Interlaced array of piano MEMs micromirrors

• US 20050180685A1
• Filed: 03/10/2005
• Published: 08/18/2005
• Est. Priority Date: 05/28/2002
• Status: Active Grant

• Current Assignee: Lumentum Operations, LLC (Lumentum Holdings Inc.)
• Original Assignee: Viavi Solutions, Inc. (Lumentum Holdings Inc.)
• Inventors: Jin, Wenlin, Keyworth, Barrie, Miller, John M., Wall, Pierre D.
• Granted Patent: US 7,167,613 B2
• Time in Patent Office: Days
• US Class Current: 385/18
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81B 3/0062 Devices moving in two or more dimensions, i.e. having special features which allow movement in more than one dimension
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• 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
• 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
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/3584 constructional details of an associated actuator having a MEMS construction, i.e. constructed using semiconductor technology such as etching MEMS per se B81B, B81C
• CPC Class Codes: Y10S 359/904 Micromirror

Abstract

A micro-electro-mechanical (MEMS) mirror device for use in an optical switch is disclosed. A “piano”-style MEMs device includes an elongated platform pivotally mounted proximate the middle thereof by a torsional hinge. The middle portion of the platform and the torsional hinge have a combined width less than the width of the rest of the platform, whereby several of these “piano” MEMs devices can be positioned adjacent each other pivotally mounted about the same axis with only a relatively small air gap therebetween. In a preferred embodiment of the present invention the spacing between electrodes is increased without effecting the fill factor of the mirrors by interlacing two sets of tilting platforms, whereby the reflecting portions of both sets of tilting platforms are adjacent one another, while the non-reflecting portions of adjacent platforms are remote from each other.

Claims

1. A micro-electro-mechanical device mounted on a substrate comprising:

an array of first pivoting members pivotally mounted on said substrate about a first lateral axis, each of said first pivoting members including a first and a second supporting region on opposite sides of said first lateral axis;

an array of second pivoting members pivotally mounted on said substrate about a second lateral axis parallel to the first lateral axis, each of said second pivoting members including a first supporting region interleaved with the first supporting regions of the first array of pivoting members between said first and second lateral axes, and a second supporting region on an opposite side of the second lateral axis; and

a first electrode beneath each of the second supporting region for pivoting the first and second pivoting members about the first axis from a rest position.

2. The device according to claim 1, further comprising first torsional hinges anchored to the substrate along the first lateral axis enabling the first array of pivoting members to pivot about the first lateral axis;

and second torsional hinges anchored to the substrate along the second lateral axis enabling the second array of pivoting members to pivot about the second lateral axis.

3. The device according to claim 2, wherein the first and second torsional hinges are resilient for restoring the pivoting members to the rest position.

4. The device according to claim 2, wherein the first supporting region is wider than the first and second torsional hinges enabling adjacent first supporting regions to be positioned in close proximity.

5. The device according to claim 1, wherein the second supporting regions of the first and second pivoting members are wider than the first supporting regions of the first and second pivoting members, respectively, for increasing electrostatic torque on the first and second pivoting members.

6. The device according to claim 2, wherein the first and second torsional hinges also enable the first and second pivoting members to rotate about longitudinal axes perpendicular to the first and second lateral axes.

7. The device according to claim 6, wherein each of the first and second torsional hinges includes a first lateral hinge anchored to the substrate, and a second longitudinal hinge anchored to the first and second pivoting members.

8. The device according to claim 7, further comprising a gimbal ring between the first lateral hinge and the second longitudinal hinge at least partially surrounding the first lateral hinge.

9. The device according to claim 6, further comprising:

an offset section extending from each of the first and second pivoting members from adjacent said first and second torsional hinges; and

a second electrode beneath each of the offset sections for pivoting the first and second pivoting members about one of the longitudinal axes.

10. The device according to claim 9, wherein the offset sections of the first pivoting members extend to adjacent an end of the second pivoting members.

11. The device according to claim 9, further comprising:

a third electrode beneath each of the first supporting regions; and

electrode control means for each of the first and second pivoting members for gradually decreasing a voltage to said first electrode to a minimum, while increasing a voltage to said second electrode to a maximum, and for gradually increasing a voltage to said third electrode, while decreasing the voltage to said second electrode to a minimum, thereby indirectly rotating the first or second pivoting member about the first or second lateral axes, respectively.

12. The device according to claim 1, further comprising shields disposed on each side of said first electrode beneath the first and second pivoting members for limiting the amount of electrical cross-talk between adjacent first electrodes, thereby enabling the first supporting regions of the first and second pivoting members to be closely packed.

13. The device according to claim 12, wherein the shields extend downwardly from an undersurface of said first and second pivoting members.

14. The device according to claim 12, wherein the shields extend upwardly from the substrate above a top surface of the first electrodes.

15. The device according to claim 12, wherein the shields extend upwardly from the substrate above a top surface of the first electrode, and downwardly from an undersurface of said pivoting member inside or outside of the upwardly extending shields.

16. The device according to claim 14, wherein each shield includes a light reflective cusp comprising a ridge with a angled reflective surface extending therefrom for redirecting light passing between adjacent first supporting regions, thereby preventing light from being reflected back.

17. The device according to claim 16, wherein the light reflective cusps beneath the first pivoting members extend beneath the first supporting regions from beneath an inner end thereof to beneath a point between the inner end and an outer free end thereof;

wherein the light reflective cusps under the second pivoting members extend beneath the first supporting regions from beneath an inner end thereof to beneath a point between the inner end and an outer free end thereof; and

wherein light passing between the first supporting regions of the first and second pivoting members will reflect off of either the light reflective cusps beneath the first pivoting members or the light reflective cusps under the second pivoting members.

18. The device according to claim 17, wherein the light reflective cusps beneath the first supporting region of the first and second pivoting members extend substantially half way between the inner end and the outer free end thereof.