Integrated microelectromechanical polymeric photonic switch

• US 5,367,585 A
• Filed: 10/27/1993
• Issued: 11/22/1994
• Est. Priority Date: 10/27/1993
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Polla, Dennis L., Saia, Richard J., Yakymyshyn, Christopher P., Ghezzo, Mario
• Primary Examiner(s): Lee, John D.
• Assistant Examiner(s): Heartney, Phan Thi
• Application Number:
  US08/144,165
• Time in Patent Office: 391 Days
• Field of Search: 385/23, 385/129, 385/130, 385/131, 385/132, 385/40, 385/16.2, 385/17, 385/18
• US Class Current: 385/23
• CPC Class Codes: G02B 27/56 Optics using evanescent waves, i.e. inhomogeneous waves
• CPC Class Codes: G02B 6/3502 involving direct waveguide displacement, e.g. cantilever type waveguide displacement involving waveguide bending, or displacing an interposed waveguide between stationary waveguides
• CPC Class Codes: G02B 6/3536 involving evanescent coupling variation, e.g. by a moving element such as a membrane which changes the effective refractive index mode converters G02B6/14; adjustable lateral coupling between waveguides G02B6/283; electro- optical refractive index variations G02F1/0118
• CPC Class Codes: G02B 6/3546 NxM switch, i.e. a regular array of switches elements of matrix type constellation
• 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

Abstract

A microelectromechanical photonic switch includes first and second waveguides. Insulative cladding containing a gap and having a lower refractive index than the refractive indices of the first and second waveguides is situated between the first and second waveguides. One electrode comprising an at least partially transparent material is situated on the same side of the gap as the second waveguide. An additional electrode is provided either on the same side of the gap as the first waveguide or over a piezoelectric strip above a cladding layer on the second waveguide. At least one of the electrodes is capable of being advanced towards the other of the electrodes so as to cause one of the first and second waveguides to advance towards the other of the first and second waveguides.

Claims

1. A microelectromechanical photonic switch, comprising:

a first optical waveguide having a first refractive index;

a second optical waveguide having a second refractive index;

insulative cladding between said first and second waveguides, said insulative cladding having a gap therein and having a lower refractive index than each of the first and second refractive indices, wherein said first waveguide is positioned with a predetermined first waveguide portion on one side of said gap and said second waveguide is positioned with a predetermined second waveguide portion substantially parallel to said predetermined first waveguide portion and situated on an opposing side of said gap;

a first cladding layer facing said first waveguide and said insulative cladding, said first cladding layer having a lower refractive index than said first refractive index;

a second cladding layer facing said second waveguide and said insulative cladding, said second cladding layer having a lower refractive index than said second refractive index; and

means for moving at least one of said predetermined first and second waveguide portions closer to the other of said predetermined first and second waveguide portions in response to an actuation force, said moving means comprising

a first electrode situated between a portion of said first cladding layer and said gap;

a second electrode situated between a portion of said second cladding layer and said gap; and

means for advancing at least one of said first and second electrodes towards the other of said first and second electrodes so as to advance one of said first and second waveguides towards the other of said first and second waveguides.

2. A microelectromechanical photonic switch, comprising;

a first optical waveguide having a first refractive index;

a second optical waveguide having a second refractive index;

insulative cladding between said first and second waveguides, said insulative cladding having a gap therein and having a lower refractive index than each of the first and second refractive indices, wherein said first waveguide is positioned with a predetermined first waveguide portion on one side of said gap and said second waveguide is positioned with a predetermined second waveguide portion substantially parallel to said predetermined first waveguide portion and situated on an opposing side of said gap; and

means for moving at least one of said predetermined first and second waveguide portions closer to the other of said predetermined first and second waveguide portions in response to an actuation force, said means for moving comprising

a first electrode;

a second electrode comprising an at least partially transparent material and situated between a portion of said second waveguide and a portion of said gap; and

means for advancing at least one of said first and second electrodes towards the other of said first and second electrodes so as to advance one of said first and second waveguides towards the other of said first and second waveguides.

3. The switch of claim 2, further comprising:

a first cladding layer facing said first waveguide and said insulative cladding, said first cladding layer having a lower refractive index than said first refractive index; and

a second cladding layer facing said second waveguide and said insulative cladding, said second cladding layer having a lower refractive index than said second refractive index.

4. The switch of claim 3, wherein said first electrode comprises an at least partially transparent material situated between a portion of said first waveguide and at least a portion of said gap, and further including an insulator layer situated between said first electrode and at least a portion of said gap.

5. The switch of claim 4, wherein said insulator layer comprises a layer selected from the group consisting of polymeric and silicon dioxide layers.

6. The switch of claim 5, wherein said first and second waveguides comprise a polyimide material and wherein said first and second electrodes comprise indium tin oxide.

7. The switch of claim 6, wherein said first and second cladding layers comprise a polyimide material and wherein said insulator layer comprises silicon dioxide.

8. The switch of claim 3, further comprising a substrate facing a surface of said first cladding layer, said surface of said first cladding layer facing away from said first waveguide and said insulative cladding.

9. The switch of claim 3, further including a piezoelectric strip line situated between said first electrode and said second cladding layer.

10. The switch of claim 9, wherein each of said first and second waveguides comprises a polyimide material, said second electrode comprises indium tin oxide, and said first electrode comprises a metal selected from the group consisting of chromium and platinum.

11. The switch of claim 10, wherein said first and second cladding layers comprise a polyimide material and wherein said piezoelectric strip line comprises lead zirconate titanate.

12. A method of fabricating a microelectro-mechanical photonic switch on a substrate, comprising the steps of:

applying a first cladding layer over said substrate;

applying a first waveguide over said first cladding layer;

applying a first electrode over said first cladding layer;

applying an insulative cladding over said first cladding layer, said insulative cladding having an opening extending through to at least a portion of said first waveguide;

applying a second electrode over a portion of said insulative cladding including a portion of said opening;

applying a second waveguide over said opening; and

applying a second cladding layer over said second waveguide.

13. The method of claim 12, further including the step of applying an insulator layer over said first electrode prior to applying said insulative cladding over said first cladding layer.

14. The method of claim 13, wherein a portion of said first waveguide is covered by said first electrode during the step of applying said first electrode over said first cladding layer.

15. The method of claim 12, further including the steps of:

applying a sacrificial layer in said opening prior to applying said second electrode; and

removing said sacrificial layer after applying said second electrode.

16. The method of claim 12, wherein the step of applying a first waveguide comprises applying a polymer material over said first cladding layer and exposing at least a selected portion of said polymer material to light to increase the index of refraction of said selected portion of the polymer and thereby form said first waveguide.

17. A method of fabricating a microelectro-mechanical photonic switch on a substrate, comprising the steps of:

applying a first cladding layer over said substrate;

applying a first waveguide over said first cladding layer;

applying an insulative cladding over said first cladding layer, said insulative cladding having an opening extending through to at least a portion of said first waveguide;

applying one electrode over a portion of said insulative cladding including at least a portion of said opening;

applying a second waveguide over said opening;

applying a second cladding layer over said second waveguide.

applying a piezoelectric strip line over said second cladding layer; and

applying an additional electrode over said piezoelectric strip line.

18. The method of claim 17, wherein a portion of said first waveguide is covered by said insulative cladding layer during the step of applying said insulative cladding over said first cladding layer.

19. The method of claim 17, further including the steps of:

applying a sacrificial layer in said opening prior to applying said one electrode; and

removing said sacrificial layer after applying said one electrode.