Optical junction apparatus and methods employing optical power transverse-transfer

1. An optical apparatus, comprising:

an optical device on a substrate;

an external-transfer optical waveguide, the external-transfer optical waveguide including an optical junction region; and

a transmission optical waveguide, the transmission optical waveguide including an optical junction region,

the optical device and the external-transfer optical waveguide being optically integrated for enabling transfer of optical power therebetween,

the transmission optical waveguide and the external-transfer optical waveguide being adapted for and positioned for enabling transverse-transfer of optical power therebetween at the respective optical junction regions,

the optical junction region of the transmission optical waveguide or the external-transfer optical waveguide being adapted for enabling mode-interference-coupled transverse-transfer of optical power between the transmission optical waveguide and the external-transfer optical waveguide.

2. The apparatus of claim 1 , the transmission optical waveguide or the external-transfer optical waveguide being adapted for maintaining transverse-offset optical power transfer loss therebetween below about 0.5 dB for transverse offsets at least as large as about ±0.5 times a corresponding transverse optical mode size characteristic of the transmission optical waveguide and the external-transfer optical waveguide.

3. An optical apparatus, comprising:

an optical device on a substrate;

an external-transfer optical waveguide, the external-transfer optical waveguide including an optical junction region; and

a transmission optical waveguide, the transmission optical waveguide including an optical junction region,

the optical device and the external-transfer optical waveguide being optically integrated for enabling transfer of optical power therebetween,

the transmission optical waveguide or the external-transfer optical waveguide being adapted for and positioned for enabling transverse-transfer of optical power therebetween at the respective optical junction regions,

the optical junction region of the transmission optical waveguide or the external-transfer optical waveguide being adapted for enabling substantially adiabatic transverse-transfer of optical power between the transmission optical waveguide and the external-transfer optical waveguide.

4. The apparatus of claim 3 , the transmission optical waveguide or the external-transfer optical waveguide being adapted for maintaining transverse-offset optical power transfer loss therebetween below about 0.5 dB for transverse offsets at least as large as about ±1.0 times a corresponding transverse optical mode size characteristic of the transmission optical waveguide and the external-transfer optical waveguide.

5. The apparatus of claim 3 , the transmission optical waveguide or the external-transfer optical waveguide being adapted for maintaining transverse-offset optical power transfer loss therebetween below about 0.5 dB for transverse offsets at least as large as about ±1.5 times a corresponding transverse optical mode size characteristic of the transmission optical waveguide and the external-transfer optical waveguide.

6. The apparatus of claim 3 , the transmission optical waveguide or the external-transfer optical waveguide being adapted for maintaining transverse-offset optical power transfer loss therebetween within about ±0.5 dB of a nominal optical power transfer loss level for transverse offsets at least as large as about ±0.7 times a corresponding transverse optical mode size characteristic of the transmission optical waveguide and the external-transfer optical waveguide.

7. The apparatus of claim 3 , the transmission optical waveguide or the external-transfer optical waveguide being adapted for maintaining transverse-offset optical power transfer loss therebetween within about ±0.5 dB of a nominal optical power transfer loss level for transverse offsets at least as large as about ±1.0 times a corresponding transverse optical mode size characteristic of the transmission optical waveguide and the external-transfer optical waveguide.

8. The apparatus of claim 3 , the transmission optical waveguide or the external-transfer optical waveguide being adapted for maintaining transverse-offset optical power transfer loss therebetween within about ±0.5 dB of a nominal optical power transfer loss level for transverse offsets at least as large as about ±1.5 times a corresponding transverse optical mode size characteristic of the transmission optical waveguide and the external-transfer optical waveguide.

9. The apparatus of claim 1 or 3 ,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling end-transfer of optical power between the optical device and the external-transfer optical waveguide,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling substantially spatial-mode-matched end-transfer of optical power between the optical device and the external-transfer optical waveguide.

10. The apparatus of claim 1 or 3 ,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling end-transfer of optical power between the optical device and the external-transfer optical waveguide,

at least a portion of the external-transfer optical waveguide being formed by quantum-well inter-mixing of a portion of the optical device.

11. The apparatus of claim 1 or 3 , the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling transverse-transfer of optical power between the optical device and the external-transfer optical waveguide.

12. The apparatus of claim 1 or 3 , at least a portion of the external-transfer optical waveguide being a low-modal-index optical waveguide.

13. The apparatus of claim 1 or 3 , at least a portion of the external-transfer optical waveguide being a high-modal-index optical waveguide.

14. The apparatus of claim 1 or 3 , at least a portion of the external-transfer optical waveguide including a core and lower-index cladding.

15. The apparatus of claim 14 , at least a portion or the cladding including a metal film.

16. The apparatus of claim 1 or 3 , at least a portion of the external-transfer optical waveguide including a multi-layer waveguide structure, the multi-layer waveguide structure including at least one multi-layer reflector stack.

17. The apparatus of claim 1 or 3 , at least a portion of the transmission optical waveguide being a low-modal-index optical waveguide.

18. The apparatus of claim 1 or 3 , at least a portion of the transmission optical waveguide being a high-modal-index optical waveguide.

19. The apparatus of claim 1 or 3 , at least a portion of the transmission optical waveguide including a core and lower-index cladding.

20. The apparatus of claim 19 , at least a portion of the cladding including a metal film.

21. The apparatus of claim 1 or 3 , at least a portion of the transmission optical waveguide including a multi-layer waveguide structure, the multi-layer waveguide structure including at least one multi-layer reflector stack.

22. The apparatus of claim 1 or 3 , the transmission optical waveguide being adapted at an end thereof for enabling end-transfer of optical power to a single-mode optical fiber.

23. The apparatus of claim 1 or 3 , the transmission optical waveguide being a planar waveguide on a waveguide substrate.

24. The apparatus of claim 23 , the transmission optical waveguide being one of multiple planer waveguides on the waveguide substrate, the multiple planar waveguides forming a planar waveguide circuit.

25. The apparatus of claim 1 or 3 , the transmission optical waveguide being an optical fiber, the optical fiber having a fiber-optic-taper segment, the optical junction region of the optical fiber including at least a portion of the fiber-optic-taper segment.

26. The apparatus of claim 1 or 3 , the transmission optical waveguide being an optical fiber, at least a portion of the optical junction region thereof having cladding transversely asymmetrically removed therefrom.

27. The apparatus of claim 1 or 3 , the transmission optical waveguide being an optical fiber, the optical junction region thereof being a beveled end thereof.

28. An optical apparatus, comprising:

an optical device on a substrate;

an external-transfer optical waveguide, the external-transfer optical waveguide including an optical junction region; and

a transmission optical waveguide, the transmission optical waveguide including an optical junction region,

the optical device and the external-transfer optical waveguide being optically integrated for enabling transfer of optical power therebetween,

the transmission optical waveguide or the external-transfer optical waveguide being adapted for and positioned for enabling transverse-transfer of optical power therebetween at the respective optical junction regions,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling end-transfer of optical power between the optical device and the external-transfer optical waveguide,

the optical device having an etched end face, the etched end face serving at least in part to adapt the optical device for enabling end-transfer of optical power between the optical device and the external-transfer optical waveguide.

29. An optical apparatus, comprising:

an optical device on a substrate;

an external-transfer optical waveguide, the external-transfer optical waveguide including an optical junction region; and

a transmission optical waveguide, the transmission optical waveguide including an optical junction region,

the optical device and the external-transfer optical waveguides being optically integrated for enabling transfer of optical power therebetween,

the transmission optical waveguides or the external-transfer optical waveguide being adapted for and positioned for enabling transverse-transfer of optical power therebetween at the respective optical junction regions,

at least a portion of the transmission optical waveguide being adapted for providing a portion of functionality of the optical device.

30. An optical apparatus comprising:

an optical device on a substrate;

an external-transfer optical waveguide, the external-transfer optical waveguide including an optical junction region; and

a transmission optical waveguide, the transmission optical waveguide including an optical junction region,

the optical device and the external-transfer optical waveguide being optically integrated for enabling transfer of optical power therebetween,

the transmission optical waveguide or the external-transfer optical waveguide being adapted for and positioned for enabling transverse-transfer of optical power therebetween at the respective optical junction regions,

at least a portion of the external-transfer optical waveguide being adapted for providing a portion of functionality of the optical device.

31. An optical apparatus, comprising:

an optical device on a substrate;

a first external-transfer optical waveguide, the first external-transfer optical waveguide including an optical junction region;

a second external-transfer optical waveguide, the second external-transfer optical waveguide including an optical junction region;

a first transmission optical waveguide, the first transmission optical waveguide including an optical junction region; and

a second transmission optical waveguide, the second transmission optical waveguide including an optical junction region,

the optical device and the first external-transfer optical waveguide being optically integrated for enabling transfer of optical power therebetween,

the optical device and the second external-transfer optical waveguide being optically integrated for enabling transfer of optical power therebetween,

the first transmission optical waveguide or the first external-transfer optical waveguide being adapted for and positioned for enabling transverse-transfer of optical power therebetween at the respective optical junction regions thereof,

the second transmission optical waveguide or the second external-transfer optical waveguide being adapted for and positioned for enabling transverse-transfer of optical power therebetween at the respective optical junction regions thereof.

32. The apparatus of claim 31 , the first transmission optical waveguide or the second transmission optical waveguide being assembled with the substrate, the optical device, the first external-transfer optical waveguide, or the second external-transfer optical waveguide, so as to position the respective optical junction regions for enabling transverse-transfer of optical power: i) between the first transmission optical waveguide and the first external-transfer optical waveguide, or ii) between the second transmission optical waveguide and the second external-transfer optical waveguide.

33. The apparatus of claim 31 , further comprising a joining element, the joining element securing the first transmission optical waveguide or the second transmission optical waveguide to the substrate, the optical device, the first external-transfer optical waveguide, or the second external-transfer optical waveguide, so as to position the respective optical junction regions for enabling transverse-transfer of optical power: i) between the first transmission optical waveguide and the first external-transfer optical waveguide, or ii) between the second transmission optical waveguide and the second external-transfer optical waveguide.

34. The apparatus of claim 31 , the optical device, the first external-transfer optical waveguide, or the second external-transfer optical waveguide being adapted for and positioned for enabling end-transfer of optical power between the optical device and: i) the first external-transfer optical waveguide, or ii) the second external-transfer optical waveguide.

35. The apparatus of claim 31 , the optical device, the first external-transfer optical waveguide, or the second external-transfer optical waveguide being adapted for and positioned for enabling transverse-transfer of optical power between the optical device and: i) the first external-transfer optical waveguide, or ii) the second external-transfer optical waveguide.

36. The apparatus of claim 31 , the first transmission optical waveguide, the second transmission optical waveguide, the first external-transfer optical waveguide, or the second external-transfer optical waveguide being adapted for and positioned for enabling mode-interference-coupled transverse-transfer of optical power: i) between the first transmission optical waveguide and the first external-transfer optical waveguide at their respective optical junction regions, or ii) between the second transmission optical waveguide and the second external-transfer optical waveguide at their respective optical junction regions.

37. The apparatus of claim 31 , the first transmission optical waveguide, the second transmission optical waveguide, the first external-transfer optical waveguide, or the second external-transfer optical waveguide being adapted for and positioned for enabling substantially adiabatic transverse-transfer of optical power: i) between the first transmission optical waveguide and the first external-transfer optical waveguide at their respective optical junction regions, or ii) between the second transmission optical waveguide and the second external-transfer optical waveguide at their respective optical junction regions.

38. The apparatus of claim 31 , the first transmission optical waveguide or the second transmission optical waveguide being a planar waveguide on a waveguide substrate.

39. The apparatus of claim 31 , the first and second transmission optical waveguides being parts of a common component, the common component being provided initially mechanically separate from the substrate and subsequently assembled with the substrate.

40. The apparatus of claim 39 , the first and second transmission optical waveguides being planar waveguides on a common waveguide substrate.

41. The apparatus of claim 31 , at least a portion of the first transmission optical waveguide or the second transmission optical waveguide being adapted for providing a portion of functionality of the optical device.

42. The apparatus of claim 31 , at least a portion of the first external-transfer optical waveguide or the second external-transfer optical waveguide being adapted for providing a portion of functionality of the optical device.

43. An optical apparatus, comprising:

an optical device on a device substrate; and

an external-transfer optical waveguide, the external-transfer optical waveguide including an optical junction region,

the optical device and the external-transfer optical waveguide being optically integrated for enabling transfer of optical power therebetween,

the optical junction region of the external-transfer optical waveguide being adapted for enabling transverse-transfer of optical power between the external-transfer optical waveguide and a second optical waveguide at the optical junction region,

the device substrate, the optical device, or the external-transfer optical waveguide being adapted for receiving and positioning the second optical waveguide relative to the optical junction region of the external-transfer optical waveguide so as to enable transverse-transfer of optical power therebetween,

the external-transfer optical waveguide being adapted for enabling substantially adiabatic transverse-transfer of optical power between the external-transfer optical waveguide and the second optical waveguide at the optical junction region.

44. The apparatus of claim 43 , at least a portion of the external-transfer optical waveguide including a core and lower-index cladding, at least one transverse dimension of the core or the cladding varying longitudinally along at least a portion of the optical junction region thereof.

45. The apparatus of claim 43 , at least a portion of the external-transfer optical waveguide including a core and lower-index cladding, a refractive index of the core or the cladding varying longitudinally along at least a portion of the optical junction region thereof.

46. The apparatus of claim 43 , at least a portion of the optical junction region of the external-transfer optical waveguide being beveled.

47. The apparatus of claim 43 , transverse-transfer of optical power being wavelength-dependent.

48. The apparatus of claim 43 , transverse-transfer of optical power being polarization-dependent.

49. An optical apparatus, comprising:

an optical device on a device substrate; and

an external-transfer optical waveguide, the external-transfer optical waveguide including an optical junction region,

the optical device and the external-transfer optical waveguide being optically integrated for enabling transfer of optical power therebetween,

the optical junction region of the external-transfer optical waveguide being adapted for enabling transverse-transfer of optical power between the external-transfer optical waveguide and a second optical waveguide at the optical junction region,

the device substrate, the optical device, or the external-transfer optical waveguide being adapted for receiving and positioning the second optical waveguide relative to the optical junction region of the external-transfer optical waveguide so as to enable transverse-transfer of optical power therebetween,

the external-transfer optical waveguide being adapted for enabling mode-interference-coupled transverse-transfer of optical power between the external-transfer optical waveguide and the second optical waveguide at the optical junction region.

50. The apparatus of claim 49 , modal-index-matching being achieved passively.

51. The apparatus of claim 49 , modal-index-matching being achieved actively.

52. The apparatus of claim 49 , transverse-transfer of optical power being polarization-dependent.

53. The apparatus of claim 49 , transverse-transfer of optical power being wavelength-dependent.

54. The apparatus of claim 43 or 49 ,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling end-transfer of optical power between the optical device and the external-transfer optical waveguide,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling substantially spatial-mode-matched end-transfer of optical power between the optical device and the external-transfer optical waveguide.

55. The apparatus of claim 43 or 49 ,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling end-transfer of optical power between the optical device and the external-transfer optical waveguide,

at least a portion of the external-transfer optical waveguide being formed by quantum-well inter-mixing of a portion of the optical device.

56. The apparatus of claim 43 or 49 , the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling transverse-transfer of optical power between the optical device and the external-transfer optical waveguide.

57. The apparatus of claim 43 or 49 , at least a portion of the external-transfer optical waveguide being a low-modal-index optical waveguide.

58. The apparatus of claim 57 , at least a portion of the external-transfer optical waveguide being a silica-based optical waveguide.

59. The apparatus of claim 57 , at least a portion of the external-transfer optical waveguide being a polymer-based optical waveguide.

60. The apparatus of claim 43 or 49 , at least a portion of the external-transfer optical waveguide being a high-modal-index optical waveguide.

61. The apparatus of claim 60 , at least a portion of the external-transfer optical waveguide being a semiconductor-based optical waveguide.

62. The apparatus of claim 60 , at least a portion of the external-transfer optical waveguide being a silicon semiconductor-based optical waveguide.

63. The apparatus of claim 60 , at least a portion of the external-transfer optical waveguide being a III/V semiconductor-based optical waveguide.

64. The apparatus of claim 43 or 49 , at least a portion of the external-transfer optical waveguide including a core and lower-index cladding.

65. The apparatus of claim 64 , at least a portion of the core or the cladding including silica-based material.

66. The apparatus of claim 64 , at least a portion of the core or the cladding including silicon oxynitride.

67. The apparatus of claim 64 , at least a portion of the core including silicon nitride.

68. The apparatus of claim 64 , the core or the cladding including polymer-based material.

69. The apparatus of claim 64 , the core or the cladding including semiconductor-based material.

70. The apparatus of claim 64 , the core or the cladding including silicon semiconductor-based material.

71. The apparatus of claim 64 , the core or the cladding including a III/V semiconductor-based material.

72. The apparatus of claim 64 , at least a portion of the external-transfer optical waveguide including multiple cores and lower-index cladding.

73. The apparatus of claim 64 , at least a portion of the cladding including a metal film.

74. The apparatus of 43 or 49 , at least a portion of the external-transfer optical waveguide including a multi-layer waveguide structure, the multi-layer waveguide structure including at least one multi-layer reflector stack.

75. The apparatus of claim 43 or 49 , at least a portion of the external-transfer optical waveguide being adapted for spatial mode expansion.

76. An optical apparatus, comprising:

an optical device on a device substrate; and

an external-transfer optical waveguide, the external-transfer optical waveguide including an optical junction region,

the optical device and the external-transfer optical waveguide being optically integrated for enabling transfer of optical power therebetween,

the optical junction region of the external-transfer optical waveguide being adapted for enabling transverse-transfer of optical power between the external-transfer optical waveguide and a second optical waveguide at the optical junction region,

the device substrate, the optical device, or the external-transfer optical waveguide being adapted for receiving and positioning the second optical waveguide relative to the optical junction region of the external-transfer optical waveguide so as to enable transverse-transfer of optical power therebetween,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling end-transfer of optical power between the optical device and the external-transfer optical waveguide,

the optical device having an etched end face, the etched end face serving at least in part to adapt the optical device for enabling end-transfer of optical power between the optical device and the external-transfer optical waveguide.

77. An optical apparatus, comprising:

an optical device on a device substrate; and

an external-transfer optical waveguide, the external-transfer optical waveguide including an optical junction region,

the optical device and the external-transfer optical waveguide being optically integrated for enabling transfer of optical power therebetween,

the optical junction region of the external-transfer optical waveguide being adapted for enabling transverse-transfer of optical power between the external-transfer optical waveguide and a second optical waveguide at the optical junction region,

the device substrate, the optical device, or the external-transfer optical waveguide being adapted for receiving and positioning the second optical waveguide relative to the optical junction region of the external-transfer optical waveguide so as to enable transverse-transfer of optical power therebetween,

at least a portion of the external-transfer optical waveguide being adapted for providing a portion of functionality of the optical device.

78. The apparatus of claim 77 , at least a portion of the external-transfer optical waveguide being adapted for providing at least a portion of wavelength-specific functionality of the optical device.

79. The apparatus of claim 77 , the external-transfer optical waveguide including a waveguide grating.

80. The apparatus of claim 77 , the external-transfer optical waveguide including a thermo-optic element.

81. The apparatus of claim 77 , at least a portion of the external-transfer optical waveguide being adapted for providing at least a portion of polarization-specific functionality of the optical device.

82. The apparatus of claim 77 , at least a portion of the external-transfer optical waveguide being adapted for providing optical power monitoring for the optical device.

83. The apparatus of claim 77 , at least a portion of the external-transfer optical waveguide being adapted for providing at least a portion of spatial-mode-specific functionality of the optical device.

84. The apparatus of claim 77 , the external-transfer optical waveguide including a thermal compensator.

85. The apparatus of claim 77 , the optical device including a laser source.

86. The apparatus of claim 85 , at least a portion of the external-transfer optical waveguide being adapted for providing at least a portion of wavelength selectivity of the laser source.

87. The apparatus of claim 85 , at least a portion of the external-transfer optical waveguide being adapted for providing at least a portion of spatial-mode selectivity of the laser source.

88. The apparatus of claim 85 , at least a portion of the external-transfer optical waveguide being adapted for providing at least a portion of polarization selectivity of the laser source.

89. A method for fabricating an optical apparatus, the method comprising the steps of:

fabricating an optical device on a substrate;

fabricating an external-transfer optical waveguide on the substrate or the optical device, the external-transfer optical waveguide including an optical junction region; and

assembling a transmission optical waveguide with the optical device and the external-transfer optical waveguide, the transmission optical waveguide including an optical junction region,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling transfer of optical power between the optical device and the external-transfer optical waveguide,

the transmission optical waveguide or the external-transfer optical waveguide being adapted for enabling transverse-transfer of optical power between the transmission optical waveguide and the external-transfer optical waveguide at the respective optical junction regions,

the transmission optical waveguide and the external-transfer optical waveguide being positioned, upon assembly of the transmission optical waveguide with the substrate and the external-transfer optical waveguide, so as to position the respective optical junction regions for enabling transverse-transfer of optical power between the transmission optical waveguide and the external-transfer optical waveguide,

the optical junction region of the transmission optical waveguide or the external-transfer optical waveguide being adapted for enabling mode-interference-coupled transverse-transfer of optical power between the transmission optical waveguide and the external-transfer optical waveguide.

90. A method for fabricating an optical apparatus, the method comprising the steps of:

fabricating an optical device on a substrate;

fabricating an external-transfer optical waveguide on the substrate or the optical device, the external-transfer optical waveguide including an optical junction region; and

assembling a transmission optical waveguide with the optical device and the external-transfer optical waveguide, the transmission optical waveguide including an optical junction region,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling transfer of optical power between the optical device and the external-transfer optical waveguide,

the transmission optical waveguide or the external-transfer optical waveguide being adapted for enabling transverse-transfer of optical power between the transmission optical waveguide and the external-transfer optical waveguide at the respective optical junction regions,

the transmission optical waveguide and the external-transfer optical waveguide being positioned, upon assembly of the transmission optical waveguide with the substrate and the external-transfer optical waveguide, so as to position the respective optical junction regions for enabling transverse-transfer of optical power between the transmission optical waveguide and the external-transfer optical waveguide,

the optical junction region of the transmission optical waveguide or the external transfer optical waveguide being adapted for enabling substantially adiabatic transverse-transfer of optical power between the transmission optical waveguide and the external-transfer optical waveguide.

91. The method of claim 89 or 90 ,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling end-transfer of optical power between the optical device and the external-transfer optical waveguide,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling substantially spatial-mode-matched end-transfer of optical power between the optical device and the external-transfer optical waveguide.

92. The method of claim 89 or 90 ,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling end-transfer of optical power between the optical device and the external-transfer optical waveguide,

further including the step of forming at least a portion of the external-transfer optical waveguide by quantum-well inter-mixing of a portion of the optical device.

93. The method of claim 89 or 90 , the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling transverse-transfer of optical power between the optical device and the external-transfer optical waveguide.

94. The method of claim 89 or 90 , at least a portion of the external-transfer optical waveguide being a low-modal-index optical waveguide.

95. The method of claim 89 or 90 , at least a portion of the external-transfer optical waveguide being a high-modal-index optical waveguide.

96. The method of claim 89 or 90 , at least a portion of the external-transfer optical waveguide including a core and lower-index cladding.

97. The method of claim 96 , at least a portion of the cladding including a metal film.

98. The method of claim 89 or 90 , at least a portion of the external-transfer optical waveguide including a multi-layer waveguide structure, the multi-layer waveguide structure including at least one multi-layer reflector stack.

99. The method of claim 89 or 90 , at least a portion of the transmission optical waveguide being a low-modal-index optical waveguide.

100. The method of claim 89 or 90 , at least a portion of the transmission optical waveguide being a high-modal-index optical waveguide.

101. The method of claim 89 or 90 , at least a portion of the transmission optical waveguide including a core and lower-index cladding.

102. The method of claim 101 , at least a portion of the cladding including a metal film.

103. The method of claim 89 or 90 , at least a portion of the transmission optical waveguide including a multi-layer waveguide structure, the multi-layer waveguide structure including at least one multi-layer reflector stack.

104. The method of claim 89 or 90 , the transmission optical waveguide being adapted at an end thereof for enabling end-transfer of optical power to a single-mode optical fiber.

105. The method of claim 89 or 90 , the transmission optical waveguide being a planar waveguide on a waveguide substrate.

106. The method of claim 105 , the transmission optical waveguide being one of multiple planar waveguides on the substrate, the multiple planar waveguides forming a planar waveguide circuit.

107. The method of claim 89 or 90 , the transmission optical waveguide being an optical fiber, the optical fiber having a fiber-optic-taper segment, the optical junction region of the optical fiber including at least a portion of the fiber-optic-taper segment.

108. The method of claim 89 or 90 , the transmission optical waveguide being an optical fiber, at least a portion of the optical junction region thereof having cladding transversely asymmetricaly removed therefrom.

109. The method of claim 89 or 90 , the transmission optical waveguide being an optical fiber, the optical junction region thereof being a beveled end thereof.

110. A method for fabricating an optical apparatus, the method comprising the steps of:

fabricating an optical device on a substrate;

fabricating an external-transfer optical waveguide on the substrate or the optical device, the external-transfer optical waveguide including an optical junction region; and

assembling a transmission optical waveguide with the optical device and the external-transfer optical waveguide, the transmission optical waveguide including an optical junction region,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling transfer of optical power between the optical device and the external-transfer optical waveguide,

the transmission optical waveguide or the external-transfer optical waveguide being adapted for enabling transverse-transfer of optical power between the transmission optical waveguide and the external-transfer optical waveguide at the respective optical junction regions,

the transmission optical waveguide and the external-transfer optical waveguide being positioned, upon assembly of the transmission optical waveguide with the substrate and the external-transfer optical waveguide, so as to position the respective optical junction regions for enabling transverse-transfer of optical power between the transmission optical waveguide and the external-transfer optical waveguide,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling end-transfer of optical power between the optical device and the external-transfer optical waveguide,

further including the step of etching an end face of the optical device so as to at least in part adapt the optical device for enabling end-transfer of optical power between the optical device and the external-transfer optical waveguide.

111. A method for fabricating an optical apparatus, the method comprising the steps of:

fabricating an optical device on a substrate;

fabricating an external-transfer optical waveguide on the substrate or the optical device, the external-transfer optical waveguide including an optical junction region; and

assembling a transmission optical waveguide with the optical device and the external-transfer optical waveguide, the transmission optical waveguide including an optical junction region,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling transfer of optical power between the optical device and the external-transfer optical waveguide,

the transmission optical waveguide or the external-transfer optical waveguide being adapted for enabling transverse-transfer of optical power between the transmission optical waveguide and the external-transfer optical waveguide at the respective optical junction regions,

the transmission optical waveguide and the external-transfer optical waveguide being positioned, upon assembly of the transmission optical waveguide with the substrate and the external-transfer optical waveguide, so as to position the respective optical junction regions for enabling transverse-transfer of optical power between the transmission optical waveguide and the external-transfer optical waveguide,

at least a portion of the transmission optical waveguide being adapted for providing a portion of functionality of the optical device and for enabling operation of the optical device.

112. A method for fabricating an optical apparatus the method comprising the steps of:

fabricating an optical device on a substrate;

fabricating an external-transfer optical waveguide on the substrate or the optical device, the external-transfer optical waveguide including an optical junction region; and

assembling a transmission optical waveguide with the optical device and the external-transfer optical waveguide, the transmission optical waveguide including an optical junction region,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling transfer of optical power between the optical device and the external-transfer optical waveguide,

the transmission optical waveguide or the external-transfer optical waveguide being adapted for enabling transverse-transfer of optical power between the transmission optical waveguide and the external-transfer optical waveguide at the respective optical junction regions,

the transmission optical waveguide and the external-transfer optical waveguide being positioned, upon assembly of the transmission optical waveguide with the substrate and the external-transfer optical waveguide, so as to position the respective optical junction regions for enabling transverse-transfer or optical power between the transmission optical waveguide and the external-transfer optical waveguide,

at least a portion of the external-transfer optical waveguide being adapted for providing a portion of functionality of the optical device and for enabling operation of the optical device.

113. A method for fabricating an optical apparatus, comprising the steps of:

fabricating an optical device on a device substrate;

fabricating an external-transfer optical waveguide on the device substrate or on the optical device, the external-transfer optical waveguide including an optical junction region,

the optical device or the external-transfer optical waveguide being adapted for enabling transfer of optical power therebetween,

the external-transfer optical waveguide being positioned relative to the optical device so as to enable transfer of optical power therebetween,

the optical junction region of the external-transfer optical waveguide being adapted for enabling transverse-transfer of optical power between the external-transfer optical waveguide and a second optical waveguide,

the device substrate, the optical device, or the external-transfer optical waveguide being adapted for receiving and positioning the second optical waveguide relative to the optical junction region of the external-transfer optical waveguide so as to enable transverse-transfer of optical power therebetween, the second optical waveguide being provided initially as a mechanically separate component and subsequently assembled with the device substrate, the optical device, or the external-transfer optical waveguide,

the external-transfer optical waveguide being adapted for enabling substantially adiabatic transverse-transfer of optical power between the external-transfer optical waveguide and the second optical waveguide at the optical junction region.

114. A method for fabricating an optical apparatus, comprising the steps of:

fabricating an optical device on a device substrate;

fabricating an external-transfer optical waveguide on the device substrate or on the optical device, the external-transfer optical waveguide including an optical junction region,

the optical device or the external-transfer optical waveguide being adapted for enabling transfer of optical power therebetween,

the external-transfer optical waveguide being positioned relative to the optical device so as to enable transfer of optical power therebetween,

the optical junction region of the external-transfer optical waveguide being adapted for enabling transverse-transfer of optical power between the external-transfer optical waveguide and a second optical waveguide,

the device substrate, the optical device, or the external-transfer optical waveguide being adapted for receiving and positioning the second optical waveguide relative to the optical junction region of the external-transfer optical waveguide so as to enable transverse-transfer of optical power therebetween, the second optical waveguide being provided initially as a mechanically separate component and subsequently assembled with the device substrate, the optical device, or the external-transfer optical waveguide,

the external-transfer optical waveguide being adapted for enabling mode-interference-coupled transverse-transfer of optical power between the external-transfer optical waveguide and the second optical waveguide at the optical junction region.

115. The method of claim 113 or 114 ,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling end-transfer of optical power between the optical device and the external-transfer optical waveguide,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling substantially spatial-mode-matched end-transfer of optical power between the optical device and the external-transfer optical waveguide.

116. The method of claim 113 or 114 ,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling end-transfer of optical power between the optical device and the external-transfer optical waveguide,

further including the step of forming at least a portion of the external-transfer optical waveguide by quantum-well inter-mixing of a portion of the optical device.

117. The method of claim 113 or 114 , the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling transverse-transfer of optical power between the optical device and the external-transfer optical waveguide.

118. The method of claim 113 or 114 , at least a portion of the external-transfer optical waveguide being a low-modal-index optical waveguide.

119. The method of claim 113 or 114 , at least a portion of the external-transfer optical waveguide being a high-modal-index optical waveguide.

120. The method of claim 113 or 114 , at least a portion of the external-transfer optical waveguide including a core and lower-index cladding.

121. The method of claim 120 , at least a portion of the cladding including a metal film.

122. The method of claim 113 or 114 , at least a portion of the external-transfer optical waveguide including a multi-layer waveguide structure, the multi-layer waveguide structure including at least one multi-layer reflector stack.

123. A method for fabricating an optical apparatus, comprising the steps of:

fabricating an optical device on a device substrate;

fabricating an external-transfer optical waveguide on the device substrate or on the optical device, the external-transfer optical waveguide including an optical junction region,

the optical device or the external-transfer optical waveguide being adapted for enabling transfer of optical power therebetween,

the external-transfer optical waveguide being positioned relative to the optical device so as to enable transfer of optical power therebetween,

the optical junction region of the external-transfer optical waveguide being adapted for enabling transverse-transfer of optical power between the external-transfer optical waveguide and a second optical waveguide,

the device substrate, the optical device, or the external-transfer optical waveguide being adapted for receiving and positioning the second optical waveguide relative to the optical junction region of the external-transfer optical waveguide so as to enable transverse-transfer of optical power therebetween, the second optical waveguide being provided initially as a mechanically separate component and subsequently assembled with the device substrate, the optical device, or the external-transfer optical waveguide,

the optical device or the external-transfer optical waveguide being adapted for and positioned for enabling end-transfer of optical power between the optical device and the external-transfer optical waveguide,

further including the step of etching an end face of the optical device so as to at least in part adapt the optical device for enabling end-transfer of optical power between the optical device and the external-transfer optical waveguide.

124. A method for fabricating an optical apparatus, comprising the steps of:

fabricating an optical device on a device substrate;

fabricating an external-transfer optical waveguide on the device substrate or on the optical device, the external-transfer optical waveguide including an optical junction region,

the optical device or the external-transfer optical waveguide being adapted for enabling transfer of optical power therebetween,

the external-transfer optical waveguide being positioned relative to the optical device so as to enable transfer of optical power therebetween,

the optical junction region of the external-transfer optical waveguide being adapted for enabling transverse-transfer of optical power between the external-transfer optical waveguide and a second optical waveguide,

the device substrate, the optical device, or the external-transfer optical waveguide being adapted for receiving and positioning the second optical waveguide relative to the optical junction region of the external-transfer optical waveguide so as to enable transverse-transfer of optical power therebetween, the second optical waveguide being provided initially as a mechanically separate component and subsequently assembled with the device substrate, the optical device, or the external-transfer optical waveguide,

at least a portion of the external-transfer optical waveguide being adapted for providing a portion of functionality of the optical device.

125. An optical apparatus, comprising:

multiple optical devices fabricated on a common device substrate;

multiple external-transfer optical waveguides, each fabricated on the device substrate or on the multiple optical devices; and

multiple planar transmission optical waveguides fabricated on a common waveguide substrate, the multiple planar transmission optical waveguides forming a planar optical waveguide circuit, the waveguide substrate being assembled with the device substrate,

at least one of the multiple optical devices and at least one of the multiple external-transfer optical waveguides being adapted for and positioned for optical power transfer therebetween,

at least two of the multiple external-transfer optical waveguides and at least two corresponding planar transmission optical waveguides among the multiple planar transmission optical waveguides being adapted for transverse-transfer of optical power therebetween,

assembly of the device substrate with the waveguide substrate serving to position at least two of the multiple external-transfer optical waveguides relative to the corresponding planar transmission optical waveguides for enabling transverse-transfer of optical power therebetween, thereby establishing at least two optical connections between the planar optical waveguide circuit and the multiple optical devices.

126. An optical apparatus, comprising:

multiple planar transmission optical waveguides fabricated on a common waveguide substrate, the multiple planar transmission optical waveguides forming a planar optical waveguide circuit, the planar optical waveguide circuit being adapted at multiple device locations thereof for receiving multiple corresponding optical devices; and

multiple optical devices assembled onto the waveguide substrate at corresponding device locations thereof, at least one of the multiple optical devices being formed on a corresponding device substrate, the corresponding device substrate having fabricated thereon a corresponding external-transfer optical waveguide, the optical device or the external-transfer optical waveguide being positioned for and adapted for enabling optical power transfer therebetween,

the corresponding external-transfer optical waveguide or a corresponding one of the multiple planar transmission optical waveguides being adapted for enabling transverse-transfer of optical power therebetween,

assembly of the optical device on the corresponding device substrate at a corresponding one of the multiple device locations serving to relatively position the corresponding external-transfer optical waveguide and the corresponding planar transmission optical waveguide so as to enable transverse-transfer of optical power therebetween.