Wavelength selective switch having distinct planes of operation

• US 20090220233A1
• Filed: 07/23/2008
• Published: 09/03/2009
• Est. Priority Date: 02/28/2008
• Status: Active Grant

• Current Assignee: Lumentum Operations, LLC (Lumentum Holdings Inc.)
• Original Assignee: Olympus Corporation
• Inventors: Presley, Harry W., Nagy, Michael L.
• Granted Patent: US 8,190,025 B2
• Time in Patent Office: Days
• US Class Current: 398/79
• CPC Class Codes: G02B 6/3518 the reflective optical element being an intrinsic part of a MEMS device, i.e. fabricated together with the MEMS device MEMS devices in general B81B; manufacture of MEM devices in general B81C; micromechanical devices controlling the direction of light G02B26/0833
• CPC Class Codes: G02B 6/3544 2D constellations, i.e. with switching elements and switched beams located in a plane

Abstract

A wavelength selective switch utilizing aperture-shared optics and functionally distinct planes of operation that enables high fiber port counts, such as 1×41, and multiplicative expansion, such as to 1×83 or 1×145, by utilizing elements optimized for performance in one of the functionally distinct planes of operation without affecting the other plane.

Claims

1. A wavelength selective switch for switching wavelengths from one or more optical signals, the signal comprising one or more optical wavelengths, each constituting a work piece, the wavelength selective switch comprising:

a plurality of fiber ports arranged in a fiber port array;

a plurality of optical elements operable with said plurality of fiber ports;

a dispersive element operable with said plurality of fiber ports to separate at least one optical signal into a plurality of wavelength components; and

a switching element operable with the plurality of wavelength components and controllable to guide a selected one of the plurality of wavelength components to a selected one of said plurality of fiber ports,

wherein at least one of said plurality of optical elements, said dispersive element, and said switching element affects an optical property of at least one optical signal in a first plane, and wherein said at least one of said plurality of optical elements, said dispersive element, and said switching element does not substantially affect said optical property in a second plane, said first plane being generally orthogonal to said second plane.

2. The wavelength selective switch of claim 1, wherein said at least one of said plurality of optical elements, said dispersive element, and said switching element affects a different optical property in said second plane.

3. The wavelength selective switch of claim 1, further comprising means for independently magnifying the one or more optical signals in said first and second generally orthogonal planes, wherein such magnification in said first and second generally orthogonal planes enables optimization of performance of an element selected from the group consisting of at least one of said plurality of optical elements, said dispersive element, and said switching element in at least one of said first and second generally orthogonal planes.

4. The wavelength selective switch of claim 1, further comprising means for independently magnifying the one or more optical signals in said first and second generally orthogonal planes, wherein such magnification in said first and second generally orthogonal plane reduces the total size of said wavelength selective switch.

5. The wavelength selective switch of claim 1, wherein said fiber port array further comprises means for modifying the size of an optical beam in at least one of said first and second generally orthogonal planes, wherein said means for modifying provides an additional degree of design freedom by relaxing a performance requirement of at least one element selected from the group consisting of said plurality of optical elements, said dispersive element, and said switching element.

6. The wavelength selective switch of claim 1, further comprising means for positioning at least one of said plurality of optical elements, said dispersive element, said switching element in one of said first and second generally orthogonal planes, wherein said means for positioning reduces a design constraint by relaxing performance requirement of an element selected from the group consisting of at least one of said plurality of optical elements, said dispersive element, and said switching element.

7. The wavelength selective switch of claim 6, further comprising means for positioning at least one of said dispersive element, said switching element, and said fiber port array proximate a location corresponding to at least one focal point of at least one of said plurality of optical elements in at least one of said first and second generally orthogonal planes.

8. The wavelength selective switch of claim 1, further comprising at least one optical element, performing in a telescopic manner, disposed between said fiber port array and said dispersive element.

9. The wavelength selective switch of claim 8, wherein said at least one optical element, performing in a telescopic manner reduces a design constraint of at least one of said plurality of optical elements, said dispersive element, and said switching element.

10. The wavelength selective switch of claim 8, wherein said at least one optical element, performing in a telescopic manner increases a beam size of the optical signal proximate said dispersive element, thereby reducing a design constraint of said dispersive element.

11. The wavelength selective switch of claim 8, wherein said at least one optical element, performing in a telescopic manner operates on the one or more optical signals in each of said first and second generally orthogonal planes.

12. The wavelength selective switch of claim 1, wherein said at least one of said plurality of optical elements, said dispersive element, or said switching element operates on the one or more optical signals in one of said first and second generally orthogonal planes and substantially passive in the other plane.

13. The wavelength selective switch of claim 12, wherein said at least one of said plurality of optical elements, said dispersive element, or said switching element performs in an anamorphic manner.

14. The wavelength selective switch of claim 1, wherein said dispersive element, said switching element, and said fiber port array are disposed proximate a local beam waist of the one or more optical signals, thereby reducing a design constraint of at least one of said plurality of optical elements, said dispersive element, and said switching element.

15. The wavelength selective switch of claim 1, wherein the one or more optical signals propagates generally parallel to an optical axis in a telecentric fashion proximate said dispersive element in one of said first and second generally orthogonal planes.

16. The wavelength selective switch of claim 1, wherein the one or more optical signals propagates generally parallel to an optical axis in a telecentric fashion between said dispersive element and said switching element in one of said first and second generally orthogonal planes.

17. The wavelength selective switch of claim 1, wherein said plurality of optical elements comprises at least one spherical lens and at least one cylindrical lens.

18. The wavelength selective switch of claim 17, wherein said at least one spherical lens comprises a first, a second and a third spherical lens and wherein said at least one cylindrical lens comprises a first, a second and a third cylindrical lens.

19. The wavelength selective switch of claim 18, wherein said third spherical lens is positioned between said dispersive element and said switching element, and wherein said position is substantially at one focal length of said third spherical lens from said dispersive element and said switching element.

20. The wavelength selective switch of claim 18, wherein said third spherical lens simultaneously creates convergent optical signals in one of said first and second generally orthogonal planes and telecentric optical signals in the other.

21. The wavelength selective switch of claim 18, wherein said first, said second and said third cylindrical lens are disposed between said fiber port array and said dispersive element.

22. The wavelength selective switch of claim 18, wherein said third cylindrical lens is positioned between said fiber port array and said dispersive element, wherein said position is substantially one focal length of said third cylindrical lens from said dispersive element.

23. The wavelength selective switch of claim 18, wherein said third cylindrical lens is operable in one of said first and second generally orthogonal planes and substantially passive in the other.

24. The wavelength selective switch of claim 18, wherein said third cylindrical lens comprises a focal length substantially equal the sum of substantially one focal length of said first cylindrical lens and substantially one focal length of said second cylindrical lens.

25. The wavelength selective switch of claim 18, wherein said first and said second cylindrical lenses produce one or more optical signals that propagate generally parallel to an optical axis in a telecentric fashion after said first and said second cylindrical lenses in one of said first and said second generally orthogonal planes.

26. The wavelength selective switch of claim 18, wherein said first and said second cylindrical lens design parameters enable said third spherical lens to produce convergent optical signals proximate said switching element in at least one of said first and said second generally orthogonal planes.

27. The wavelength selective switch of claim 18, wherein said first and said second cylindrical lenses are operable in one of said first and said second generally orthogonal planes and substantially passive in the other.

28. The wavelength selective switch of claim 18, wherein said first and said second spherical lenses are disposed between said fiber port array and said first cylindrical lens.

29. The wavelength selective switch of claim 24, wherein said focal length of said first spherical lens and said focal length of said second spherical lens are both optimized for the purpose of reducing a tilt requirement of said switching element necessary for directing the one or more optical signals between said fiber ports.

30. The wavelength selective switch of claim 24, wherein said focal length of said first spherical lens is derived based on balancing a tilt requirement of said switching element and a height to width aspect ratio of said switching element.

31. The wavelength selective switch of claim 1, wherein said switching element further comprises a height to width aspect ratio of 10 or less.

32. The wavelength selective switch of claim 18, wherein said first cylindrical lens and said second cylindrical lens are positioned proximate each side of a local beam waist of the one or more optical signals, and wherein said positioning from said beam waist is a focal length of each said cylindrical lens in one of said first and said second generally orthogonal planes and not the other.

33. The wavelength selective switch of claim 1, further comprising a beam steering element operable to steer the one or more optical signals within said plurality of fiber ports arranged in a fiber port array.

34. The wavelength selective switch of claim 33, wherein said beam steering element further comprises one or more facets of an integrated monolithic element.

35. The wavelength selective switch of claim 34, wherein said one or more facets is operable to converge a common wavelength from said plurality of fiber ports on to a specific wavelength-associated switching element.

36. The wavelength selective switch of claim 1, wherein said fiber port array comprises a two-dimensional fiber port array having a plurality of columns of fiber ports, and further comprising a beam steering element operable to steer the one or more optical signals within one said column of fiber ports of said plurality of columns of fiber ports.

37. The wavelength selective switch of claim 36, wherein said beam steering element further comprises one or more facets of an integrated monolithic element, at least one facet of said one or more facets is operable to steer the one or more optical signals within said column of fiber ports of said plurality of columns of fiber ports.

38. The wavelength selective switch of claim 33, wherein said beam steering element is selected from a group consisting of optical prisms, reflectors, diffractive elements, holographic elements, liquid crystals, liquid crystals on silicon, and combinations thereof.

39. The wavelength selective switch of claim 1, wherein said switching element is an array of MEMS mirrors.

40. The wavelength selective switch of claim 1, wherein said plurality of optical elements further comprises at least one quarter wave plate included in said plurality of optical elements to reduce polarization dependent loss.

41. The wavelength selective switch of claim 1, further comprising an optical power monitor.

42. The wavelength selective switch of claim 33, wherein said beam steering element is operable to converge a common wavelength from said plurality of fiber ports on to a specific wavelength-associated switching element.

43. The wavelength selective switch of claim 1, wherein said optical elements further comprise at least one beam steering element configured within said plurality of optical elements and wherein said plurality of fiber ports is further arranged in a two dimensional fiber port array, and wherein the optical signal reflecting from a dual axis switching element is steered by said at least one beam steering element to one of said plurality of fiber ports.

44. The wavelength selective switch of claim 43, wherein said two dimensional fiber port array is further arranged in a plurality of columns of fiber ports.

45. The wavelength selective switch of claim 43, wherein said beam steering element is operable to converge a common wavelength from one or more fiber ports of said plurality of fiber ports on to a specific wavelength-associated switching element.

46. The wavelength selective switch of claim 45, wherein said dual axis switching element is operable in a first axis to switch at least one wavelength from said specific wavelength-associated switching element to one select fiber port of said plurality of fiber ports.

47. The wavelength selective switch of claim 45, wherein said dual axis switching element is operable in a second axis to control power equalization of the one or more optical signals.

48. The wavelength selective switch of claim 1, wherein the same wavelengths from the one or more optical signals overlap one another to share an optical aperture of at least one of said plurality of optical elements, without cross talk between the same wavelengths.

49. The wavelength selective switch of claim 40, wherein said at least one quarter wave plate is combined with a lens or a mirror, to form one of said optical elements.

50. The wavelength selective switch of claim 40, wherein said at least one quarter wave plate is used as a protective transparent cover for said switching element.

51. A wavelength selective switch for switching wavelengths from one or more optical signals, the signal comprising one or more optical wavelengths, each constituting a work piece, the wavelength selective switch comprising:

a plurality of fiber ports arranged in a fiber port array;

a plurality of optical elements operable with said plurality of fiber ports;

at least one beam steering element operable to steer the one or more optical signals within said plurality of fiber ports arranged in said fiber port array;

a dispersive element operable with said plurality of fiber ports to separate at least one optical signal into a plurality of wavelength components; and

a switching element operable with the plurality of wavelength components and controllable to guide a selected one of the plurality of wavelength components to a selected one of said plurality of fiber ports,

wherein at least one of said plurality of optical elements, said beam steering element, said dispersive element, and said switching element affects an optical property of at least one optical signal in a first plane, and wherein said at least one of said plurality of optical elements, said beam steering element, said dispersive element, and said switching element does not substantially affect said optical property in a second plane, said first plane being generally orthogonal to said second plane.

52. The wavelength selective switch of claim 52, wherein said plurality of optical elements comprises at least one said optical element performing in a telescopic manner.

53. A wavelength selective switch for switching wavelengths from one or more optical signals, the signal comprising one or more optical wavelengths, each constituting a work piece, the wavelength selective switch comprising:

a plurality of fiber ports arranged in a two dimensional fiber port array having a plurality of columns of fiber ports;

a plurality of optical elements operable with said plurality of fiber ports;

a dispersive element operable with said plurality of fiber ports to separate at least one optical signal into a plurality of wavelength components;

a switching element operable with the plurality of wavelength components and controllable to guide a selected one of the plurality of wavelength components to a selected one of said plurality of fiber ports; and

at least one beam steering element operable to steer the one or more optical signals from said plurality of fiber ports to said switching element, and from said switching element to said plurality of fiber ports;

wherein at least one of said plurality of optical elements, said dispersive element, said beam steering element, and said switching element affects an optical property of at least one optical signal in a first plane, and wherein said at least one of said plurality of optical elements, said dispersive element, said beam steering element, and said switching element does not affect said optical property in a second plane, said first plane being generally orthogonal to said second plane.

54. The wavelength selective switch of claim 53, wherein said switching element further comprises an array of mirrors, wherein each mirror in said array of mirrors is configured to tilt about two axes, one axis in said first plane and the other axis in said second plane.

55. The wavelength selective switch of claim 53, wherein said plurality of optical elements comprises at least one said optical element performing in a telescopic manner.

56. The wavelength selective switch of claim 53, wherein said beam steering element further comprises one or more facets of an integrated monolithic element, at least one facet of said one or more facets is operable to steer the one or more optical signals within said fiber ports of said plurality of fiber ports.

57. The wavelength selective switch of claim 54, wherein said switching element, said beam steering element, and said two dimensional fiber port array are configured to selectively steer at least one wavelength from a column of fiber ports of said plurality of fiber ports to a different column of fiber ports of said plurality of fiber ports.

58. A method for optimizing optical switch performance comprising the steps of:

providing a plurality of fiber ports arranged in a fiber port array, a plurality of optical elements operable with said plurality of fiber ports, a dispersive element operable with said plurality of fiber ports to separate at least one optical signal into a plurality of wavelength components, and a switching element operable with the plurality of wavelength components and controllable to guide a selected one of the plurality of wavelength components to a selected one of said plurality of fiber ports, wherein at least one of said plurality of optical elements, said dispersive element, and said switching element affects an optical property of at least one optical signal in a first plane, and wherein said at least one of said plurality of optical elements, said dispersive element, and said switching element does not affect said optical property in a second plane, said first plane being generally orthogonal to said second plane; and

,

positioning at least one of said dispersive element, said switching element, and said fiber port array at a focal point of at least one of said plurality of optical elements in at least one plane of said first and said second generally orthogonal planes.

59. The method of claim 58, wherein said positioning of said at least one of said dispersive element, said switching element, and said fiber port array further comprises the step of reducing a design constraint of at least one of said plurality of optical elements, said dispersive element, and said switching element.

60. The method of claim 58, further comprising the step of providing at least one optical element of said plurality of optical elements performing in a telescopic manner, wherein said optical element performing in a telescopic manner further comprises the step of reducing a design constraint of at least one of said plurality of optical elements, said dispersive element, and said switching element.

61. The method of claim 58, further comprising the step of producing one or more optical signals that propagate generally parallel to an optical axis of said switch in a telecentric fashion in at least one of said first and said second generally orthogonal planes.

62. The method of claim 58, further comprising the step of producing one or more optical signals that propagate generally parallel to each other in a telecentric fashion as the one or more optical signals approach said switching element in one of said first and said second generally orthogonal planes.

63. The method of claim 58, further comprising the step of creating convergent optical signals in at least one of said first and said second generally orthogonal planes and creating telecentric beams in the other.

64. The method of claim 58, further comprising the step of independently magnifying the one or more optical signals in at least one of said first and second generally orthogonal planes, wherein said independent magnification in at least one of said first and second generally orthogonal planes enables optimization of performance of an element selected from the group consisting of at least one of said plurality of optical elements, said dispersive element, and said switching element in at least one of said first and second generally orthogonal planes.

65. The method of claim 58, further comprising the step of independently magnifying the one or more optical signals in at least one of said two generally orthogonal planes, wherein said magnifying reduces a design constraint of at least one element selected from the group consisting of said plurality of optical elements, said dispersive element, and said switching element.

66. The method of claim 58, wherein said step of positioning at least one of said plurality of optical elements, said dispersive element, said switching element in at least one of said two generally orthogonal planes, provides an additional degree of design freedom by relaxing a performance requirement on an element selected from the group consisting of at least one of said plurality of optical elements, said dispersive element, and said switching element.

67. The method of claim 58, wherein said step of positioning at least one of said dispersive element, said switching element, and said fiber port array proximate a location corresponding to at least one focal point of at least one of said plurality of optical elements in both of said two generally orthogonal planes provides an additional degree of design freedom by relaxing a performance requirement of an element selected from the group consisting of at least one of said plurality of optical elements, said dispersive element, and said switching element.

68. The method of claim 58, further comprising the step of increasing a size of the optical signal proximate said dispersive element, thereby relaxing a performance requirement on said dispersive element.

69. The method of claim 60, further comprising the step of minimizing a focal length of said at least one optical element performing in a telescopic manner, wherein said minimizing reduces a tilt requirement of said switching element necessary for directing the one or more optical signals between said fiber ports.

70. A method for increasing an optical switch fiber port count comprising the steps of:

providing a plurality of fiber ports arranged in a two dimensional fiber port array, a plurality of optical elements operable with said plurality of fiber ports, a dispersive element operable with said plurality of fiber ports to separate at least one optical signal into a plurality of wavelength components, a switching element operable with the plurality of wavelength components and controllable to guide a selected one of the plurality of wavelength components to a selected one of said plurality of fiber ports, and at least one beam steering element operable to steer the one or more optical signals within said plurality of fiber ports, wherein at least one of said plurality of optical elements, said dispersive element, said beam steering element, and said switching element affects an optical property of at least one optical signal in a first plane, and wherein said at least one of said plurality of optical elements, said dispersive element, said beam steering element, and said switching element does not affect said optical property in a second plane, said first plane being generally orthogonal to said second plane; and

,

positioning at least one of said dispersive element, said switching element, said beam steering element, and said two dimensional fiber port array at a focal point of at least one of said plurality of optical elements in at least one plane of said first and said second generally orthogonal planes.

71. The method of claim 70, further comprising the step of providing at least one optical element of said plurality of optical elements performing in a telescopic manner, wherein said optical element performing in a telescopic manner further comprises the step of reducing a design constraint of at least one of said plurality of optical elements, said dispersive element, said beam steering element, and said switching element.

72. The method of claim 70, wherein said switching element further comprises an array of mirrors, wherein each mirror in said array of mirrors is configured to tilt about two axes, one axis in said first plane and the other axis in said second plane of said first and said second generally orthogonal planes.

73. The method of claim 70, further comprising the step of producing optical signals that propagate generally parallel to an optical axis of said switch in a telecentric fashion in at least one of said first and said second generally orthogonal planes.

74. The method of claim 70, further comprising the step of producing optical signals that propagate generally parallel to each other in a telecentric fashion as the one or more optical signals approach said switching element in one of said first and said second generally orthogonal planes.

75. The method of claim 70, further comprising the step of creating convergent optical signals in at least one of said first and said second generally orthogonal planes and creating telecentric beams in the other.

76. The method of claim 70, further comprising the step of independently magnifying the one or more optical signals in at least one of said first and second generally orthogonal planes, wherein said independent magnification in at least one of said first and second generally orthogonal planes enables optimization of performance of an element selected from the group consisting of at least one of said plurality of optical elements, said dispersive element, said beam steering element, and said switching element in at least one of said first and second generally orthogonal planes.

77. The method of claim 70, further comprising the step of independently magnifying the one or more optical signals in at least one of said two generally orthogonal planes, wherein said magnifying reduces a design constraint of at least one element selected from the group consisting of said plurality of optical elements, said dispersive element, said beam steering element, and said switching element.

78. The method of claim 70, wherein said positioning of said plurality of optical elements, said dispersive element, said beam steering element, said switching element in at least one of said two generally orthogonal planes, further comprises the step of reducing a design constraint of an element selected from the group consisting of at least one of said plurality of optical elements, said dispersive element, said beam steering element, and said switching element.

79. The method of claim 70, further comprising the step of positioning at least one of said dispersive element, said beam steering element, said switching element, and said fiber port array proximate a location corresponding to at least one focal point of at least one of said plurality of optical elements in at least one of said two generally orthogonal planes, wherein said positioning reduces a design constraint of an element selected from the group consisting of at least one of said plurality of optical elements, said dispersive element, said beam steering element, and said switching element.

80. The method of claim 70, further comprising the step of increasing a size of the one or more optical signals proximate said dispersive element, thereby relaxing a performance requirement on said dispersive element.

81. The method of claim 71, further comprising the step of minimizing a focal length of said at least one optical element performing in a telescopic manner, wherein said minimizing reduces a tilt requirement of said switching element necessary for directing the one or more optical signals between said fiber ports.