Wafer integration of micro-optics

• US 6,909,554 B2
• Filed: 01/27/2003
• Issued: 06/21/2005
• Est. Priority Date: 12/27/2000
• Status: Expired due to Term

• Current Assignee: II-VI Delaware, Inc. (Coherent Corp.)
• Original Assignee: Finisar Corporation (II-VI Incorporated)
• Inventors: Liu, Yue, Fritz, Bernard S., Johnson, Klein L., Cox, James A.
• Primary Examiner(s): Ben, Loha
• Application Number:
  US10/351,710
• Publication Number:
  US 20050052751A1
• Time in Patent Office: 876 Days
• Field of Search: 359/626, 359/619, 359/621, 359/455, 359/719, 250/201.8, 250/208.1, 250/214.1, 348/340, 355/40, 355/44, 257/59, 257/232, 257/233, 257/432, 257/290, 257/291, 257/292, 427/162, 427/163.2
• US Class Current: 359/626
• CPC Class Codes: F21Y 2107/10 on concave supports or substrates, e.g. on the inner side of bowl-shaped supports
• CPC Class Codes: F21Y 2107/50 on planar substrates or supports, but arranged in different planes or with differing orientation, e.g. on plate-shaped supports with steps on which light-generating elements are mounted
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 27/0025 for optical correction, e.g. distorsion, aberration
• CPC Class Codes: G02B 3/0012 characterised by the manufacturing method
• CPC Class Codes: G02B 3/0018 Reflow, i.e. characterized by the step of melting microstructures to form curved surfaces, e.g. manufacturing of moulds and surfaces for transfer etching
• CPC Class Codes: G02B 3/0043 Inhomogeneous or irregular arrays, e.g. varying shape, size, height
• CPC Class Codes: G02B 3/005 arranged along a single direction only, e.g. lenticular sheets G02B3/0043 takes precedence
• CPC Class Codes: G02B 6/12002 Three-dimensional structures
• CPC Class Codes: G02B 6/138 by using polymerisation
• CPC Class Codes: G02B 6/4201 Packages, e.g. shape, construction, internal or external details
• CPC Class Codes: G02B 6/4206 Optical features G02B6/4207, G02B6/421 take precedence
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• CPC Class Codes: G02B 6/4249 comprising arrays of active devices and fibres
• CPC Class Codes: G02B 7/04 with mechanism for focusing or varying magnification
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H01L 31/0232 Optical elements or arrangements associated with the device H01L31/0236 takes precedence; for photovoltaic cells H01L31/054; for photovoltaic modules H02S40/20
• CPC Class Codes: H01L 31/02325 the optical elements not being integrated nor being directly associated with the device
• CPC Class Codes: H01L 31/02327 the optical elements being integrated or being directly associated to the device, e.g. back reflectors optical coatings H01L31/0216

Abstract

The present invention provides an optical system that includes an array of opto-electronic devices, an array of micro lenses, and a fore optic. The array of opto-electronic devices lie substantially along a plane, but the fore optic has a non-planar focal field. To compensate for the non-planar focal field of the fore optic, each opto-electronic device has a corresponding micro lens. Each micro lens has a focal length and/or separation distance between it and it respective opto-electronic device, which compensates for the non-planar focal field of the fore optic. The focal lengths of these lenses may differ relative to one another. As a result, light that is provided by the fore optic is reconfigured by the micro lenses having various focal lengths to be substantially focused along the plane of the array of opto-electronic devices. Various arrangements of microlenses, placing lenses on standoffs or posts, forming of optical waveguides, lens fabrication, wafer integration of micro-optics, and optical coupling are noted.

Claims

1. An optical system, comprising:

a plurality of opto-electronic devices situated substantially in a plane;

a fore optic, having an optical axis, situated proximate to said plurality of opto-electronic devices; and

a plurality of micro lenses situated between said plurality of opto-electronic devices and said fore optic; and

wherein;

each micro lens of said plurality of micro lenses is situated on a post.

2. The system of claim 1, wherein:

said fore optic has a non-planar focal field; and

each micro lens has focal length at least partially determined by a dimension of a respective post, to substantially planarize the non-planar focal field of said fore optic.

3. The system of claim 2, wherein each post is situated on an opto-electronic device of said plurality of opto-electronic devices.

4. The system of claim 3, wherein said plurality of opto-electronic devices is a plurality of opto-electronic emitters and/or detectors.

5. The system of claim 4, wherein each opto-electronic emitter is a VCSEL.

6. The system of claim 4, wherein each opto-electronic detector is a RCPD.

7. The system of claim 4, wherein each opto-electronic emitter is an LED.

8. The system of claim 4, wherein each opto-electronic detector is CCD.

9. The system of claim 2, wherein the focal length of each micro lens of said plurality of micro lenses increases with a distance increase away from the optical axis of said fore optic.

10. The system of claim 2, wherein the focal length of each micro lens is set for focus or relaying light between the said fore optic having the non-planar field, and a corresponding opto-electronic device.

11. The system of claim 2, wherein the optical axis of said fore optic is centered along a center axis of said plurality of opto-electronic devices.

12. The system of claim 2, wherein the optical axis of said fore optic is offset from a center axis of said plurality of opto-electronic devices.

13. A method for compensating for a non-planar focal field of a fore optic used in an optical system having a plurality of opto-electronic devices, comprising:

providing a plurality of opto-electronic devices substantially in a plane;

providing a fore optic having an optical axis;

providing a plurality of micro lenses situated on a plurality of posts;

setting the lengths of said plurality of posts to at least partially adjust the focal lengths of the plurality of micro lenses to compensate for the non-planar focal field of the fore optic.

14. The method of claim 13, wherein the plurality of the opto-electronic devices is a plurality of opto-electronic emitters and/or detectors.

15. The method of claim 14, wherein the opto-electronic emitters are VCSELs.

16. The method of claim 14, wherein the opto-electronic detectors are RCPDs.

17. The method of claim 14, wherein the opto-electronic emitters are LEDs.

18. The method of claim 14, wherein the opto-electronic detector are CCDs.

19. The method of claim 14, wherein the opto-electronic detectors are CCDs.

20. The method of claim 13, wherein the focal length of each micro lens of the plurality of micro lenses increases with a distance increase away from the optical axis of the fore optic.

21. The method of claim 13, wherein the focal length of each micro lens is set for each micro lens to focus or relay light between the fore optic having the non-planar focal field, and a corresponding opto-electronic device.

22. The method of claim 13, wherein the optical axis of the fore optic is centered along a center axis of the plurality of opto-electronic devices.

23. The method of claim 13, wherein the optical axis of the fore optic is offset from a center axis of the plurality of opto-electronic devices.

24. An optical system comprising:

an array of opto-electronic devices situated substantially in a plane;

a fore optic having a non-planar focal field, proximate to said array of opto-electronic devices;

an array of micro lenses situated between said fore optic and said array of opto-electronic devices; and

an array of spacers situated between said array of micro lenses and said array of opto-electronic devices; and

wherein;

each spacer provides a separation distance between each micro lens and each opto-electronic device; and

the separation distance at least partially compensates for the non-planar focal field of said fore optic.

25. The system of claim 24, wherein the separation distance of each micro lens tracks the non-planar focal field of said fore optic to substantially planarize the focal field.

26. The system of claim 24, wherein each micro lens has a focal length related to its separation distance.

27. An optical system comprising:

a fore optic having a non-planar focal field;

a plurality of substantially optically transparent posts situated on a first surface of a first substrate;

a plurality of micro lenses situated on said plurality of posts; and

wherein;

focal lengths of said plurality of said micro lenses are at least partially determined by distances of said plurality of posts between the micro lenses and the first surface of said first substrate; and

the focal lengths of said plurality of said micro lenses are such as to compensate the non-planar focal field of said fore optic into a substantially planar focal field.

28. The optical system of claim 27, wherein:

a second surface of said first substrate is substantially planar; and

the focal field of the fore optic is substantially planar at the second surface of said first substrate.

29. The optical system of claim 28, further comprising:

a plurality of opto-electronic devices situated on a first surface of a second substrate; and

wherein the first surface of the second substrate is substantially planar.

30. The optical system of claim 29, wherein the second surface of the first substrate is attached to the first surface of the second substrate.

31. The optical system of claim 29, wherein the second surface of the first substrate is bonded to the first surface of the second substrate.

32. Means for planarizing a focal field, comprising:

means for focusing light having a non-planar focal field; and

means for substantially planarizing the focal field; and

wherein;

said means for substantially planarizing comprises means for focusing in increments;

the focusing in increments has various focal lengths for substantially planarizing the focal field; and

the various focal lengths are at least partially provided by various supports for means for focusing.

33. The means of claim 32, further comprising means for supporting various length supports.

34. The means of claim 33, further comprising means for emitting and/or detecting light proximate to said means for substantially planarizing the focal field.

35. The means of claim 34, wherein said means for supporting various length supports has a substantially planar surface adjacent to said means for emitting and/or detecting light.

36. The means of claim 35, wherein said means for emitting and/or detecting light has a substantially planar surface adjacent to the substantially planar surface of said means for supporting various length supports.