Optical power distribution devices

• US 20060188198A1
• Filed: 12/09/2005
• Published: 08/24/2006
• Est. Priority Date: 12/09/2004
• Status: Active Grant

• Current Assignee: Zetta Research and Development LLC - RPO Series (Zetta Research, LLC)
• Original Assignee: RPO Pty Limited (RPO, Inc.)
• Inventors: Cornish, Benjamin, Charters, Robert B.
• Granted Patent: US 7,421,167 B2
• Time in Patent Office: Days
• US Class Current: 385/39
• CPC Class Codes: G02B 6/12011 characterised by the arrayed waveguides, e.g. comprising a filled groove in the array section
• CPC Class Codes: G02B 6/12014 characterised by the wavefront splitting or combining section, e.g. grooves or optical elements in a slab waveguide
• CPC Class Codes: G02B 6/12019 characterised by the optical interconnection to or from the AWG devices, e.g. integration or coupling with lasers or photodiodes coupling integrated waveguide to fibre G02B6/30, to optoelectronic element G02B6/42; monolithic integration of integrated waveguides with other optical elements G02B6/12004
• CPC Class Codes: G02B 6/125 Bends, branchings or intersections
• CPC Class Codes: G02B 6/2808 using a mixing element which evenly distributes an input signal over a number of outputs
• CPC Class Codes: G02B 6/2813 based on multimode interference effect, i.e. self-imaging
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

This invention relates to optical splitters, particularly to optical splitters for use in optical touch screens. The present invention provides an optical splitter for distributing light substantially equally from a multimode input waveguide to an array of output waveguides, via a slab region. The distribution of output waveguide widths is chosen to complement the intensity distribution in the slab region, which may or may not be substantially uniform. The invention also provides an optical splitter for distributing light substantially equally from an optical source to a plurality of waveguides, wherein said optical source directs a beam of light into a slab region. The distribution of waveguide widths is chosen to complement the intensity distribution in the slab region, which may or may not be substantially uniform. When used to distribute optical power in optical touch screens, the splitters of the present invention may be used in series and/or in parallel.

Claims

1. An optical power splitter for distributing light substantially equally from an optical source to a plurality of output waveguides, the splitter comprising a multimode input waveguide coupled to the optical source, a slab region, and an array of output waveguides, wherein the output waveguides are connected to the slab region along an arc of a circle and point towards the junction of the input waveguide and the slab region, and wherein the splitter is used as a component of an optical touch screen sensor.

2. An optical power splitter according to claim 1, wherein the output waveguides are multimode.

3. An optical power splitter according to claim 1, wherein the output waveguides are singlemode.

4. An optical power splitter according to claim 1, wherein the slab region is wider than the array of output waveguides connected thereto.

5. An optical power splitter according to claim 1, wherein the optical source is selected from a laser, a light emitting diode or a supplementary waveguide.

6. An optical power splitter according to claim 5, wherein the laser is a laser diode or a vertical cavity surface emitting laser.

7. An optical power splitter according to claim 5, wherein the supplementary waveguide is an output waveguide of an optical power splitter thereby to define a multi-stage splitter system.

8. An optical power splitter for distributing light substantially equally from an optical source to a plurality of output waveguides, the splitter comprising a slab region and an array of output waveguides, wherein the optical source launches power directly into the slab region, the output waveguides are connected to the slab region along an arc of a circle and point towards the position where the power enters the slab region, and wherein the splitter is used as a component of an optical touch screen sensor.

9. An optical power splitter according to claim 8, wherein the output waveguides are multimode.

10. An optical power splitter according to claim 8, wherein the output waveguides are singlemode.

11. An optical power splitter according to claim 8, wherein the slab region is wider than the array of output waveguides connected thereto.

12. An optical power splitter according to claim 8, wherein the optical source is selected from laser, a light emitting diode or a supplementary waveguide.

13. An optical power splitter according to claim 12, wherein the laser is a laser diode or a vertical cavity surface emitting laser.

14. An optical power splitter according to claim 12, wherein the supplementary waveguide is an optical fibre or an integrated optical waveguide.

15. An optical power splitter according claim 14, wherein the supplementary waveguide is an output waveguide of an optical power splitter thereby to define a multi-stage splitter system.

16. An optical power splitter for distributing light from an optical source to a plurality of output waveguides, the splitter comprising a multimode input waveguide, a slab region and an array of output waveguides, wherein optical power is coupled from the optical source into the multimode input waveguide, and the distribution of output waveguide widths is chosen such that, when the optical field diffracting in the slab region impinges on the output waveguides, the integral of the optical field over the waveguide cross-sectional area is substantially equal for each output waveguide.

17. An optical power splitter according to claim 16, wherein the output waveguides are connected to the slab region along an arc of a circle and point towards the junction of the input waveguide and the slab region.

18. An optical power splitter according to claim 16, wherein the intensity distribution of the optical field diffracting in the slab region is non-Gaussian.

19. An optical power splitter according to claim 16, wherein the output waveguides are multimode.

20. An optical power splitter according to claim 16, wherein the output waveguides are singlemode.

21. An optical power splitter according to claim 16, wherein the slab region is wider than the array of output waveguides connected thereto.

22. An optical power splitter according to claim 16, wherein the optical source is selected from a laser, a light emitting diode or a supplementary waveguide.

23. An optical power splitter according to claim 22, wherein the laser is a laser diode or a vertical cavity surface emitting laser.

24. An optical power splitter according to claim 22, wherein the supplementary waveguide is an output waveguide of an optical power splitter thereby to define a multi-stage splitter system.

25. An optical power splitter according to claim 16, wherein the splitter is used as a component of an optical touch screen sensor.

26. An optical power splitter for distributing light from an optical source to a plurality of output waveguides, the splitter comprising a slab region and an array of output waveguides wherein the optical source launches power directly into the slab region, the intensity distribution in the slab region is non-Gaussian, and the distribution of output waveguide widths is chosen such that, when the intensity distribution in the slab region impinges on the output waveguides, the integral of the optical field over the waveguide cross-sectional area is substantially equal for each output waveguide.

27. An optical power splitter according to claim 26, wherein the output waveguides are connected to the slab region along an arc of a circle and point towards the position where power enters the slab region.

28. An optical power splitter according to claim 26, wherein the output waveguides are multimode.

29. An optical power splitter according to claim 26, wherein the output waveguides are singlemode.

30. An optical power splitter according to claim 26, wherein the slab region is wider than the array of output waveguides connected thereto.

31. An optical power splitter according to claim 26, wherein the optical source is selected from a laser, a light emitting diode or a supplementary waveguide.

32. An optical power splitter according to claim 31, wherein the laser is a laser diode or a vertical cavity surface emitting laser.

33. An optical power splitter according to claim 31, wherein the supplementary waveguide is an optical fibre or an integrated optical waveguide.

34. An optical power splitter according claim 33, wherein the supplementary waveguide is an output waveguide of an optical power splitter thereby to define a multi-stage splitter system.

35. An optical power splitter according to claim 29, wherein the splitter is used as a component of an optical touch screen sensor.

36. An optical power splitter for distributing light from an optical source to a plurality of optical waveguides, the splitter comprising a slab region and an array of output waveguides, wherein the optical source launches a beam directly into the slab region, and wherein the beam diffracts with an intensity distribution that is substantially uniform in the plane of the slab region such that, when the intensity distribution in the slab region impinges on the output waveguides, the integral of the optical field over the waveguide cross-sectional area is substantially equal for each output waveguide.

37. An optical power splitter according to claim 36, wherein the beam is substantially annular in shape.

38. An optical power splitter according to claim 36, wherein the output waveguides are connected to the slab region along an arc of a circle and point towards the position where the beam enters the slab region.

39. An optical power splitter according to claim 36, wherein the output waveguides are multimode.

40. An optical power splitter according to claim 36, wherein the output waveguides are singlemode.

41. An optical power splitter according to claim 36, wherein the slab region is wider than the array of output waveguides connected thereto.

42. An optical power splitter according to claim 36, wherein the output waveguides are uniform in width.

43. An optical power splitter according to claim 36, wherein the optical source is selected from a laser, a light emitting diode or a supplementary waveguide with an annular core.

44. An optical power splitter according to claim 43, wherein the laser is a laser diode or a vertical cavity surface emitting laser.

45. An optical power splitter according to claim 43, wherein the supplementary waveguide is an optical fibre or an integrated optical waveguide.

46. An optical power splitter according claim 45, wherein the supplementary waveguide is an output waveguide of an optical power splitter thereby to define a multi-stage splitter system.

47. An optical power splitter according to claim 36, wherein the splitter is used as a component of an optical touch screen sensor.

48. An input device for an electronic device comprising:

an optical source;

at least one light detector to detect light intensity at a plurality of light detecting elements;

an input area defining a plane; and

at least one optical power splitter for distributing light substantially equally from the optical source to a plurality of output waveguides, each splitter comprising a multimode input waveguide coupled to the optical source, a slab region, and an array of output waveguides, wherein the output waveguides are connected to the slab region along an arc of a circle, and point towards the junction of the input waveguide and the slab region.

49. An input device according to claim 48, wherein the output waveguides are multimode.

50. An input device according to claim 48, wherein the output waveguides are singlemode.

51. An input device according to claim 48, wherein the slab region is wider than the array of output waveguides connected thereto.

52. An input device according to claim 48, wherein the optical source is selected from a laser, a light emitting diode or a supplementary waveguide.

53. An input device according to claim 52, wherein the laser is a laser diode or a vertical cavity surface emitting laser.

54. An input device according to claim 52, wherein the supplementary waveguide is an output waveguide of an optical power splitter thereby to define a multi-stage splitter system.

55. An input device according to claim 48, wherein the input device is an optical touch screen sensor.

56. An input device for an electronic device comprising:

an optical source;

at least one light detector to detect light intensity at a plurality of light detecting elements;

an input area defining a plane; and

at least one optical power splitter for distributing light substantially equally from the optical source to a plurality of output waveguides, each splitter comprising a slab region and an array of output waveguides, wherein the optical source launches power directly into the slab region, and wherein the output waveguides are connected to the slab region along an arc of a circle, and point towards the position where the power enters the slab waveguide.

57. An input device according to claim 56, wherein the output waveguides are multimode.

58. An input device according to claim 56, wherein the output waveguides are singlemode.

59. An input device according to claim 56, wherein the slab region is wider than the array of output waveguides connected thereto.

60. An input device according to claim 56, wherein the optical source is selected from a laser, a light emitting diode or a supplementary waveguide.

61. An input device according to claim 60, wherein the laser is a laser diode or a vertical cavity surface emitting laser.

62. An input device according to claim 60, wherein the supplementary waveguide is an optical fibre or an integrated optical waveguide.

63. An input device according claim 62, wherein the supplementary waveguide is an output waveguide of an optical power splitter thereby to define a multi-stage splitter system.

64. An input device according to claim 56, wherein the input device is an optical touch screen sensor.

65. An input device for an electronic device comprising:

an optical source;

at least one light detector to detect light intensity at a plurality of light detecting elements;

an input area defining a plane; and

at least one optical power splitter for distributing light from the optical source to a plurality of output waveguides, each splitter having a multimode input waveguide, a slab region and an array of output waveguides wherein optical power is coupled from the optical source into the multimode input waveguide, and the distribution of output waveguide widths is chosen such that, when the optical field diffracting in the slab region impinges on the output waveguides, the integral of the optical field over the waveguide cross-sectional area is substantially equal for each output waveguide.

66. An input device according to claim 65, wherein the output waveguides are connected to the slab region along an arc of a circle and point towards the junction of the input waveguide and the slab region.

67. An input device according to claim 65, wherein the intensity distribution of the optical field diffracting in the slab region is non-Gaussian.

68. An input device according to claim 65, wherein the output waveguides are multimode.

69. An input device according to claim 65, wherein the output waveguides are singlemode.

70. An input device according to claim 65, wherein the slab region is wider then the array of output waveguides connected thereto.

71. An input device according to claim 65, wherein the optical source is selected from a laser, a light emitting diode or a supplementary waveguide.

72. An input device according to claim 71, wherein the laser is a laser diode or a vertical cavity surface emitting laser.

73. An input device according to claim 71, wherein the supplementary waveguide is an output waveguide of an optical power splitter thereby to define a multi-stage splitter system.

74. An input device according to claim 65, wherein the input device is an optical touch screen sensor.

75. An input device for an electronic device comprising:

an optical source;

at least one light detector to detect light intensity at a plurality of light detecting elements;

an input area defining a plane; and

at least one optical power splitter for distributing light from the optical source to a plurality of output waveguides, each splitter having a slab region and an array of output waveguides wherein the optical source launches power directly into the slab region, the intensity distribution in the slab region is non-Gaussian, and the distribution of output waveguide widths is chosen such that, when the intensity distribution in the slab region impinges on the output waveguides, the integral of the optical field over the waveguide cross-sectional area is substantially equal for each output waveguide.

76. An input device according to claim 75, wherein the output waveguides are connected to the slab region along an arc of a circle and point towards the position where power enters the slab region.

77. An input device according to claim 75, wherein the output waveguides are multimode.

78. An input device according to claim 75, wherein the output waveguides are singlemode.

79. An input device according to claim 75, wherein the slab region is wider then the array of output waveguides connected thereto.

80. An input device according to claim 75, wherein the optical source is selected from a laser, a light emitting diode or a supplementary waveguide.

81. An input device according to claim 80, wherein the laser is a laser diode or a vertical cavity surface emitting laser.

82. An input device according to claim 80, wherein the supplementary waveguide is an optical fibre or an integrated optical waveguide.

83. An input device according claim 82, wherein the supplementary waveguide is an output waveguide of an optical power splitter thereby to define a multi-stage splitter system.

84. An input device according to claim 75, wherein the input device is an optical touch screen sensor.

85. An input device for an electronic device comprising:

an optical source;

at least one light detector to detect light intensity at a plurality of light detecting elements;

an input area defining a plane; and

at least one optical power splitter for distributing light from the optical source to a plurality of optical waveguides, each splitter comprising a slab region and an array of output waveguides, wherein the optical source launches a beam directly into the slab region, and wherein the beam diffracts with an intensity distribution that is substantially uniform in the plane of the slab region such that, when the intensity distribution in the slab region impinges on the output waveguides, the integral of the optical field over the waveguide cross-sectional area is substantially equal for each output waveguide.

86. An input device according to claim 85, wherein the beam is substantially annular in shape.

87. An input device according to claim 85, wherein the output waveguides are connected to the slab region along an arc of a circle and point towards the position where the beam enters the slab region.

88. An input device according to claim 85, wherein the output waveguides are multimode.

89. An input device according to claim 85, wherein the output waveguides are singlemode.

90. An input device according to claim 85, wherein the slab region is wider then the array of output waveguides connected thereto.

91. An input device according to claim 85, wherein the output waveguides are uniform in width.

92. An input device according to claim 85, wherein the optical source is selected from a laser, a light emitting diode or a supplementary waveguide with an annular core.

93. An input device according to claim 92, wherein the laser is a laser diode or a vertical cavity surface emitting laser.

94. An input device according to claim 92, wherein the supplementary waveguide is an optical fibre or an integrated optical waveguide.

95. An input device according claim 94, wherein the supplementary waveguide is an output waveguide of an optical power splitter thereby to define a multi-stage splitter system.

96. An input device according to claim 85, wherein the input device is an optical touch screen sensor.