Transverse-longitudinal integrated resonator

• US 6,532,326 B1
• Filed: 09/21/2000
• Issued: 03/11/2003
• Est. Priority Date: 09/21/2000
• Status: Expired due to Fees

• Current Assignee: UT-Battelle LLC
• Original Assignee: UT-Battelle LLC
• Inventors: Simpson, John T., Simpson, Marcus L., Hutchinson, Donald P.
• Primary Examiner(s): Ullah, Akm E.
• Assistant Examiner(s): CONNELLY, MICHELLE R
• Application Number:
  US09/667,178
• Time in Patent Office: 901 Days
• Field of Search: 385/12, 385/47, 385/48, 385/129-132
• US Class Current: 385/37
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 2006/12145 Switch
• CPC Class Codes: G02B 6/12007 forming wavelength selective elements, e.g. multiplexer, demultiplexer
• CPC Class Codes: G02B 6/1225 comprising photonic band-gap structures or photonic lattices
• CPC Class Codes: G02B 6/124 Geodesic lenses or integrated gratings

Abstract

A transverse-longitudinal integrated optical resonator (TLIR) is disclosed which includes a waveguide, a first and a second subwavelength resonant grating in the waveguide, and at least one photonic band gap resonant structure (PBG) in the waveguide. The PBG is positioned between the first and second subwavelength resonant gratings. An electro-optic waveguide material may be used to permit tuning the TLIR and to permit the TLIR to perform signal modulation and switching. The TLIR may be positioned on a bulk substrate die with one or more electronic and optical devices and may be communicably connected to the same. A method for fabricating a TLIR including fabricating a broadband reflective grating is disclosed. A method for tuning the TLIR'"'"'s transmission resonance wavelength is also disclosed.

Claims

1. A transverse-longitudinal integrated optical resonator (TLIR), comprising:

a waveguide;

a first and a second subwavelength resonant grating in said waveguide, and

a photonic band gap resonant structure (PBG) having a plurality of features in said waveguide, said PBG positioned between said first and second subwavelength resonant gratings.

2. The TLIR of claim 1, wherein said first and second subwavelength resonant gratings and said PBG features are embedded in said waveguide.

3. The TLIR of claim 1, wherein said waveguide is at least one selected from the group consisting of Si, Ge, ZnSe, BaF₂, CdTe, LiNbO₃ and SBN.

4. The TLIR of claim 1, wherein said waveguide is formed from at least one electro-optic material.

5. The TLIR of claim 4, wherein said electro-optic waveguide material is at least one selected from the group consisting of CdTe, LiNbO₃ and SBN.

6. The TLIR of claim 1, wherein said waveguide is a substantially planar waveguide, and further comprising at least one cladding layer positioned adjacent to said substantially planar waveguide.

7. The TLIR of claim 6, wherein said waveguide is formed from an electro-optic material and said at least one cladding layer comprises at least one lower buffer layer positioned under said waveguide and at least one upper buffer layer positioned over said waveguide.

8. The TLIR of claim 7, further comprising a pair of electrically conductive discharge electrodes, wherein said waveguide is positioned between said electrically conductive discharge electrodes, said electrically conductive discharge electrodes being separated from said waveguide by said buffer layers.

9. The TLIR of claim 8, further comprising a bulk substrate material and a RF oscillator, wherein said RF oscillator is formed on said bulk substrate material and is electrically connected to said electrically conductive discharge electrodes.

10. A method for transforming an electromagnetic signal which comprises utilizing the apparatus of claim 9, wherein utilizing includes optical computing.

11. A method for transforming an electromagnetic signal which comprises utilizing the apparatus of claim 9, wherein utilizing includes optical signal modulation.

12. The TLIR of claim 6, wherein said at least one cladding layer has a lower index of refraction than said waveguide.

13. The TLIR of claim 12, wherein said cladding layer is at least one selected from the group consisting of glasses and BaF₂.

14. The TLIR of claim 1, wherein said plurality of PBG features comprise at least one row of PBG features having at least one defect therein.

15. The TLIR of claim 14, wherein said defect is at least one selected from the group consisting of a spacing defect, a size defect and a refractive index defect.

16. The TLIR of claim 15, wherein said PBG features are holes.

17. The TLIR of claim 16, wherein said holes are filled with at least one gas.

18. The TLIR of claim 17, wherein said gas is air.

19. The TLIR of claim 14, wherein said PBG features are arranged in linear arrays.

20. The TLIR of claim 14, wherein a resonator formed by said first and second resonant gratings have a first transmission resonance and said PBG has a second transmission resonance, wherein said transmission resonances are substantially equal.

21. The TLIR of claim 20, wherein said resonator sustains substantially only one propagating mode.

22. The TLIR of claim 20, wherein said resonator sustains more than one propagating mode.

23. The TLIR of claim 1, wherein each said subwavelength resonant grating structure comprises a substantially periodic array of SWS features.

24. The TLIR of claim 23, wherein said SWS features from said first and second resonant grating are arranged in substantially linear arrays.

25. The TLIR of claim 24, wherein said SWS features from said first and second resonant grating are arranged along arcs having a radius of curvature.

26. The TLIR of claim 24, wherein said SWS features are formed from a material having a refractive index higher than that of a material comprising said waveguide.

27. The TLIR of claim 26, wherein said SWS features are formed from at least one selected from the group consisting of Ge, BaF₂, LiNbO₃, SBN and Si.

28. The TLIR of claim 1, wherein said PBG features are arranged along arcs having a radius of curvature.

29. The TLIR of claim 1, further comprising a structure for cooling.

30. The TLIR of claim 1, further comprising a bulk substrate material having a plurality of die, each said die having at least one electronic device, wherein said TLIR is positioned on said die.

31. The TLIR of claim 30, wherein said TLIR is communicably connected to one or more of said electronic devices.

32. A method for transforming an electromagnetic signal which comprises utilizing the apparatus of claim 1, wherein utilizing includes wavelength division de-multiplexing.

33. A composite optical resonator, comprising at least two transverse-longitudinal integrated optical resonators (TLIR) connected in series, each TLIR comprising:

a waveguide;

a first and second subwavelength resonant grating structure in said waveguide, and

a photonic band gap resonant structure (PBG) having a plurality of features in said waveguide, wherein said PBG is positioned between said first and second subwavelength resonant grating structures.

34. A composite optical resonator, comprising at least two transverse-longitudinal integrated optical resonators (TLIR) connected in parallel, each TLIR comprising:

a waveguide;

a first and second subwavelength resonant grating structure in said waveguide, and

at least one photonic band gap resonant structure (PBG) having a plurality of features in said waveguide, wherein said PBG is positioned between said first and second subwavelength resonant grating structure.

35. A gas detector, comprising a plurality of transverse-longitudinal integrated optical resonators (TLIR) connected in parallel, comprising:

a waveguide;

a first and second subwavelength resonant grating structure in said waveguide, and

at least one photonic band gap resonant structure (PBG) having a plurality of features in said waveguide, said PBG positioned between said first and second subwavelength resonant grating structure, wherein said plurality of TLIRs exhibit transmission resonances centered at more than one wavelength.

36. The gas detector of claim 35, further comprising a bulk substrate material having a plurality of die, each said die having at least one electronic device, wherein said gas detector is positioned on said die.

37. A method for tuning a transmission resonance of a transverse-longitudinal integrated optical resonator (TLIR) comprising the steps of:

providing a first and second subwavelength resonant grating structure in a waveguide, said first and second subwavelength resonant grating structure having a first resonant transmission wavelength;

providing a photonic band gap resonant structure (PBG) in said waveguide, said PBG positioned between said first and second subwavelength resonant grating structures, said PBG having a second resonant transmission wavelength, and

tuning at least one of said transmission resonances to result in said transmission resonance wavelengths being substantially equal.

38. The method for tuning the TLIR of claim 37, wherein following said tuning, a nominal transmission resonance wavelength (λ

) divided by a difference between said PBG transmission resonance wavelength and said transmission resonance wavelength of said first and second subwavelength resonant gratings is less than a square root of the product of a Q of said PBG Q and a Q of said first and second subwavelength resonant gratings.

39. The method for tuning the TLIR of claim 38, wherein following said tuning, a nominal transmission resonance wavelength (λ

) divided by a difference between said PBG transmission resonance wavelength and said transmission resonance wavelength of said first and second subwavelength resonant gratings is less than one half a square root of the product of a Q of said PBG Q and a Q of said first and second subwavelength resonant gratings.

40. The method for tuning the TLIR of claim 37, wherein said tuning is at least one selected from the group of electo-optic, photo-refractive, thermal, magneto-optic and tilting.

41. A method of forming a transverse-longitudinal integrated optical resonator (TLIR) in a waveguide, comprising the steps of:

providing a first and second subwavelength resonant grating structure in said waveguide, and

providing a photonic band gap resonant structure (PBG) having a plurality of features in said waveguide, wherein said PBG is positioned between said first and second subwavelength resonant grating structure.

42. A method of forming a transverse-longitudinal integrated optical resonator (TLIR) in a waveguide positioned on a bulk substrate material, said bulk substrate material having a plurality of die, comprising the steps of:

selecting said die;

providing a first and second subwavelength resonant grating structure in said waveguide, and

providing a photonic band gap resonant structure (PBG) having a plurality of features in said waveguide, wherein said PBG is positioned between said first and second subwavelength resonant grating structure.

43. The method of forming a TLIR of claim 42, further comprising a step of planarizing said waveguide.

44. The method of forming a TLIR of claim 43, further comprising the step of providing at least one cladding layer, said at least one cladding layer formed over said bulk substrate material.

45. The method of forming a TLIR of claim 44, wherein said at least one cladding layer comprises at least one lower buffer layer under said waveguide and at least one upper buffer layer over said waveguide.

46. The method of forming a TLIR of claim 45, further comprising the steps of forming a first electrically conductive film over said at least one lower buffer layer and forming a second electrically conductive film over said at least one upper buffer layer, said electrically conductive films each forming electrically conductive discharge electrodes, wherein said waveguide is positioned between said electrically conductive discharge electrodes, said electrically conductive discharge electrodes being separated from said waveguide by said buffer layers.

47. The method of forming a TLIR of claim 46, further comprising the step of forming an RF oscillator on said bulk substrate material, said RF oscillator being electrically connected to said electrically conductive films.