Optically transparent electrically conductive charge sheet poling electrodes to maximize performance of electro-optic devices

• US 6,782,166 B1
• Filed: 07/01/2002
• Issued: 08/24/2004
• Est. Priority Date: 12/21/2001
• Status: Expired due to Fees

• Current Assignee: Air Force Government of The United States of America As Represented By The Secretary
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Grote, James G., Nelson, Robert L.
• Primary Examiner(s): Palmer, Phan T. H.
• Application Number:
  US10/185,844
• Time in Patent Office: 785 Days
• Field of Search: 385/2, 385/3, 385/8, 385/37, 385/40, 385/122, 385/129-132
• US Class Current: 385/40
• CPC Class Codes: G02F 1/065 in an optical waveguide structure
• CPC Class Codes: G02F 2201/12 electrode
• CPC Class Codes: G02F 2202/20 LiNbO3, LiTaO3

Abstract

A non-liner electron-optic polymer based, integrated optic, electron-optic device utilizing a non-liner electron-optic polymer for the optical wave guide core layer sandwich between two very thin optically transparent electrically conductive charge sheet poling electrode layers which are, in turn, sandwiched between two electrically passive polymer optical wave guide cladding layers.

Claims

1. A minimal propagation loss, electro-optic coefficient maximizing electrically controlled polymer-based optical signal modulation and switching device requiring minimal operating voltage comprising:

a first electrically grounded metal layer overlaying a substrate layer and functioning as an electrical ground electrode;

a first electrically passive polymer cladding layer overlaying said first metal layer and including therein an aperture communicating with said grounded metal layer;

a first optically transparent electrically conductive charge sheet layer overlaying said first electrically passive polymer cladding layer, said first optically transparent electrically conductive charge sheet layer including an integral portion extending through said aperture of said first electrically passive polymer cladding layer and making electrical contact with said first electrically grounded metal layer;

an optical signal transmitting non-linear electro-optic polymer core layer having electrically alterable molecular structure and optical refraction properties;

a second optically transparent electrically conductive charge sheet layer overlaying said optical signal transmitting non-linear electro-optic polymer core layer, said first and second optically transparent electrically conductive charge sheet layers being capable of establishing an electric field region encompassing said optical signal transmitting non-linear electro-optic polymer core layer in said modulation or switching device;

a second electrically passive polymer cladding layer overlaying said second optically transparent electrical conductive charge sheet layer; and

a second metal layer overlaying said second electrically passive polymer cladding layer and interfacing a switch controlling electrical signal voltage source with said second optically transparent electrically conductive charge sheet layer through said second electrically passive polymer cladding layer;

said non-linear electro-optic polymer core layer transmitting an optical signal in a predictably altered path therein upon application of electric field-sustaining voltage between said first and second optically transparent electrically conductive charge sheet layers.

2. The minimal propagation loss, electro-optic coefficient maximizing electrically controlled polymer-based optical signal modulation and switching device requiring minimal operating voltage of claim 1, wherein said first and second optically transparent electrically conductive charge sheet poling electrode layers are comprised of a metal from the group consisting of gold and silver, and a ferroelectric compound from the group consisting of lithium niobate and barium titanate, and a conductive polymer from the group consisting of poly(ethylene dioxythiophene) and hydrochloric acid doped poly(anilene).

3. The minimal propagation loss, electro-optic coefficient maximizing electrically controlled polymer-based optical signal modulation and switching device requiring minimal operating voltage of claim 2, wherein a thickness dimension of each of said first and second optically transparent electrically conductive charge sheet poling electrode layers is less than 100 nanometers.

4. The minimal propagation loss, electro-optic coefficient maximizing electrically controlled polymer-based optical signal modulation and switching device requiring minimal operating voltage of claim 2, wherein said optical signal transmitting polymer core layer has a thickness of one to three microns.

5. The minimal propagation loss, electro-optic coefficient maximizing electrically controlled polymer-based optical signal modulation and switching device requiring minimal operating voltage of claim 2, wherein said optical signal propagation loss is less than 1 decibel per centimeter of device length.

6. The minimal propagation loss, electro-optic coefficient maximizing electrically controlled polymer-based optical signal modulation and switching device requiring minimal operating voltage of claim 2, wherein total poling voltage is between 100 and 450 volts and between 100 and 150 volts per micron across the non-linear electro-optic polymer core layer.

7. The minimal propagation loss, electro-optic coefficient maximizing electrically controlled polymer-based optical signal modulation and switching device requiring minimal operating voltage of claim 2, wherein said modulation and switching device has a length of less than 3 centimeters.

8. The minimal propagation loss, electro-optic coefficient maximizing electrically controlled polymer-based optical signal modulation and switching device requiring minimal operating voltage of claim 1, wherein said first and second optically transparent electrically conductive charge sheet poling electrode layers comprise first and second electrically passive polymer layers that confine the optical signal within the non-linear electro-optic polymer core layer for minimum optical propagation loss.

9. The minimal propagation loss, electro-optic coefficient maximizing electrically controlled polymer-based optical signal modulation and switching device requiring minimal operating voltage of claim 1, wherein said first and second electrically passive polymer layers that confine the optical signal within the non-linear electro-optic polymer core layer for minimum optical propagation loss comprise electrodes for said modulation and switching device operation.

10. A method for fabricating a non-linear electro-optic polymer based optical signal modulation and switching device comprising the steps of:

depositing a first metal layer onto a substrate;

forming a first electrically passive polymer cladding layer onto said metal layer;

forming a first optically transparent electrically conductive charge sheet poling electrode layer onto said electrically passive polymer cladding layer;

forming a non-linear electro-optic polymer core layer onto said first electrically passive polymer cladding layer;

forming a second optically transparent electrically conductive charge sheet poling electrode layer onto said non-linear electro-optic polymer core layer, forming a second electrically passive polymer cladding layer onto said second optically transparent electrically conductive charge sheet poling electrode layer; and

depositing a second metal layer onto said second electrically passive polymer cladding layer.

11. The method for fabricating a non-linear electro-optic polymer based optical signal modulation and switching device of claim 10, including the step of providing non-linear properties in said non-linear electro-optic polymer core layer by applying heat and DC voltage thereto.

12. The method for fabricating a non-linear electro-optic polymer based optical signal modulation and switching device of claim 11, wherein said forming steps include the step of spin coating.

13. The method for fabricating a non-line electro-optic polymer based optical signal modulation and switching device of claim 12, wherein said steps for fabricating said first and second optically transparent electrically conductive charge sheet poling electrode layers include plasma deposition and spin coating of metal, ferroelectric, semiconductor and conductive polymer material.

14. The method for fabricating a non-line electro-optic polymer based optical signal modulation and switching device of claim 12, wherein said step of spin coating a non-linear electro-optic polymer core layer achieves a 1 to 3 micron polymer core layer.

15. The method for fabricating a non-linear electro-optic polymer based optical signal modulation and switching device of claim 11, wherein said total DC poling voltage is 100 to 450 volts or 100 to 150 volts per micron across the non-linear electro-optic polymer core layer.

16. The method for fabricating a non-linear electro-optic polymer based optical signal modulation and switching device of claim 10, wherein said first and second optically transparent electrically conductive charge sheet poling electrode layers each achieve an optically transparent electrically conductive charge sheet poling electrode layer of less than 100 nanometer thickness.

17. A The method for fabricating a non-linear electro-optic polymer based optical signal modulation and switching device of claim 10, including the step of etching wave guides in the desired shape of said modulation or switching device using photolithography.

18. An electrically controlled, non-linear electro-optic polymer material-based method for modulation and switching an optical signal comprising the steps of:

transmitting an optical signal through a plurality of wave-guides integral with a polymer core layer; and

applying an electric poling field to said non-linear electro-optic polymer core layer, said electric field commencing at a first metal electrode layer adjacent to a first electrically passive polymer cladding layer adjacent through a first electrically conductive via to a first optically transparent electrically conductive charge sheet polymer electrode layer adjacent to the first lateral surface of said non-linear electro-optic polymer core layer adjacent to a second optically transparent electrically conductive charge sheet polymer electrode layer adjacent to the second electrically passive polymer cladding layer and terminating to a second metal electrode layer through a second electrically conductive via, said electric poling field predictably poling the non-linear electro-optic polymer core to its maximum non-linearity.

19. The electrically controlled, non-linear electro-optic polymer based method for modulation or switching an optical signal of claim 18, wherein said step of applying an electric poling field to said non-linear electro-optic polymer core layer comprises supplying a first electrical potential to a first metallic layer communicating with said first electrically passive polymer cladding layer and first optically transparent electrically conductive charge sheet poling electrode layer through a first electrically conductive via and a non-linear electro-optic polymer core layer and a second optically transparent electrically conductive charge sheet poling electrode layer and a second electrically passive polymer cladding layer to a second metallic layer through a second electrically conductive via.