Mechanically tunable optical devices such as interferometers

• US 6,970,619 B2
• Filed: 03/31/2003
• Issued: 11/29/2005
• Est. Priority Date: 05/21/2001
• Status: Expired due to Term

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Walker, James A., Stuart, Howard R., Dinu, Mihaela, Baumann, Frieder H.
• Primary Examiner(s): KIANNI, KAVEH C
• Application Number:
  US10/403,872
• Publication Number:
  US 20050074209A1
• Time in Patent Office: 974 Days
• Field of Search: 385/25, 385/16, 385/15, 385/14, 385/9, 385/8, 385/13, 385/2, 385/3, 385/4, 385/100, 372/92, 372/43
• US Class Current: 385/25
• CPC Class Codes: G02B 6/12007 forming wavelength selective elements, e.g. multiplexer, demultiplexer
• 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 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/3596 With planar waveguide arrangement, i.e. in a substrate, regardless if actuating mechanism is outside the substrate

Abstract

An optical device has at least one waveguide with at least one adjacent resonator, where the distance between the resonator and the waveguide can be controllably adjusted to change the optical coupling between the resonator and the waveguide. When implemented as part of an interferometer, the ability to adjust the waveguide/resonator distance—and thereby the optical coupling between them—provides a mechanically tunable interferometer.

Claims

1. An optical device having one or more waveguides, the optical device comprising:

a first waveguide; and

a first resonator positioned adjacent to the first waveguide, wherein the distance between the first resonator and the first waveguide is adapted to be controllably adjusted to change the optical coupling between the first waveguide and the first resonator, wherein;

the first waveguide is movable and the first resonator is stationary; and

the first waveguide is adapted to move relative to the first resonator when an electrostatic potential difference is applied between the first waveguide and one or more stationary electrodes rigidly connected to the first resonator.

2. The optical device of claim 1, wherein the optical device is an interferometer comprising two or more waveguides including the first waveguide, wherein the distance between the first resonator and the first waveguide is adapted to be controllably adjusted to enable mechanical tuning of the optical performance of the interferometer.

3. The optical device of claim 2, wherein:

the interferometer is a Mach-Zehnder interferometer having two waveguides; and

the resonator is a ring or disk resonator.

4. The optical device of claim 2, wherein the interferometer is part of an all-optical switch.

5. The optical device of claim 4, wherein the all-optical switch comprises a plurality of the interferometers.

6. The optical device of claim 1, wherein the optical device is an all-optical switch.

7. The optical device of claim 1, wherein the optical device is part of an all-optical switch and the all-optical switch comprises a plurality of the optical devices.

8. The optical device of claim 1, wherein:

the optical device is implemented on a substrate having the one or more stationary electrodes; and

the first waveguide comprises a mechanically active region that is adapted to move relative to the substrate when the electrostatic potential difference is applied between the first waveguide and the one or more electrodes, wherein the motion of the first waveguide changes the distance between the first waveguide and the resonator.

9. The optical device of claim 8, wherein the substrate has first and second sets of one or more stationary electrodes disposed on the substrate such that:

when an electrostatic potential difference is applied between the first waveguide and the first set of one or more electrodes, the distance between the first waveguide and the resonator tends to decrease; and

when an electrostatic potential difference is applied between the first waveguide and the second set of one or more electrodes, the distance between the first waveguide and the resonator tends to increase.

10. The optical device of claim 1, wherein the optical device is fabricated using one or more materials having an intrinsic figure of merit T greater than one.

11. The optical device of claim 10, wherein the optical device has an effective figure of merit FOM_eff greater than one.

12. The optical device of claim 1, wherein:

the optical device is an interferometer comprising two or more waveguides including the first waveguide, wherein the distance between the first resonator and the first waveguide is adapted to be controllably adjusted to enable mechanical tuning of the optical performance of the interferometer;

the interferometer is a Mach-Zehnder interferometer having two waveguides;

the resonator is a ring or disk resonator;

the interferometer is part of an all-optical switch comprising a plurality of the interferometers;

the optical device is implemented on a substrate having the one or more stationary electrodes;

the first waveguide comprises a mechanically active region that is adapted to move relative to the substrate when the electrostatic potential difference is applied between the first waveguide and the one or more electrodes, wherein the motion of the first waveguide changes the distance between the first waveguide and the resonator;

the substrate has first and second sets of one or more stationary electrodes disposed on the substrate such that;

when an electrostatic potential difference is applied between the first waveguide and the first set of one or more electrodes, the distance between the first waveguide and the resonator tends to decrease; and

when an electrostatic potential difference is applied between the first waveguide and the second set of one or more electrodes, the distance between the first waveguide and the resonator tends to increase;

the optical device is fabricated using one or more materials having an intrinsic figure of merit T greater than one; and

the optical device has an effective figure of merit FOM_eff greater than one.

13. The optical device of claim 1, further comprising a second waveguide, wherein:

the first resonator is positioned between the first and second waveguides;

at a first selected distance between the first resonator and the first waveguide, light entering the first waveguide is substantially coupled from the first waveguide into the first resonator and then from the first resonator into the second waveguide; and

at a second selected distance between the first resonator and the first waveguide, light entering the first waveguide is not substantially coupled from the first waveguide into the first resonator.

14. The optical device of claim 13, wherein the optical device is an add-drop filter.

15. The optical device of claim 13, further comprising one or more additional resonators positioned between the first and second waveguides, wherein the first and one or more additional resonators are adapted to resonate at different light frequencies.

16. The optical device of claim 1, further comprising a second waveguide, wherein:

the first resonator and the first and second waveguides form an interferometer;

at a first selected distance between the first resonator and the first waveguide, light entering the first waveguide substantially exists at a first output port of the interferometer; and

at a second selected distance between the first resonator and the first waveguide, light entering the first waveguide substantially exists at a second output port of the interferometer.

17. An optical device having one or more waveguides, the optical device comprising:

a first waveguide; and

a first resonator positioned adjacent to the first waveguide, wherein;

the distance between the first resonator and the first waveguide is adapted to be controllably adjusted to change the optical coupling between the first waveguide and the first resonator;

the optical device is an interferometer comprising two or more waveguides including the first waveguide;

the distance between the first resonator and the first waveguide is adapted to be controllably adjusted to enable mechanical tuning of the optical performance of the interferometer;

the interferometer is part of an all-optical switch; and

the all-optical switch comprises a plurality of the interferometers.

18. An optical device having one or more waveguides, the optical device comprising:

a first waveguide; and

a first resonator positioned adjacent to the first waveguide, wherein;

the distance between the first resonator and the first waveguide is adapted to be controllably adjusted to change the optical coupling between the first waveguide and the first resonator;

the optical device is implemented on a substrate having one or more stationary electrodes;

the first waveguide comprises a mechanically active region that is adapted to move relative to the substrate when an electrostatic potential difference is applied between the first waveguide and the one or more electrodes; and

the motion of the first waveguide changes the distance between the first waveguide and the resonator.

19. The optical device of claim 18, wherein the substrate has first and second sets of one or more stationary electrodes disposed on the substrate such that:

when an electrostatic potential difference is applied between the first waveguide and the first set of one or more electrodes, the distance between the first waveguide and the resonator tends to decrease; and

when an electrostatic potential difference is applied between the first waveguide and the second set of one or more electrodes, the distance between the first waveguide and the resonator tends to increase.

20. An optical device having one or more waveguides, the optical device comprising:

a first waveguide; and

a first resonator positioned adjacent to the first waveguide, wherein;

the distance between the first resonator and the first waveguide is adapted to be controllably adjusted to change the optical coupling between the first waveguide and the first resonator; and

the optical device is fabricated using one or more materials having an intrinsic figure of merit T greater than one.

21. The optical device of claim 20, wherein the optical device has an effective figure of merit FOM_eff greater than one.