Wavelength-selective 1×N2 switches with two-dimensional input/output fiber arrays

• US 7,336,867 B2
• Filed: 05/30/2006
• Issued: 02/26/2008
• Est. Priority Date: 08/08/2002
• Status: Expired due to Term

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Tsai, Jui-Che, Wu, Ming-Chiang
• Primary Examiner(s): Pak; Sung
• Application Number:
  US11/444,146
• Publication Number:
  US 20060291773A1
• Time in Patent Office: 637 Days
• Field of Search: None
• US Class Current: 385/18
• CPC Class Codes: G02B 6/2931 Diffractive element operating in reflection
• CPC Class Codes: G02B 6/29311 Diffractive element operating in transmission
• CPC Class Codes: G02B 6/29313 characterised by means for controlling the position or direction of light incident to or leaving the diffractive element, e.g. for varying the wavelength response switching G02B6/35
• CPC Class Codes: G02B 6/29383 Adding and dropping
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• 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 6/3558 1xN switch, i.e. one input and a selectable single output of N possible outputs
• CPC Class Codes: G02B 6/356 in an optical cross-connect device, e.g. routing and switching aspects of interconnecting different paths propagating different wavelengths to (re)configure the various input and output links switching polarized beams G02B6/3594; power equalizers G02B6/356 and G02B6/3594; path selecting means H04Q11/0001

Abstract

A 1×N² wavelength selective switch (WSS) configuration in which switch elements are configured in a way that enables the input or output fibers to be arranged in a two-dimensional (2D) array. By employing 2D arrays of input/output channels, the channel count is increased from N to N² for wavelength selective switches. In one embodiment, in which the components are arranged as a 2- ƒ imaging system, a one-dimensional (1D) array of mirrors is configured such that each mirror has a dual scanning axis (i.e., each mirror can be scanned in X and Y directions). In another embodiment, in which the components are arranged as a 4- ƒ imaging system, two 1D arrays of mirrors are configured with orthogonal scanning directions. In both embodiments, the number of ports is increased from N to N².

Claims

1. A method of optically switching multiple wavelengths to and from a two-dimensional array of optical ports, comprising:

controlling the single-axis angular position of rotating micromirror elements within a first and second micromirror array;

receiving an optical beam containing multiple wavelengths from a two-dimensional array of optical ports;

dispersing wavelength components of said optical beam which reflect from a wavelength dispersive element;

reflecting said wavelength components from micromirror elements of the first micromirror array in a first plane toward the second micromirror array in a second plane;

reflecting said wavelength components from micromirror elements in said second micromirror array in the second plane toward said first micromirror array;

reflecting said wavelength components from micromirror elements in said first micromirror array toward said wavelength dispersive element; and

directing an optical beam containing said wavelength components from said wavelength dispersive element to said two-dimensional array of optical ports.

2. A method as recited in claim 1, wherein said wavelength dispersive element comprises a diffraction grating.

3. A method as recited in claim 1, wherein said diffraction grating is disposed proximal the path between said first and second micromirror arrays.

4. A method as recited in claim 1, wherein micromirrors within said micromirror array comprises micro-electro-mechanical systems (MEMS) micromirrors.

5. A method as recited in claim 1, further comprising at least one imaging component configured for positioning said optical beam onto said first array, said second array, or a combination of said first and second array of actuated mirrors.

6. A method as recited in claim 5, wherein said imaging component comprises at least one lens.

7. A method as recited in claim 1, wherein said first plane and said second plane are configured in a 4-ƒ

confocal arrangement.

8. A method as recited in claim 1, wherein said diffraction grating lies equal distance between said first micromirror array and said second micromirror array.

9. A method as recited in claim 8:

wherein at least one imaging component comprises at least one lens; and

wherein said at least one lens is disposed between said diffraction grating and said first micromirror array and said second micromirror array.

10. A method as recited in claim 1, wherein micromirrors in said second micromirror array are configured for rotating in a single axis which is orthogonal to the axis of rotation for said first micromirror array.

11. A method of optically switching multiple wavelengths to and from a two-dimensional array of optical ports, comprising:

controlling the single-axis angular position of rotating micromirror elements within a first and second micromirror array;

receiving an optical beam containing multiple wavelengths from a two-dimensional array of optical ports;

dispersing wavelength components of said optical beam which reflect from a wavelength dispersive element;

focusing said wavelength components received from said wavelength dispersive element through a first imaging component to a first plane;

rotating micromirror elements within a first micromirror array located on said first plane, each micromirror in said first micromirror array configured for rotation about a single axis;

reflecting said wavelength components from said micromirror elements to said first imaging component assembly;

directing said wavelength components from said first imaging component assembly to a second imaging component;

focusing said wavelength components through said second imaging component to a second plane;

rotating micromirror elements within a second micromirror array located on said second plane, each micromirror in said second micromirror array configured for rotation about a single axis in response to said micromirror deflection signal;

reflecting said wavelength components from said micromirror elements to said second imaging component;

directing said wavelength components through said second imaging component to said first imaging component;

focusing said wavelength components through said first imaging component to said first micromirror array in said first plane;

reflecting said wavelength components from said first micromirror array back to said first imaging component;

directing said wavelength components through said first imaging component to said wavelength dispersive element; and

directing an optical beam containing said wavelength components from said wavelength dispersive element to said two-dimensional array of optical ports.

12. A method as recited in claim 11, wherein said wavelength dispersive element comprises a diffraction grating.

13. A method as recited in claim 11, wherein said first and/or second imaging components comprise at least one lens.

14. A method as recited in claim 11, wherein the single axis rotation of micromirrors in said second micromirror array is orthogonal to the rotation of micromirrors in said first micromirror array.

15. A method as recited in claim 11, wherein said first plane and said second plane are positioned in a 4-ƒ

confocal arrangement.

16. A method as recited in claim 11, wherein said wavelength dispersive element lies equal distance between said first micromirror array and said second micromirror array.

17. A wavelength selective optical switch, comprising:

a two-dimensional array of optical ports configured for communicating optical beams containing multiple wavelength components, and having a plurality of ports including a first and second port;

a wavelength dispersive element configured for separating at least one wavelength component in said optical beams from at least one other wavelength component in said optical beams;

a first array of single-axis actuated mirrors; and

a second array of single-axis actuated mirrors;

wherein said first array receives dispersed optical beams from said wavelength dispersive element and directs them onto said second array, and receives dispersed optical beams from said second array back onto said wavelength dispersive element;

wherein said first and second arrays of actuated mirrors are configured for switching the wavelength components of said optical beam from said first port to a second port within said two-dimensional array of optical ports.

18. A wavelength selective optical switch as recited in claim 17, wherein said second array of mirrors is configured with a scanning direction that is orthogonal to said first array of mirrors.

19. A wavelength selective optical switch as recited in claim 17, wherein said first and second array of mirrors are configured in a 4- ƒ

confocal arrangement centered on said wavelength dispersive element.

20. A wavelength selective optical switch as recited in claim 17, further comprising at least one imaging component configured for positioning said optical beam onto said first array, or said second array, or a combination of said first and second arrays of actuated mirrors.

21. A wavelength selective optical switch as recited in claim 17, further comprising means for collimating optical beams in said optical switch.

22. A wavelength selective optical switch as recited in claim 21, wherein said means for collimating optical beams in said optical switch comprises a monolithic two-dimensional collimator array.

23. A wavelength selective optical switch as recited in claim 17, wherein said wavelength selective optical switch is incorporated within an N×

N fully non-blocking wave length-selective optical crossconnect.

24. A wavelength selective optical switch as recited in claim 17, wherein said wavelength selective optical switch is incorporated within an optical network.

25. A wavelength selective optical switch, comprising:

a two-dimensional array of optical ports configured for communicating optical beams containing multiple wavelength components, and having a plurality of ports including a first and second port;

a wavelength dispersive element configured for separating at least one wavelength component in said optical beams from at least one other wavelength component in said optical beams;

a first array of single-axis actuated mirrors;

a second array of single-axis actuated mirrors; and

said first and second arrays of mirrors are configured in a 4-ƒ

confocal arrangement centered on said wavelength dispersive element;

wherein said first and second arrays of actuated mirrors are configured for switching the wavelength components of said optical beam from said first port to a second port within said two-dimensional array of optical ports.