aligned with the facet of the waveguide.

6. The method of claim 1, further comprising:

removing a portion of the device precursor after forming the waveguide mask and before forming the facet mask, the portion of the device precursor being removed so as to define the facet on the device precursor.

7. The method of claim 1, wherein the protective portion of the facet mask has a thickness less than 0.5 μ

m where the thickness is measured in a direction perpendicular to a surface of the waveguide mask.

8. The method of claim 1, wherein a thickness of the protective portion of the facet mask over the facet is less than 0.5 μ

m, where the thickness is measured in a direction perpendicular to the facet.

9. The method of claim 1, wherein the thickness of the protective portion of the facet mask over the facet varies across the facet and a maximum of the thickness is less than 0.5 μ

m.

10. The method of claim 9, further comprising:

removing the protective portion of the facet mask before aligning the light source with the facet.

11. The method of claim 1, wherein after removing the portion of the base, the facet is above the facet shelf and the facet shelf extends outward from the facet such that the waveguide and the facet shelf are located on opposing sides of the facet.

12. The method of claim 11, wherein the facet shelf has a width less than 0.5 μ

m.

13. The method of claim 1, wherein after removing the portion of the base, the facet is flush with a portion of the base.

14. The method of claim 1, wherein after removing the portion of the base a second portion of the base that remains on the device precursor undercuts the waveguide.

15. The method of claim 1, further comprising:

removing from the device precursor the protective portion of the facet mask after the portion of the base is removed.

16. The method of claim 15, wherein the facet is above the facet shelf and the facet shelf extends outward from the facet such that the waveguide and the facet shelf are located on opposing sides of the facet, and

the protective portion of the facet mask is removed such that a thickness of the facet shelf is reduced,

the thickness of the facet shelf being measured in a direction that is perpendicular to a plane that includes the facet.

17. A method of forming an optical device, comprising:

forming a waveguide mask on a device precursor,

the device precursor including a waveguide positioned on a base;

forming a facet mask on the device precursor such that at least a portion of the waveguide mask is between the facet mask and the base;

removing a portion of the base while the facet mask protects a facet of the waveguide, the portion of the base being removed such that after removing the portion of the base the facet is above a facet shelf that extends outward from the facet with the waveguide and the facet shelf being on opposing sides of the facet, the facet shelf having a width less than 0.5 μ

m; and

aligning a light source with the facet such that the light source and the waveguide can exchange light signals.

19. The method of claim 17, wherein removing the portion of the base forms a recess in the base and further comprising:

placing a laser in the recess such that a facet of the laser is aligned with the facet of the waveguide.

20. The method of claim 17, further comprising:

removing from the device precursor the facet mask after the portion of the base is removed, the facet mask being removed such that a thickness of the facet shelf is reduced, the thickness of the facet shelf being measured in a direction that is perpendicular to a plane that includes the facet.

21. The method of claim 17, wherein a second portion of the base that remains on the device precursor after removing the portion of the base undercuts the waveguide.

18. A method of forming an optical device, comprising:

forming a waveguide mask on a device precursor,

the device precursor including a waveguide positioned on a base;

forming a facet mask on the device precursor such that at least a portion of the waveguide mask is between the facet mask and the base;

removing a portion of the base while the facet mask protects a facet of the waveguide, the portion of the base being removed such that after removing the portion of the base the facet is above a facet shelf that extends outward from the facet with the waveguide and the facet shelf being on opposing sides of the facet;

removing from the device precursor a protective portion of the facet mask, the protective portion of the facet mask being a portion of the facet mask that remains on the device precursor after the portion of the base is removed, the protective portion of the facet mask being removed such that a thickness of the facet shelf is reduced, the thickness of the facet shelf being measured in a direction that is perpendicular to the facet; and

aligning a light source with the facet such that the light source and the waveguide can exchange light signals.

22. The method of claim 18, wherein a second portion of the base that remains on the device precursor after removing the portion of the base undercuts the waveguide.

23. A method of forming an optical device, comprising:

forming a waveguide mask on a device precursor,

the device precursor including a waveguide positioned on a base;

forming a facet mask on the device precursor such that at least a portion of the waveguide mask is between the facet mask and the base;

removing a portion of the base while the facet mask protects a facet of the waveguide, a second portion of the base that remaining on the device precursor undercuts the waveguide after removing the portion of the base;

forming a recess in the base while a protective portion of the facet mask is over a facet of the waveguide, the protective portion of the facet mask also being over a facet shelf that extends from a side of the recess; and

aligning a light source with the facet such that the light source and the waveguide can exchange light signals.