Optical alignment system

• US 6,590,658 B2
• Filed: 02/20/2001
• Issued: 07/08/2003
• Est. Priority Date: 02/20/2001
• Status: Expired due to Term

• Current Assignee: RPX Corporation
• Original Assignee: CyberOptics Corporation (Nordson Corporation)
• Inventors: Garfield, Patrick J., McElreath, John T., Case, Steven K., Skunes, Timothy A., Mowry, Gregory S.
• Primary Examiner(s): Lee, Michael G.
• Assistant Examiner(s): Paik, Steven S.
• Application Number:
  US09/789,317
• Publication Number:
  US 20020113969A1
• Time in Patent Office: 868 Days
• Field of Search: 356/400, 356/401, 356/153, 250/548, 385/49, 385/50, 385/89, 385/14
• US Class Current: 356/401
• CPC Class Codes: G02B 6/255 Splicing of light guides, e.g. by fusion or bonding
• CPC Class Codes: G02B 6/2553 Splicing machines, e.g. optical fibre fusion splicer
• CPC Class Codes: G02B 6/2555 Alignment or adjustment devices for aligning prior to splicing
• CPC Class Codes: G02B 6/3616 Holders, macro size fixtures for mechanically holding or positioning fibres, e.g. on an optical bench supporting carriers of a microbench type G02B6/3648; micromanipulators B25J7/00; cassettes, bobbins G02B6/4439
• CPC Class Codes: G02B 6/362 Vacuum holders for optical elements
• CPC Class Codes: G02B 6/3636 the mechanical coupling means being grooves G02B6/3652 takes precedence
• CPC Class Codes: G02B 6/3652 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 Class Codes: G02B 6/3838 using grooves for light guides
• CPC Class Codes: G02B 6/3873 Connectors using guide surfaces for aligning ferrule ends, e.g. tubes, sleeves, V-grooves, rods, pins, balls
• CPC Class Codes: G02B 6/4221 involving a visual detection of the position of the elements, e.g. by using a microscope or a camera
• CPC Class Codes: G02B 6/4224 using visual alignment markings, e.g. index methods
• CPC Class Codes: G02B 6/4225 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 Class Codes: G02B 6/4226 Positioning means for moving the elements into alignment, e.g. alignment screws, deformation of the mount
• CPC Class Codes: G02B 6/4227 Active alignment methods, e.g. procedures and algorithms
• CPC Class Codes: G02B 6/4228 Passive alignment, i.e. without a detection of the degree of coupling or the position of the elements G02B6/4234 takes precedence
• CPC Class Codes: G02B 6/4231 with intermediate elements, e.g. rods and balls, between the elements
• CPC Class Codes: G02B 6/4232 using the surface tension of fluid solder to align the elements, e.g. solder bump techniques flip-chip mounting techniques in assembly of semiconductor devices H01L24/81
• CPC Class Codes: G02B 6/4236 Fixing or mounting methods of the aligned elements
• CPC Class Codes: G02B 6/4239 Adhesive bonding; Encapsulation with polymer material

Abstract

An optical alignment system is provided for aligning an optical module of the type which is suitable for use in an optical device. The system includes a reference base having a registration feature that aligns with a registration feature of the optical module. An optical sensor senses an optical characteristic of the optical element and optical element manipulator moves the optical element relative to the registration features of the optical module. A controller operates the optical element manipulator.

Claims

1. An apparatus for aligning an optical component in an optical module, comprising:

a reference base having a registration feature configured to align with a registration feature of the optical module;

a sensor configured to respond to an optical characteristic of the optical element, the optical characteristic varying with at least one degree of freedom relative to the registration feature of the optical module, and responsively provide a sensor output;

an optical component manipulator configured to provide relative movement between the optical component and the registration features of the optical module; and

wherein the registration features provide substantially kinematic coupling between the reference base and optical module.

2. The apparatus of claim 1 including a controller configured to operate the optical component manipulator.

3. The apparatus of claim 2 wherein the controller operates the optical component manipulator in response to the sensor output.

4. The apparatus of claim 3 wherein the controller actuates the optical component manipulator to align the optical component with a reference.

5. The apparatus of claim 4 wherein the reference is defined with respect to the reference base registration feature.

6. The apparatus of claim 2 wherein the controller is manually operated.

7. The apparatus of claim 1 wherein the optical module includes a relative reference mount which carries the registration feature and the controller is configured to actuate a bonding mechanism to bond the optical component to the relative reference mount.

8. The apparatus of claim 7 wherein the bonding mechanism comprises a heater element configured to melt solder.

9. The apparatus of claim 8 wherein the heater element is carried on the relative reference mount.

10. The apparatus of claim 7 wherein the bonding mechanism comprises a radiation source configured to cure an adhesive material.

11. The apparatus of claim 1 wherein the optical module includes a relative reference mount and the apparatus includes an optical component loading arm configured to place the optical component proximate with the relative reference mount.

12. The apparatus of claim 11 wherein the controller controls operation of the optical component loading arm.

13. The apparatus of claim 1 wherein the optical component manipulator includes a vacuum head configured to selectively attach to the optical component.

14. The apparatus of claim 1 wherein the registration features comprise respective protrusion and depression.

15. The apparatus of claim 1 wherein the sensor is configured to sense light which has interacted with or has been generated by the optical component.

16. The apparatus of claim 15 wherein the sensor provides a fixed reference for aligning a plurality of optical components with respect to the registration feature of the reference base.

17. The apparatus of claim 15 wherein the sensor comprises a reference optical component.

18. The apparatus of claim 1 wherein the sensor comprises electrical circuitry coupled to an electrical output from the optical component, the output related to light received by the optical component.

19. The apparatus of claim 1 including an initial alignment sensor configured to sense initial alignment of the optical component and wherein the sensor provides a fine alignment.

20. The apparatus of claim 19 wherein the initial alignment sensor comprises a camera.

21. The apparatus of claim 20 wherein the initial alignment sensor comprises a plurality of cameras.

22. A method for prealigning an optical module having an optical component and a relative reference mount comprising:

aligning the relative reference mount with registration features of a reference base;

positioning the optical component proximate the relative reference mount;

aligning the optical component with an optical component reference;

coupling the optical component to the relative reference mount when the optical component is aligned with the optical reference to thereby fix the position of the optical component relative to registration features of the relative reference mount to thereby form the optical module;

removing the optical module from the reference base; and

wherein aligning the relative reference mount comprises kinematically coupling the relative reference mount to the reference base.

23. The method of claim 22 wherein coupling the optical component to the relative reference mount includes activating a heater to heat solder.

24. The method of claim 23 wherein the solder fills a gap between the optical component and the relative reference mount.

25. The method of claim 23 wherein activating a heater includes injecting electrical current through an electrical contact on the relative reference mount.

26. The method of claim 22 wherein aligning the optical component with an optical component reference includes observing light that has passed through or been generated by the optical component and the optical component reference and responsively positioning the optical component.

27. The method of claim 22 wherein aligning the optical component includes sensing an electrical output from the optical component generated in response to light received by the optical component.

28. The method of claim 22 wherein placing the optical component proximate the relative reference mount includes observing position of the optical component using at least one camera.

29. The method of claim 22 including loading the optical component in a holder prior to aligning the optical component with the optical component reference.

30. The method of claim 29 including flipping the holder.

31. The method of claim 22 wherein aligning the optical component comprises scanning the optical component through a search pattern relative to the optical component reference.

32. The method of claim 22 wherein the optical component reference is defined relative to the registration features of the reference base.

33. An apparatus for aligning an optical component in an optical module, comprising:

a reference base having a registration feature configured to align with a registration feature of the optical module;

a sensor configured to respond to an optical characteristic of the optical element, the optical characteristic varying with at least one degree of freedom relative to the registration feature of the optical module, and responsively provide a sensor output;

an optical component manipulator configured to provide relative movement between the optical component and the registration features of the optical module;

wherein the registration features comprise protrusion and depression.

34. The apparatus of claim 33 including a controller configured to operate the optical component manipulator.

35. The apparatus of claim 34 wherein the controller operates the optical component manipulator in response to the sensor output.

36. The apparatus of claim 35 wherein the controller actuates the optical component manipulator to align the optical component with a reference.

37. The apparatus of claim 36 wherein the reference is defined with respect to the reference base registration feature.

38. The apparatus of claim 35 wherein the controller is manually operated.

39. The apparatus of claim 33 wherein the optical module includes a relative reference mount which carries the registration feature and the controller is configured to actuate a bonding mechanism to bond the optical component to the relative reference mount.

40. The apparatus of claim 33 wherein the optical module includes a relative reference mount and the apparatus includes an optical component loading arm configured to place the optical component proximate with the relative reference mount.

41. The apparatus of claim 33 wherein the sensor is configured to sense light which has interacted with or has been generated by the optical component.

42. The apparatus of claim 33 including an initial alignment sensor configured to sense initial alignment of the optical component and wherein the sensor provides a fine alignment.

43. A method for prealigning an optical module having an optical component and a relative reference mount comprising:

aligning the relative reference mount with registration features of a reference base;

positioning the optical component proximate the relative reference mount;

aligning the optical component with an optical component reference;

coupling the optical component to the relative reference mount when the optical component is aligned with the optical reference to thereby fix the position of the optical component relative to registration features of the relative reference mount to thereby form the optical module;

removing the optical module from the reference base; and

wherein coupling the optical component to the relative reference mount includes activating a heater to heat solder.

44. A method for prealigning an optical module having an optical component and a relative reference mount comprising:

aligning the relative reference mount with registration features of a reference base;

positioning the optical component proximate the relative reference mount;

aligning the optical component with an optical component reference;

coupling the optical component to the relative reference mount when the optical component is aligned with the optical reference to thereby fix the position of the optical component relative to registration features of the relative reference mount to thereby form the optical module;

removing the optical module from the reference base;

loading the optical component in a holder prior to aligning the optical component with the optical component reference; and

flipping the holder.

45. An apparatus for aligning an optical component in an optical module, comprising:

a reference base having a registration feature configured to align with a registration feature of the optical module;

a sensor configured to respond to an optical characteristic of the optical element, the optical characteristic varying with at least one degree of freedom relative to the registration feature of the optical module, and responsively provide a sensor output;

an optical component manipulator configured to provide relative movement between the optical component and the registration features of the optical module; and

wherein the optical component manipulator includes a vacuum head configured to selectively attach to the optical component.