Apparatus comprising a rotatable optical element

• US 20040212864A1
• Filed: 06/06/2002
• Published: 10/28/2004
• Est. Priority Date: 06/06/2002
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Marom, Dan M., Greywall, Dennis S.
• Granted Patent: US 6,984,917 B2
• Time in Patent Office: Days
• US Class Current: 359/223
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems

Abstract

A rotatable element includes a plate, a plate support, a cradle and a cradle support. The plate is coupled to the cradle via the plate support. The cradle is coupled to a surrounding frame by the cradle support. The plate and cradle are suspended over a cavity so that, in conjunction with the plate support and the cradle support, both the plate and cradle are capable of freely rotating about different axes of rotation when suitably actuated. Since the plate is capable of rotating independently of the cradle, yet also rotates when the cradle is rotated, the plate is rotatable about two axes of rotation. In some cases, the axis of rotation of the plate is perpendicular to the axis of rotation of the cradle. Since the cradle does not surround the plate, the plates of adjacent rotatable elements can be placed very close to one another (i.e., as close as about 1 micron) to provide, for example, an array of very-closely-spaced mirrors.

Claims

1. An apparatus comprising:

a cradle;

a plate, wherein said plate is rotatably coupled to said cradle along a first rotational axis; and

a frame, wherein said cradle is rotatably coupled to said frame along a second rotational axis, and wherein said cradle does not entirely surround said plate.

2. The apparatus of claim 1 wherein said plate provides an optical function.

3. The apparatus of claim 1 wherein said plate comprises a reflective surface.

4. The apparatus of claim 1 wherein said first rotational axis and said second rotational axis are substantially perpendicular.

5. The apparatus of claim 1 wherein said plate and said cradle are not concentric.

6. The apparatus of claim 1 wherein said plate, said cradle and said frame are made, at least in part, from a semiconductor.

7. The apparatus of claim 1 wherein said plate, said cradle and said frame are made, at least in part, from a material selected from the group consisting of silicon and polysilicon.

8. The apparatus of claim 1 further comprising a first electrode and a second electrode, wherein said first electrode and said second electrode:

are symmetrically disposed on opposite sides of said first rotational axis; and

are disposed close enough to said plate so that under an applied voltage of less than 200 volts, at least one of either said first electrode and said second electrode electrically interact with said plate.

9. The apparatus of claim 8 further comprising a third electrode and a fourth electrode, wherein said third electrode and said fourth electrode:

are symmetrically disposed on opposite sides of said second rotational axis; and

are disposed close enough to said cradle so that under an applied voltage of less than 200 volts, at least one of either said third electrode and said fourth electrode electrically interact with said cradle.

10. The apparatus of claim 1 wherein:

said plate and said cradle define a rotatable element; and

said apparatus comprises an array of rotatable elements.

11. The apparatus of claim 10 further comprising:

a lens, wherein said lens is optically coupled to said array of rotatable elements;

a diffraction grating, wherein said diffraction grating is optically coupled to said lens;

a lens array having a plurality of lenses, wherein each lens in said lens array is optically coupled to said diffraction grating; and

a port array having a plurality of ports, wherein each port in said port array is optically coupled to one lens in said lens array.

12. The apparatus of claim 11 wherein said port array comprises:

an input port; and

a plurality of output ports.

13. An apparatus comprising a mirror array, wherein said mirror array comprises a frame and a plurality of rotatable elements, wherein each rotatable element comprises:

a cradle, wherein said cradle is rotatably coupled to said frame along a second axis of rotation; and

a mirror, wherein said mirror is rotatably coupled to said cradle along a first axis of rotation;

wherein;

said mirror of each of two adjacent rotatable elements in said mirror array are within 15 microns of each other.

14. The apparatus of claim 13 wherein said mirror of each of two adjacent rotatable elements in said mirror array are within 10 microns of each other.

15. The apparatus of claim 13 wherein said mirror of each of two adjacent rotatable elements in said mirror array are within 5 microns of each other.

16. The apparatus of claim 13 wherein said mirror of each of two adjacent rotatable elements in said mirror array are about 1 micron from each other.

17. The apparatus of claim 13 wherein said first axis of rotation and said second axis of rotation are substantially perpendicular.

18. The apparatus of claim 13 further comprising:

a plurality of ports, wherein said plurality of ports comprises at least one input port and one output port;

a plurality of lenses, wherein;

a first lens of said plurality is optically coupled to said input port; and

a second lens of said plurality is optically coupled to said output port;

a diffraction grating, wherein said diffraction grating;

is optically coupled to said input port through said first lens;

generates a plurality of spatially-separated optical signals by diffracting a multi-wavelength signal that is received from said input port; and

is optically coupled to said output port through said second lens;

a lens, wherein said lens is optically coupled to said diffraction grating and to said mirror of each of said rotatable elements.

19. The apparatus of claim 13 further comprising:

means for spatially separating a plurality of optical signals that compose a multi-wavelength signal; and

means for coupling said plurality of optical signals to said plurality of rotatable elements, wherein at least some of said optical signals are coupled to different rotatable elements than other of said optical signals.

20. A method for forming a rotatable element, comprising:

rotatably coupling, along a first rotational axis, a plate and cradle in a first substrate, wherein said cradle does not surround said plate;

rotatably coupling, along a second rotational axis that is perpendicular to said first rotational axis, said cradle to said first substrate;

forming at least two electrodes at a first region in a second substrate;

forming at least two electrodes at a second region in said second substrate;

aligning said first substrate with said second substrate such that said plate is superposed over said two electrodes at said first region and a portion of said cradle is superposed over said two electrodes at said second region; and

attaching said first substrate to said second substrate.

21. An apparatus comprising:

a plate;

a cradle, wherein;

said cradle supports said plate at a first location and a second location;

said first location and said second location define a segment of a first rotational axis; and

said plate is rotatable about said first rotational axis;

a frame, wherein;

said frame supports said cradle at a third location and a fourth location;

said third location and said fourth location define a segment of a second rotational axis;

said cradle is rotable about said second rotational axis;

said second rotational axis is perpendicular to said first rotational axis;

and said segment of said first rotational axis and said segment of said second rotational axis do not intersect one another.

22. An apparatus comprising:

a plate, wherein said plate has a center of mass;

a cradle, wherein said cradle supports said plate for rotation about two perpendicular axes; and

a plurality of electrodes, wherein;

said electrodes are spaced apart from said plate and said cradle; and

a center of mass of said electrodes does not align with a center of mass of said plate.