Light activated optical switch that includes a piezoelectric element and a conductive layer
A light activated optical switch includes at least one conductive layer located adjacent to a piezoelectric element to enhance the electrical field that is applied to the piezoelectric element in response to an activation light. The conductive layer has free electrons or electron holes that collect on a surface adjacent to the piezoelectric element when the activation light is applied to the piezoelectric element. The collection of free electrons near the piezoelectric element enhances the electrical field that is applied to the piezoelectric element in response to the activation light. The enhanced electrical field is used to enhance the performance of the piezoelectric clement and ultimately to enhance the performance of the optical switch.
1 . A method for operating an optical switch, the method comprising:
applying a signal light to an optical switch that comprises a piezoelectric element and at least one conductive layer adjacent to the piezoelectric element; and
applying an activation light to the piezoelectric element to change the state of the optical switch;
wherein the conductive layer enhances an electrical field applied to the piezoelectric clement in response to the applied activation light.
2 . The method of claim 1 wherein the conductive layer is adhered to a surface of the piezoelectric element.
3 . The method of claim 2 wherein 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.
4 . The method of claim 1 wherein applying the activation light comprises 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 piezoelectric element comprises at least two layers that have different piezoelectric characteristics.
6 . The method of claim 5 wherein two layers of the conductive element have different crystal orientations.
7 . The method of claim 5 wherein the conductive layer is adhered between two layers of the piezoelectric element.
8 . An optical switch comprising:
a signal channel configured to guide a signal light;
a piezoelectric element adjacent to the signal channel; and
a conductive layer adjacent to the piezoelectric element;
wherein passage of the signal light through the signal channel is controlled by the application of an activation light to the piezoelectric element and wherein the conductive layer enhances an electrical field applied to the piezoelectric element in response to the activation light.
9 . The optical switch of claim 8 wherein the conductive layer is adhered to a surface of the piezoelectric element.
10 . The optical switch of claim 8 wherein 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.
11 . The optical switch of claim 8 wherein the signal channel comprises a chamber that is filled with a compressible material.
12 . The optical switch of claim 8 wherein the piezoelectric element forms a portion of the chamber.
13 . The optical switch of claim 8 wherein the piezoelectric element comprises at least two layers that have different piezoelectric characteristics.
14 . The optical switch of claim 13 wherein two layers of the conductive element have different crystal orientations.
15 . The optical switch of claim 13 wherein the conductive layer is adhered between two layers of the piezoelectric element.
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 is adjacent to at least one conductive layer; 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,
wherein the conductive layer enhances an electrical field applied to the piezoelectric element in response to the applied activation light.
17 . The method of claim 16 wherein the piezoelectric element comprises at least two layers that have different piezoelectric characteristics.
18 . The method of claim 17 wherein the conductive layer is adhered between two layers of the piezoelectric element.
19 . An optical switch comprising:
a signal channel configured to guide a signal light;
a piezoelectric element adjacent to the signal channel;
a conductive layer adjacent to the piezoelectric element; 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;
wherein the conductive layer enhances an electrical field applied to the piezoelectric element in response to the applied activation light.
20 . The optical switch of claim 19 further comprising means for coupling the signal light and the activation light into the signal channel.
21 . The optical switch of claim 19 wherein the means for applying an activation light comprises an activation light source.
22 . The optical switch of claim 19 wherein the piezoelectric element comprises at least two layers that have different piezoelectric characteristics.
23 . The optical switch of claim 22 wherein the conductive layer is adhered between two layers of the piezoelectric element.