Optical illuminator

• US 8,675,706 B2
• Filed: 07/05/2012
• Issued: 03/18/2014
• Est. Priority Date: 12/24/2011
• Status: Active Grant

• Current Assignee: Ams-Osram International GmbH (Ams-Osram AG)
• Original Assignee: Princeton Optronics Inc (Ams-Osram AG)
• Inventors: Seurin, Jean F, Ghosh, Chuni L, Wang, Qing, Watkins, Laurence
• Primary Examiner(s): Stultz, Jessica
• Assistant Examiner(s): GOLUB-MILLER, MARCIA A
• Application Number:
  US13/541,906
• Publication Number:
  US 20130163626A1
• Time in Patent Office: 621 Days
• Field of Search: 372/50.124, 372/87
• US Class Current: 372/50.124
• CPC Class Codes: F21L 4/02 characterised by the provision of two or more light sources
• CPC Class Codes: F21V 29/56 using liquid coolants F21V29/51 takes precedence
• CPC Class Codes: F21V 29/65 the gas flowing in a closed circuit
• CPC Class Codes: F21V 29/67 characterised by the arrangement of fans
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/02325 Mechanically integrated components on mount members or optical micro-benches
• CPC Class Codes: H01S 5/02345 Wire-bonding
• CPC Class Codes: H01S 5/0237 by soldering
• CPC Class Codes: H01S 5/02469 Passive cooling, e.g. where heat is removed by the housing as a whole or by a heat pipe without any active cooling element like a TEC
• CPC Class Codes: H01S 5/02476 Heat spreaders, i.e. improving heat flow between laser chip and heat dissipating elements
• CPC Class Codes: H01S 5/141 using a wavelength selective device, e.g. a grating or etalon H01S5/146 takes precedence
• CPC Class Codes: H01S 5/18305 with emission through the substrate, i.e. bottom emission
• CPC Class Codes: H01S 5/18308 having a special structure for lateral current or light confinement
• CPC Class Codes: H01S 5/4018 Lasers electrically in series
• CPC Class Codes: H01S 5/423 having a vertical cavity

Abstract

Illuminator module comprising VCSEL arrays with planar electrical contacts, readily adaptable for surface mounting, is provided. Monolithic VCSEL arrays are configured in array patterns on two and three-dimensional surfaces. Illuminator modules are easily expandable by increasing the array size or by modularly arranging more arrays with or without a transparent substrate. Different shapes of illuminator modules may be configured by tiling array modules monolithically on a common substrate, or by tiling small modules. The surface mountable illuminator modules are easily assembled on a thermally conductive surface that may be air or liquid cooled for efficient heat dissipation. Array modules may be integrated with other electronic circuits such as current drivers, sensors, controllers, processors, etc. on a common platform, for example, a single or multiple layer printed circuit boards (PCB) to assemble illumination systems for different applications including a gesture recognition apparatus and a battery operated portable illuminator devices.

Claims

1. An illuminator module comprising:

a) at least one array comprising a plurality of Vertical Cavity Surface Emitting Lasers (VCSELs), the VCSELs emitting light collectively in a direction perpendicular to an emission surface of the array that comprises a plurality of emission windows in a first contiguous metallized layer located on the emission surface of the array, each emission window being substantially aligned with a respective VCSEL of said array, wherein said first metallized layer in electrical contact with the VCSELs provides a common first electrical contact, and a second metallized layer in electrical contact with the VCSELs and located on an opposing non-emission surface provides a common second electrical contact, respectively, to the at least one array;

b) a trench located on the non-emission surface of the array, said trench electrically isolating the second electrical contact of the array from an electrical contact region located on the non-emission surface; and

c) an electrically conducting path connecting the first electrical contact located on the emission surface to the electrical contact region located on the non-emission surface, such that the first electrical contact and the second electric contact are coplanar and accessible on the non-emission surface for surface mounting.

2. The illuminator module as in claim 1, wherein the electrically conducting path to the electrical contact region on the non-emission surface is effected through a gold bump having a thickness substantially equal to the thickness of the at least one array.

3. The illuminator module as in claim 1, wherein the VCSELs are configured in top or bottom emission mode.

4. The illuminator module as in claim 1 further comprising a substrate that physically supports the at least one array, wherein the substrate comprises a thickness that facilitates efficient heat dissipation from the at least one array.

5. The illuminator module as in claim 1 further comprising a substrate that physically supports the at least one array, wherein the substrate comprises a thickness that substantially reduces re-absorption of the light emitted from the at least one array.

6. The illuminator module as in claim 1 further comprising a thermally conducting submount, the illuminator module being surface mounted on the submount.

7. The illuminator module as in claim 1 further comprising an encapsulation disposed over the emission surface of the at least one array, wherein the encapsulation comprises an optical device selected from the group consisting of a transparent window, a lens, a lens array and a diffuser.

8. The illuminator module as in claim 1, wherein the illuminator module is surface mounted on a printed circuit board comprising one or more electronic circuits that are electrically connected to the at least one array.

9. The illuminator module as in claim 8, wherein the one or more electronic circuit are chosen from the group consisting of current drivers, image sensors, cameras, controllers, and processors.

10. The illuminator module as in claim 8, wherein the illuminator module is configured including a current driver, a camera, an image sensor, a controller and a processor for constructing a motion sensing or a gesture recognition device.

11. The illuminator module as in claim 8, wherein the printed circuit board comprises metalization layers on multiple levels that connect to one or more electronic circuits palced at different ones of said multiple levels according to their current carrying requirement to facilitate connecting the at least one array module to the one or more electronic circuits palced at different ones of said multiple levels.

12. The illuminator module as in claim 8 further including an encapsulation disposed over the at least one array and the one or more electronic circuits, the encapsulation providing an optical device selected from the group consisting of a transparent window, a lens, a lens array and a diffuser.

13. The illuminator module as in claim 1 further including one or more additional arrays, the additional arrays being electrically connected to the at least one array.

14. The illuminator module as in claim 1, further comprising an array of microlenses that are substantially aligned with the corresponding VCSELs in the array module, and wherein the array of microlenses is constructed integral to the at least one array.

15. An illuminator module comprising:

a) at least one array comprising a plurality of Vertical Cavity Surface Emitting Lasers (VCSELs), the VCSELs emitting light collectively in a direction perpendicular to an emission surface of the array, that comprises a plurality of emission windows in a first contiguous metallized layer located on the emission surface of the array, each emission window substantially aligned with a respective VCSEL of said array, wherein said first metallized layer in electrical contact with the VCSELs provides a common first electrical contact,and a common second electrical contact located on an opposing non-emission surface, respectively, to the at least one array;

b) a trench located on the non-emission surface of the array, said trench electrically isolating the second electrical contact of the array from an electrical contact region located on the non-emission surface; and

c) an electrically conducting path connecting the first electrical contact located on the emission surface to the electrical contact region located on the non-emission surface, such that the first electrical contact and the second electric contact are coplanar and accessible on the non-emission surface for surface mounting; and

d) a transparent carrier substrate disposed on the emission surface, said transparent carrier substrate further comprising a contiguous metallized electrical contact layer including a second plurality of windows substantially aligned with, and proximal to the plurality of emission windows on the emission surface of the at least one array, such that the emission from the array is directed out of the carrier substrate from a surface distal to the array module.

16. The illuminator module as in claim 15, wherein the electrically conducting path to the electrical contact region on the non-emission surface is effected through a gold bump having a thickness substantially equal to the thickness of the at least one array.

17. The illuminator module as in claim 15, wherein the electrical contact layer disposed on the carrier substrate is electrically connected to the first electrical contact on the emission surface and to the electrical contact region located on the non-emission surface.

18. The illuminator module as in claim 15, wherein the VCSELs are configured in top or bottom emission mode.

19. The illuminator module as in claim 15 further comprising a substrate that physically supports the at least one array, wherein the substrate comprises a thickness that facilitates efficient heat dissipation from the at least one array.

20. The illuminator module as in claim 15 further comprising a substrate that physically supports the at least one array, wherein the substrate comprises a thickness that substantially reduces re-absorption of the light emitted from the at least one array.

21. The illuminator module as in claim 15, further comprising at least one of an array of microlenses or a diffuser positioned on the surface of the carrier substrate distal to the emission surface.

22. The illuminator module as in claim 21 wherein the diffuser surface comprises a scattering surface, a diffractive surface or a holographic surface.

23. The illuminator module as in claim 15 further including one or more additional arrays, the additional arrays being electrically connected to the at least one array.

24. The illuminator module as in claim 15 further comprising an encapsulation disposed over the carrier substrate, wherein the encapsulation comprises an optical device selected from the group consisting of a transparent window, a lens, a lens array and a diffuser.

25. The illuminator module as in claim 15 further comprising a printed circuit board including one or more electronic circuits electrically connected to the array.

26. The illuminator module as in claim 25, wherein the one or more electronic circuits are chosen from the group consisting of current drivers, image sensors, cameras, controllers, and processors.

27. The illuminator module as in claim 25, wherein the illuminator module is configured to include a current driver, a camera, an image sensor, a controller and a processor for constructing a motion sensing or a gesture recognition device.

28. The illuminator module as in claim 25, wherein the printed circuit board includes metalization layers on multiple levels for connecting the one or more electronic circuits placed on different ones of said multiple levels according to their current carrying requirement such that at least one array module is connected to one or more electronic circuits placed at different ones of said multiple levels.

29. The illuminator module as in claim 25 further comprising an encapsulation disposed over the carrier substrate and the one or more electronic circuits, wherein the encapsulation comprises an optical device selected from the group consisting of a transparent window, a lens, a lens array and a diffuser.

30. The illuminator module as in claim 15 further comprising a thermally conducting submount, wherein the illuminator module is surface mounted to the thermally conducting submount.

31. The illuminator module as in claim 15 further comprising an enclosure with a window facing the emission surface, the window comprising at least one of a transparent surface, a microlens array, or a diffuser surface.

32. The illuminator module as in claim 31, wherein the diffuser surface comprises a scattering surface, a diffractive surface, a holographic surface or a combination thereof.

33. An illuminator module comprising:

a) a plurality of Vertical Cavity Surface Emitting Lasers (VCSEL) arrays located monolithically on a common substrate, wherein each one of the plurality of VC SEL array includes a respective common first electrical contact located on a common emission surface and a common second electrical contact located on a common non-emission surface, respectively, said plurality of VCSEL arrays are electrically connected so as to collectively emit light in a direction perpendicular to the emission surface;

b) one or more trenches located on the non-emission surface, said trenches electrically isolating each one the plurality of arrays from a corresponding electrical contact region located on the non-emission surface;

c) one or more electrically conducting paths connecting the respective first electrical contacts located on the emission surface and to the corresponding contact region on the non-emission surface so as to access respective first and second contacts of the plurality of the arrays on the non-emission surface for surface mounting; and

d) a transparent carrier substrate disposed on the emission surface, said transparent carrier substrate further comprising a contiguous metallized electrical contact layer further including a second plurality of emission windows substantially aligned with, and proximal to the plurality of emission windows located on the emission surface of the plurality of VCSEL arrays, such that the plurality of VC SEL arrays emit light collectively out of the carrier substrate from a surface distal to the plurality of arrays.

34. The illuminator module as in claim 33, wherein the one or more electrically conducting path to the contact region on the non-emission surface is effected through a corresponding gold bump having a thickness substantially equal to the thickness of the array.

35. The illuminator module as in claim 33, wherein the electrical contact layer disposed on the carrier substrate is electrically connected to each one of the first electrical contact on the emission surface and to a corresponding electrical contact region located on the non-emission surface.

36. The illuminator module as in claim 33, wherein the plurality of monolithic VCSEL arrays comprise an array chip.

37. The illuminator module as in claim 33, wherein the plurality of VCSEL arrays located monolithically on the common substrate are arranged in one or two dimensional arrays.

38. The illuminator module as in claim 33, wherein the substrate comprises a thickness that facilitates efficient heat dissipation.

39. The illuminator module as in claim 33, further comprising at least one of an array of microlenses or a diffuser positioned proximate to the emission surface.

40. The illuminator module as in claim 39, wherein the diffuser surface further comprises a scattering surface, a diffractive surface, a holographic surface or a combination thereof.

41. The illuminator module as in claim 33 further comprising one or more electronic circuits electrically connected to one or more VC SEL arrays of the plurality of arrays.

42. The illuminator module as in claim 41, wherein the one or more electronic circuits are chosen from the group consisting of current drivers, image sensors, cameras, controllers, and processors.

43. The illuminator module as in claim 41, wherein the illuminator module is configured to include a current driver, a camera, an image sensor, a controller and a processor for constructing a motion sensing or gesture recognition device.

44. The illuminator module as in claim 41, wherein the one or more electronic circuits are electrically connected to conducting paths on multiple levels of a multi-level printed circuit board according to their current carrying requirement for connecting to the one or more of the plurality of arrays.

45. The illuminator module as in claim 33, wherein the illuminator is surface mounted on a thermally conducting submount.

46. The illuminator module as in claim 33 further comprising an enclosure with a window facing the emission surface.

47. The illuminator module as in claim 46, wherein the window comprises at least one of an array of microlenses or a diffuser.

48. The illuminator module as in claim 47, wherein the diffuser further comprises at least one of a scattering surface, a diffractive surface, or a holographic surface.

49. An optical illuminator module comprising:

a) a plurality of Vertical Cavity Surface Emitting Lasers (VCSELs) forming a two-dimensional array of VCSELs having a light emitting surface on a first surface and a bonding surface on a second surface which is opposite to the first surface, one terminal of each of the plurality of VCSELs being electrically connected to a common first terminal of the array of VCSELs and a second terminal of each plurality of VCSELs being electrically connected to a common second terminal of the array of VCSELs, such that all the VCSELs in the array emit light collectively; and

b) a submount including a plurality of bonding pads that are electrically isolated from each other and positioned on a first surface, the plurality of bonding pads being electrically connected to a corresponding plurality of bonding pads located on a second surface of the submount such that the bonding surface of the array when placed on the first surface of the submount is in thermal and electrical contact with the submount.

50. The optical illuminator module of claim 49, wherein the submount is bonded to a heat sink such that the VCSEL array is in thermal contact with the heat sink.

51. The optical illuminator module of claim 49, wherein the plurality of bonding pads positioned on the first surface of the submount are wrapped around one or more edges of the submount, such that the plurality of bonding pads positioned on the first surface is electrically connected to the corresponding plurality of bonding pads positioned on the second surface of the submount.

52. The optical illuminator module of claim 51, wherein the submount is bonded to a heat sink such that the VCSEL array is in thermal contact with the heat sink.

53. The optical illuminator module of claim 49, wherein the plurality of bonding pads positioned on the first surface are wrapped around one or more sides of the submount, such that the plurality of bonding pads positioned on the first surface is electrically connected to the corresponding plurality of bonding pads positioned on the second surface of the submount.

54. The optical illuminator module of claim 49, wherein the plurality of bonding pads positioned on the first surface of the submount are electrically connected to the corresponding plurality of bonding pads positioned on the second surface of the submount by a plurality of via holes.

55. The optical illuminator module of claim 49, wherein the illuminator module is configured to perform at least one of motion sensing, gesture recognition, and three-dimensional sensing function.

56. An optical illuminator system comprising:

a) a printed circuit board including a plurality of transmission lines positioned on a surface of the printed circuit board;

b) a plurality of Vertical Cavity Surface Emitting Lasers (VCSELs) arranged to form array of VCSELs having a light emitting surface on a first surface and a bonding surface on a second surface, wherein a first terminal of each of the plurality of VCSELs is electrically connected to a common first terminal of the array and a second terminal of each plurality of VCSELs is electrically connected to a common second terminal of the array, such that all the VCSELs in the array emit light collectively;

c) a submount electrically bonded to a bonding pad of the printed circuit board, the submount comprising a plurality of bonding pads that are electrically isolated from each other and positioned on a first surface, the common first and the common second terminals of the array being electrically connected to respective first and second bonding pads on the submount, such that the array is in thermal contact with the submount, and the plurality of bonding pads positioned on the first surface are electrically connected to a corresponding plurality of bonding pads located on a second surface of the submount, which is opposite to the first surface of the submount; and

d) an electronic module including at least one current driver circuit electrically bonded to the printed circuit board so that the VCSEL array is electrically connected to the at least one current driver circuit.

57. The optical illuminator module of claim 56, wherein the submount is bonded to a heat sink such that the VCSEL array is in thermal contact with the heat sink.

58. The optical illuminator system of claim 56, wherein the plurality of bonding pads positioned on the first surface are wrapped around one or more edges of the submount, such that the plurality of bonding pads positioned on the first surface is electrically connected to the corresponding plurality of bonding pads positioned on the second surface of the submount.

59. The optical illuminator module of claim 58, wherein the submount is bonded to a heat sink such that the VCSEL array is in thermal contact with the heat sink.