Method and structure for a slug caterpillar piezoelectric latching reflective optical relay

• US 6,765,161 B1
• Filed: 04/14/2003
• Issued: 07/20/2004
• Est. Priority Date: 04/14/2003
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Fong, Arthur, Wong, Marvin Glenn
• Primary Examiner(s): Friedhofer, Michael A.
• Application Number:
  US10/412,910
• Time in Patent Office: 463 Days
• Field of Search: 200/182, 200/187-189, 200/209-214, 200/216, 200/219, 200/223-236, 310/328, 310/331, 310/348, 310/363, 335/4, 335/47, 335/78, 385/19
• US Class Current: 200/182
• CPC Class Codes: G02B 26/004 based on a displacement or a deformation of a fluid
• CPC Class Codes: G02B 6/3514 the reflective optical element moving along a line so as to translate into and out of the beam path, i.e. across the beam path
• CPC Class Codes: G02B 6/3538 based on displacement or deformation of a liquid controlling the intensity of light by displacement or deformation of a fluid in general G02B26/004; fluid-filled lens of variable focal length G02B3/14
• CPC Class Codes: G02B 6/3548 1xN switch, i.e. one input and a selectable single output of N possible outputs
• CPC Class Codes: G02B 6/3578 Piezoelectric force piezoelectric forces controlling reflecting elements in general G02B26/0858; piezo-optic devices G02F1/0131
• CPC Class Codes: G02B 6/358 Latching of the moving element, i.e. maintaining or holding the moving element in place once operation has been performed; includes a mechanically bistable system

Abstract

A method and structure for a reflective optical switch. According to the structure, a chamber is housed within a solid material. A plurality of piezoelectric elements within the chamber are coupled to the solid material. A slug within the chamber is operable to be coupled to one or more of the plurality of piezoelectric elements. A liquid metal within the chamber is coupled to the slug. One or more signals of a first one or more optical waveguides coupled to the chamber are operable to be coupled to a second one or more optical waveguides coupled to the chamber. According to the method, one or more of the plurality of piezoelectric elements are actuated, with the actuation of the one or more piezoelectric elements causing the slug coupled to the one or more piezoelectric elements to move from a first number of wetting pads to a second number of wetting pads wherein the first number of wetting pads and the second number of wetting pads are wetted by the liquid metal. The movement of the slug from the first number of wetting pads to the second number of wetting pads breaks a liquid metal surface tension between the slug and the first number of wetting pads and establishes a coupling between the slug and the second number of wetting pads. The movement of the slug and the presence of the liquid metal creates a reflective surface operable to route the one or more signals from the first one or more optical waveguides to the second one or more optical waveguides.

Claims

1. A structure for a reflective optical switch, comprising:

a gas-filled chamber housed within a solid material;

a first one or more optical waveguides coupled to the gas-filled chamber wherein the first one or more optical waveguides are parallel to a longitudinal axis of the gas-filled chamber;

a second one or more optical waveguides coupled to the gas-filled chamber wherein the second one or more optical waveguides are not parallel to the first one or more optical waveguides;

a plurality of piezoelectric elements of the gas-filled chamber, coupled to the solid material;

a slug within the gas-filled chamber coupled to one or more of the plurality of piezoelectric elements, said slug operable to move along the longitudinal axis of the gas-filled chamber; and

a liquid metal within the gas-filled chamber, said liquid metal operable to be coupled to the slug wherein the coupling of the liquid metal to the slug and gas-filled chamber is operable to create an optically reflective surface.

2. The structure of claim 1, wherein prior to being coupled to the solid material, the plurality of piezoelectric elements are coupled to a conductive adhesive.

3. The structure of claim 1, wherein the first one or more optical waveguides and the second one or more optical waveguides are coupled to the solid material using an encapsulant.

4. The structure of claim 1, wherein the plurality of piezoelectric elements are perpendicular to the longitudinal axis of the gas-filled chamber.

5. The structure of claim 1, wherein the chamber is filled with an inert gas.

6. The structure of claim 1, wherein a gas of the gas-filled chamber is nitrogen.

7. The structure of claim 1, wherein the liquid metal is mercury.

8. The structure of claim 1, wherein the slug stays within a volume of the liquid metal during an actuation of one or more of the plurality of piezoelectric elements.

9. The structure of claim 1, wherein the slug is tapered at one or more ends.

10. The structure of claim 1, wherein the plurality of piezoelectric elements are segmented.

11. The structure of claim 1, wherein the gas-filled chamber may be composed of one or more of glass, ceramic, composite material and ceramic-coated material.

12. The structure of claim 1, wherein the plurality of piezoelectric elements are coupled to a common ground.

13. The structure of claim 1, wherein the plurality of piezoelectric elements have a triangular notch removed on a side closest to the first one or more optical waveguides.

14. The structure of claim 1, further comprising one or more vias coupled to the gas-filled chamber, wherein the one or more vias are coupled to a channel.

15. The structure of claim 14, wherein the channel is operable to equalize a first pressure on a first end of the slug and a second pressure on a second end of the slug.

16. The structure of claim 14, wherein the one or more vias are oriented so that the plurality of piezoelectric elements are located between a first via of the one or more vias and a second via of the one or more vias.

17. The structure of claim 1, wherein the chamber further comprises a plurality of wetting pads, said plurality of wetting pads being wettable by the liquid metal.

18. The structure of claim 17, wherein the plurality of wetting pads are coupled to the slug and the liquid metal.

19. The structure of claim 17, wherein the plurality of wetting pads are part of a single piece of material.

20. The structure of claim 17, wherein a face of the plurality of wetting pads forms a first angle with the first one or more optical waveguides that is substantially the same as a second angle with the second one or more optical waveguides.

21. The structure of claim 17, wherein the plurality of wetting pads further comprise an upper ridge and a said lower ridge, said upper ridge and lower ridge operable to create a planar reflective surface using the liquid metal and the slug.

22. The structure of claim 17, wherein the plurality of wetting pads and ridges are formed on a transparent support structure.

23. The structure of claim 17, wherein the slug, the liquid metal and the plurality of wetting pads are operable to create a reflective surface that reflects an optical signal from one or more of the first one or more optical waveguides to one or more of the second one or more optical waveguides.

25. The structure of claim 23, wherein the cap layer, the optical layer, the piezoelectric layer, and the substrate layer are composed of one or more of glass, ceramic, composite material and ceramic-coated material.

26. The structure of claim 23, wherein the substrate layer further comprises a plurality of circuit traces and a plurality of pads operable to route one or more signals generated by actuation of one or more of the plurality of piezoelectric elements.

27. The structure of claim 23, wherein the chamber is filled with an inert gas.

28. The structure of claim 23, wherein the liquid metal is mercury.

29. The structure of claim 23, wherein the slug is tapered at one or more ends.

30. The structure of claim 23, wherein the channel is operable to equalize a first pressure on a first end of the slug and a second pressure on a second end of the slug.

31. The structure of claim 23, wherein the one or more vias are oriented so that the plurality of piezoelectric elements are located between a first via of the one or more vias and a second via of the one or more vias.

33. The method of claim 31, wherein the slug is wetted by the liquid metal.

34. The method of claim 31, wherein the coupling between the slug and the second number of wetting pads is due to a plurality of surface tension forces caused by the liquid metal.

35. The method of claim 31, wherein one or more of the first number of wetting pads and one or more of the second number of wetting pads are the same.

36. The method of claim 31, wherein actuating one or more of the plurality of piezoelectric elements is operable to reduce a velocity of the slug.

37. The method of claim 31, wherein the plurality of piezoelectric elements are actuated in an adjacent manner.

24. A structure for a reflective optical switch, comprising:

a cap layer comprising a channel;

a substrate layer coupled to the cap layer, said substrate layer comprising one or more vias coupled to the channel;

an optical layer coupled to the substrate layer, said optical layer comprising a chamber coupled to the one or more vias wherein the chamber comprises a slug, liquid metal coupled to the slug, and a plurality of wetting pads operable to be coupled to the slug and coupled to the liquid metal;

a piezoelectric layer coupled to the optical layer, said piezoelectric layer comprising a plurality of piezoelectric elements wherein the plurality of piezoelectric elements are operable to contact the slug;

a first one or more optical waveguides coupled to the cap layer, substrate layer and coupled to the chamber; and

a second one or more optical waveguides coupled to the chamber, wherein the second one or more optical waveguides are not parallel to the first one or more optical waveguides, wherein the slug, the liquid metal and the plurality of wetting pads are operable to create a reflective surface that reflects an optical signal from one or more of the first one or more optical waveguides to one or more of the second one or more optical waveguides.

32. A method for optical switching of one or more optical signals using a liquid metal reflective optical switch, comprising:

actuating one or more of a plurality of piezoelectric elements;

the actuation of the one or more piezoelectric elements causing a slug coupled to the one or more piezoelectric elements to move from a first number of wetting pads to a second number of wetting pads wherein the first number of wetting pads and the second number of wetting pads are wetted by a liquid metal;

the movement of the slug from the first number of wetting pads to the second number of wetting pads breaking a liquid metal surface tension between the slug and the first number of wetting pads and establishing a coupling between the slug and the second number of wetting pads; and

the coupling between the slug and the second number of wetting pads creating a liquid metal reflective surface operable to reflect an optical signal of the one or more optical signals from a first one or more optical waveguides to a second one or more optical waveguides.