Light activated optical switch that includes a piezoelectric element with layers of piezoelectric material having different piezoelectric characteristics

1. A method for operating an optical switch, the method comprising:

applying a signal light to an optical switch that comprises a piezoelectric element, the piezoelectric element comprising at least two layers of piezoelectric material that have different piezoelectric characteristics; and

applying an activation light to the piezoelectric element to change the state of the optical switch,

said piezoelectric element being activated by an electrical field of said activation light, without said activation light impinging on said piezoelectric element.

2. The method of claim 1 wherein said applying the activation light to the piezoelectric element causes the shape of the piezoelectric element to change such that the signal light is not able to pass through the optical switch.

3. The method of claim 2 wherein the change in the shape of the piezoelectric element causes a change in a dimension of a signal channel of the optical switch.

4. A method for operating an optical switch, the method comprising:

applying a signal light to an optical switch that comprises a piezoelectric element, the piezoelectric element comprising at least two layers of piezoelectric material that have different piezoelectric characteristics; and

applying an activation light to the piezoelectric element to change the state of the optical switch,

said applying an activation light comprising applying two light signals, which are out of phase with each other, to the piezoelectric element and then removing one of the light signals, leaving the remaining light signal as the activation light.

5. The method of claim 1 wherein the optical switch further comprises a conductive layer adjacent to the piezoelectric element that enhances said electrical field.

6. The method of claim 1 wherein two layers of the piezoelectric element have different crystal orientations.

7. An optical switch comprising:

a signal channel configured to guide a signal light; and

a piezoelectric element adjacent to the signal channel, the piezoelectric element comprising at least two layers of piezoelectric material that have different piezoelectric characteristics;

wherein passage of the signal light through the signal channel is controlled by the application of an activation light to the piezoelectric element,

said piezoelectric element being activated by an electrical field of said activation light, without said activation light impinging on said piezoelectric element.

8. The optical switch of claim 7 wherein two layers of the piezoelectric element have different crystal orientations.

9. The optical switch of claim 7 wherein two layers of the piezoelectric element have perpendicular crystal orientations.

10. The optical switch of claim 7 further comprising a conductive layer adjacent to the piezoelectric element, wherein the conductive layer enhances said electrical field.

11. The optical switch of claim 10 wherein the conductive layer is adhered to a surface of the piezoelectric element.

12. The optical switch of claim 10 wherein the conductive layer is adhered between two layers of the piezoelectric element.

13. The optical switch of claim 7 wherein said application of the activation light to the piezoelectric element causes the shape of the piezoelectric element to change such that the signal light is not able to pass through the signal channel.

14. The optical switch of claim 7 wherein the signal channel comprises a chamber that is filled with a compressible material.

15. The optical switch of claim 14 wherein the piezoelectric element forms a portion of the chamber.

16. A method for operating an optical switch, the method comprising:

applying a signal light to a signal channel, the signal channel being adjacent to a piezoelectric element that has at least two layers of piezoelectric material that have different piezoelectric characteristics; and

applying an activation light to the piezoelectric element to change the shape of the piezoelectric element such that the signal light is prevented from passing through the signal channel,

said piezoelectric element being activated by an electrical field of said activation light, without said activation light impinging on said piezoelectric element.

17. The method of claim 16 wherein the optical switch further comprises a conductive layer adjacent to the piezoelectric element that enhances said electrical field.

18. An optical switch comprising:

a signal channel configured to guide a signal light;

a piezoelectric element adjacent to the signal channel, the piezoelectric element comprising at least two different layers that have different piezoelectric characteristics; and

means for applying an activation light to the piezoelectric element to change the shape of the piezoelectric element such that the signal light is prevented from passing through the signal channel,

said piezoelectric element being activated by an electrical field of said activation light, without said activation light impinging on said piezoelectric element.

19. The optical switch of claim 18 wherein two layers of the piezoelectric element have different crystal orientations.

20. The optical switch of claim 18 further comprising means for coupling the signal light and the activation light into the signal channel.

21. The optical switch of claim 18 wherein the means for applying an activation light comprises an activation light source.

22. The optical switch of claim 18 further comprising a conductive layer adjacent to the piezoelectric element, wherein the conductive layer enhances said electrical field.

23. The optical switch of claim 22 wherein the conductive layer is adhered to a major surface of the piezoelectric element.