Nonlinear optical whispering gallery mode resonators

• US 6,943,934 B1
• Filed: 05/28/2003
• Issued: 09/13/2005
• Est. Priority Date: 05/28/2002
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Matsko, Andrey B., Ilchenko, Vladimir, Savchenkov, Anatoliy, Maleki, Lutfollah
• Primary Examiner(s): Lee, John D.
• Application Number:
  US10/447,673
• Time in Patent Office: 839 Days
• Field of Search: 359326-332, 385/15, 385/24, 385/27, 385/28, 385/39, 385/50
• US Class Current: 359/326
• CPC Class Codes: G02B 6/29335 Evanescent coupling to a resonator cavity, i.e. between a waveguide mode and a resonant mode of the cavity wavelength selective means based on resonator cavity coupled non-evanescently G02B6/29356, G02B6/29358
• CPC Class Codes: G02B 6/29341 Loop resonators operating in a whispering gallery mode evanescently coupled to a light guide, e.g. sphere or disk or cylinder evanescent coupling for sensing fluorescence G01N21/648

Abstract

Whispering gallery mode (WGM) optical resonators comprising nonlinear optical materials, where the nonlinear optical material of a WGM resonator includes a plurality of sectors within the optical resonator and nonlinear coefficients of two adjacent sectors are oppositely poled.

Claims

1. A device, comprising an optical resonator including a nonlinear optical material to support whispering gallery modes, and an optical coupler to couple light into or out of said optical resonator, wherein said nonlinear optical material includes a plurality of sectors within said optical resonator and nonlinear coefficients of two adjacent sectors are oppositely poled.

2. The device as in claim 1, wherein said resonator is a sphere.

3. The device as in claim 1, wherein said optical resonator has a non-spherical shape.

4. The device as in claim 1, wherein said optical resonator has a disk shape.

5. The device as in claim 1, wherein said optical resonator has a ring shape.

6. The device as in claim 1, wherein said sectors are symmetrically arranged with respect to a center of said optical-resonator.

7. The device as in claim 1, wherein said sectors are parallel stripes across said optical resonator.

8. The device as in claim 1, wherein said nonlinear optical material is LiNbO₃.

9. The device as in claim 1, wherein said nonlinear optical material exhibit a second-order nonlinear optical effect.

10. A device, comprising an optical resonator comprising a nonlinear optical material to support whispering gallery modes, wherein said nonlinear optical material comprises a plurality of sectors within said optical resonator and nonlinear coefficients of two adjacent sectors are oppositely poled, wherein said optical resonator includes a portion of a sphere.

11. A device, comprising an optical resonator which comprises a nonlinear optical material to support whispering gallery modes, wherein said nonlinear optical material comprises a plurality of sectors within said optical resonator and nonlinear coefficients of two adjacent sectors are oppositely poled, wherein said optical resonator has a spheroidal shape.

12. A method, comprising:

providing an optical resonator having a nonlinear optical material to support whispering gallery modes, wherein the nonlinear optical material includes a plurality of sectors across the optical resonator and nonlinear coefficients of two adjacent sectors are oppositely poled; and

coupling an optical beam at a first wavelength into the optical resonator to convert light at the first wavelength into light at a second, different wavelength.

13. The method as in claim 12, wherein the conversion of light includes a second harmonic generation process, where the second wavelength is one half of the first wavelength.

14. The method as in claim 12, wherein the conversion of light includes a parametric oscillation process, the method further comprising coupling another optical beam at a third wavelength into the optical resonator.

15. The method as in claim 12, wherein the sectors are symmetrically arranged with respect to a center of the optical resonator.

16. The method as in claim 12, wherein the sectors are parallel stripes across the optical resonator.

17. The method as in claim 12, wherein the nonlinear optical material exhibits an electro-optical effect, and the method further comprising applying a modulation electric signal to the optical resonator to control the refractive index to modulate the light at the second wavelength.

18. A device, comprising an optical resonator configured to support whispering gallery modes and including a nonlinear optical material exhibiting a second-order nonlinear effect, wherein said nonlinear optical material includes a plurality of sectors within said optical resonator and said sectors are in a quasi phase matching configuration for said second-order nonlinear effect for light coupled in said optical resonator.

19. The device as in claim 18, wherein said optical resonator includes at least a portion of a sphere.

20. The device as in claim 18, wherein said optical resonator has a non-spherical shape.

21. The device as in claim 20, wherein said optical resonator has a spheroidal shape.

22. The device as in claim 18, wherein said sectors are symmetrically arranged with respect to a center of said optical resonator.

23. The device as in claim 18, wherein said sectors are parallel stripes across said optical resonator.

24. The device as in claim 23, wherein said sectors have different widths.

25. The device as in claim 18, wherein said nonlinear optical material exhibits an electro-optical effect, and said device further comprising an electrode to apply an electrical signal to modulate light that is involved in said second-order nonlinear effect.