Method for forming an aligned optical sub-assembly

• US 20050220416A1
• Filed: 04/06/2004
• Published: 10/06/2005
• Est. Priority Date: 04/06/2004
• Status: Active Grant

• Current Assignee: 4Wave, Inc.
• Original Assignee: 4Wave, Inc.
• Inventors: Minnemann, Michael Joseph, Baldwin, David Alan
• Granted Patent: US 7,177,506 B2
• Time in Patent Office: Days
• US Class Current: 385/52
• CPC Class Codes: G02B 6/4204 the coupling comprising intermediate optical elements, e.g. lenses, holograms encapsulated active devices H01S5/02208, H01L33/52
• CPC Class Codes: G02B 6/4215 the intermediate optical elements being wavelength selective optical elements, e.g. variable wavelength optical modules or wavelength lockers G02B6/4246 takes precedence
• CPC Class Codes: G02B 6/4227 Active alignment methods, e.g. procedures and algorithms
• CPC Class Codes: G02B 6/423 using guiding surfaces for the alignment
• CPC Class Codes: G02B 6/4249 comprising arrays of active devices and fibres

Abstract

A bench-joining optical component and a first optical component are aligned on a first optical bench, and then rigidly coupled to the first bench, in order to form a first portion of an optical subassembly. Following completion of the first portion, all components in the first portion are pre-aligned and fixed with respect to each other, moving as a unit. A third optical component is aligned and permanently coupled to a second optical bench, in order to form a second portion of the optical sub-assembly. The first and second portions of optical sub-assembly are combined by positioning an exposed side of the bench joining optical component on the second bench, aligning the bench-joining optical component with the third optical component on the second bench, and permanently securing the bench-joining optical component to the second bench.

Claims

1. A method for aligning optical components in order to form an aligned optical sub-assembly, comprising:

(a) positioning a first optical component with respect to a first optical bench having an upper surface;

(b) positioning a bench-joining optical component relative to the upper surface of the first optical bench;

(c) after steps (a) and (b), providing aligned optical components by moving at least one of the bench-joining optical component and the first optical bench until the first optical component and the bench-joining optical component are optically aligned;

(d) after step (c), and while said aligned components remain in an aligned position, permanently securing at least one of the first and bench-joining optical components to the first optical bench;

(e) permanently securing a third optical component to a second optical bench having an upper surface;

(f) after steps (d) and (e), and after the first and bench-joining optical components are permanently secured to the first optical bench, positioning the bench-joining optical component relative to the upper surface of the second optical bench;

(g) after step (f), providing an aligned optical sub-assembly by moving at least one of the bench-joining optical component and the second optical bench until the bench-joining optical component and the third optical component are optically aligned; and

(h) after step (g), permanently securing the bench-joining optical component to the second optical bench.

2. The method of claim 1 wherein the first optical component is one or more optical fibers.

3. The method of claim 2 where the bench-joining optical component comprises an optical multiplexer and a lens array.

4. The method of claim 1 wherein the third optical component is an array of laser diodes.

5. The method of claim 1 wherein the bench-joining optical component consists of a single optical lens.

6. The method of claim 1, wherein the upper surface of the first optical bench is parallel to the upper surface of the second optical bench after step (h).

7. The method of claim 1, wherein the bench-joining optical component comprises an array of optical lenses.

8. The method of claim 1, wherein the first optical component is permanently secured to the first optical bench in step (a), the bench-joining optical component is permanently secured to the first optical bench in step (d), and the positioning of the bench-joining optical component relative to the upper surface of the first optical bench in step (b) fixes a distance between the first optical component and the bench-joining optical component.

9. The method of claim 1, wherein the first optical component and the bench-joining optical component are permanently secured to the first optical bench in step (d).

10. The method of claim 1, wherein, following step (b), translational movement of the bench-joining optical component relative to the upper surface of the first optical bench is restricted in at least one direction and rotational movement of the bench-joining optical component about at least one axis passing through the bench-joining optical component is restricted.

11. The method of claim 10, wherein the upper surface of the first optical bench has a first plurality of stops formed thereon, and step (b) further comprises positioning the bench-joining optical component on the upper surface of the first optical bench between the first plurality of stops, wherein said first plurality of stops restrict rotation of the bench-joining optical component about an axis perpendicular to the upper surface of the first optical bench.

12. The method of claim 1, wherein, following step (f), translational movement of the bench-joining optical component relative to the upper surface of the second optical bench is restricted in at least one direction, rotational movement of the bench-joining optical component about at least one axis passing through the bench-joining optical component is restricted, and a distance between the third optical component and the bench-joining optical component is fixed.

13. The method of claim 12, wherein the upper surface of the second optical bench has a second plurality of stops formed thereon, and step (f) further comprises positioning the bench-joining optical component on the upper surface of the second optical bench between the second plurality of stops, wherein said second plurality of stops restrict rotation of the bench-joining optical component about an axis perpendicular to the upper surface of the second optical bench.

14. The method of claim 11, wherein the first plurality of stops are formed from a de-formable material that grips the bench-joining optical component when the bench-joining optical component is positioned between the first plurality of stops.

15. The method of claim 14, wherein said de-formable material is a polymer.

16. The method of claim 13, wherein the second plurality of stops are formed from a de-formable material that grips the bench-joining optical component when the bench-joining optical component is positioned between the second plurality of stops.

17. The method of claim 16, wherein said de-formable material is a polymer.

18. The method of claim 11, wherein the first optical bench is formed from silicon, further comprising the step of wet-etching the first plurality of stops into the first optical bench.

19. The method of claim 18, wherein the first plurality of stops comprises raised ridges, and said wet-etching comprises etching a remaining surface of the first optical bench.

20. The method of claim 11, wherein the first optical bench is formed from silicon, further comprising the step of etching the first plurality of stops into the first optical bench by plasma-chemical etching.

21. The method of claim 20, wherein the first plurality of stops comprises raised ridges, and said etching comprises etching a remaining surface of the first optical bench by plasma-chemical etching.

22. The method of claim 11, wherein the first optical bench is formed from silicon, and the first plurality of stops are positioned on the first optical bench using photo-lithography to achieve a positional accuracy of less than 1 μ

m.

23. The method of claim 1, further comprising:

(i) permanently securing a fourth optical component to a third optical bench having an upper surface;

(j) after steps (g) and (i), positioning the bench-joining optical component relative to the upper surface of the third optical bench;

(k) after step (j), moving at least one of the bench-joining optical component or the third optical bench until the bench-joining optical component and the fourth optical component are optically aligned; and

(l) after step (k), permanently securing the bench-joining optical component to the third optical bench.

24. The method of claim 23, further comprising:

(m) permanently securing a fifth optical component to a fourth optical bench having an upper surface;

(n) after steps (g) and (m), positioning the bench-joining optical component relative to the upper surface of the fourth optical bench;

(o) after step (n), moving at least one of the bench-joining optical component or the fourth optical bench until the bench-joining optical component and the fifth optical component are optically aligned; and

(p) after step (o), permanently securing the bench-joining optical component to the fourth optical bench.

25. The method of claim 24, further comprising:

(q) permanently securing a sixth optical component to a fifth optical bench having an upper surface;

(r) after steps (g) and (q), positioning the bench-joining optical component relative to the upper surface of the fifth optical bench;

(s) after step (r), moving at least one of the bench-joining optical component or the fifth optical bench until the bench-joining optical component and the sixth optical component are optically aligned; and

(t) after step (o), permanently securing the bench-joining optical component to the fifth optical bench.