Negatively-refractive focusing and sensing apparatus, methods, and systems

• US 9,019,632 B2
• Filed: 07/25/2008
• Issued: 04/28/2015
• Est. Priority Date: 05/30/2008
• Status: Active Grant

• Current Assignee: The Invention Science Fund I, L.L.C. (Intellectual Ventures LLC)
• Original Assignee: The Invention Science Fund I, L.L.C. (Intellectual Ventures LLC)
• Inventors: Bowers, Jeffrey A., Hyde, Roderick A., Jung, Edward K. Y., Pendry, John Brian, Schurig, David, Smith, David R., Tegreene, Clarence T., Weaver, Thomas A., Whitmer, Charles, Wood, Lowell L. Jr.
• Primary Examiner(s): Sugarman, Scott J
• Application Number:
  US12/220,705
• Publication Number:
  US 20090296225A1
• Time in Patent Office: 2,468 Days
• Field of Search: 359/724, 359/721, 359/672, 359/676, 343/700.R
• US Class Current: 359/721
• CPC Class Codes: G02B 27/40 Optical focusing aids

Abstract

Apparatus, methods, and systems provide negatively-refractive focusing and sensing of electromagnetic energy. In some approaches the negatively-refractive focusing includes providing an interior focusing region with an axial magnification substantially greater than one. In some approaches the negatively-refractive focusing includes negatively-refractive focusing with a transformation medium, where the transformation medium may include an artificially-structured material such as a metamaterial.

Claims

1. An electromagnetic apparatus, comprising:

a negatively-refractive focusing structure disposed to receive electromagnetic energy in an interior focusing region with an axial magnification greater than one; and

at least one electromagnetic sensor positioned within the interior focusing region;

wherein the negatively-refractive focusing structure is characterized by electromagnetic parameters that define a negative index of refraction within at least a portion of the interior focusing region and the electromagnetic parameters include;

axial electromagnetic parameters; and

transverse electromagnetic parameters that inversely correspond to the axial electromagnetic parameters.

2. The electromagnetic apparatus of claim 1, wherein the negative index of refraction is less than zero and greater than minus one within at least a portion of the interior focusing region.

3. The electromagnetic apparatus of claim 1, wherein the negatively-refractive focusing structure defines an axial direction, and the axial electromagnetic parameters correspond to the axial direction.

4. The electromagnetic apparatus of claim 3, wherein the transverse electromagnetic parameters correspond to a transverse direction, the transverse direction being substantially perpendicular to the axial direction.

5. The electromagnetic apparatus of claim 1, wherein the axial electromagnetic parameters include an axial permittivity.

6. The electromagnetic apparatus of claim 5, wherein the transverse electromagnetic parameters include a transverse permittivity that is substantially a multiplicative inverse of the axial permittivity.

7. The electromagnetic apparatus of claim 6, wherein the axial permittivity is less than minus one.

8. The electromagnetic apparatus of claim 5, wherein the axial electromagnetic parameters include an axial permeability.

9. The electromagnetic apparatus of claim 8, wherein the transverse electromagnetic parameters include a transverse permeability that is substantially a multiplicative inverse of the axial permeability.

10. The electromagnetic apparatus of claim 9, wherein the axial permeability is less than minus one.

11. The electromagnetic apparatus of claim 8, wherein the axial permittivity is substantially equal to the axial permeability.

12. The electromagnetic apparatus of claim 11, wherein the transverse electromagnetic parameters include a transverse permeability that is substantially a multiplicative inverse of the axial permeability.

13. The electromagnetic apparatus of claim 12, wherein the axial permeability is less than minus one.

14. The electromagnetic apparatus of claim 1,

wherein the negatively-refractive focusing structure includes an input surface region that is substantially nonreflective of electromagnetic energy incident upon the input surface region.

15. The electromagnetic apparatus of claim 14, wherein the input surface region is substantially nonreflective of electromagnetic energy incident upon the input surface region from an adjacent region, the adjacent region being exterior to the negatively-refractive focusing structure.

16. The electromagnetic apparatus of claim 15, wherein a wave impedance of the adjacent region is substantially equal to a wave impedance of the input surface region.

17. The electromagnetic apparatus of claim 16, wherein the adjacent region defines a first permittivity and a first permeability, the input surface region defines a second permittivity and a second permeability, and a ratio of the second permittivity to the first permittivity is substantially equal to a ratio of the second permeability to the first permeability.

18. The electromagnetic apparatus of claim 17, wherein the second permittivity is less than zero.

19. The electromagnetic apparatus of claim 17, wherein the second permeability is less than zero.

20. The electromagnetic apparatus of claim 19, wherein the second permittivity is less than zero.

21. The electromagnetic apparatus of claim 17, wherein the input surface region defines a surface normal direction and a surface parallel direction, the second permittivity includes a surface normal permittivity corresponding to the surface normal direction and a surface parallel permittivity corresponding to the surface parallel direction, and a ratio of the surface normal permittivity to the first permittivity is substantially a multiplicative inverse of a ratio of the surface parallel permittivity to the first permittivity.

22. The electromagnetic apparatus of claim 21, wherein the ratio of the surface normal permittivity to the first permittivity is less than minus one.

23. The electromagnetic apparatus of claim 21, wherein the second permeability includes a surface normal permeability corresponding to the surface normal direction and a surface parallel permeability corresponding to the surface parallel direction, and a ratio of the surface normal permeability to the first permeability is substantially a multiplicative inverse of a ratio of the surface parallel permeability to the first permeability.

24. The electromagnetic apparatus of claim 23, wherein the ratio of the surface normal permittivity to the first permittivity is less than minus one.

25. An electromagnetic apparatus, comprising:

a negatively-refractive focusing structure disposed to receive electromagnetic energy in an interior focusing region with an axial magnification greater than one; and

at least one electromagnetic sensor positioned within the interior focusing region;

wherein the negatively-refractive focusing structure is characterized by electromagnetic parameters that define a negative index of refraction within at least a portion of the interior focusing region and the electromagnetic parameters include;

axial electromagnetic parameters; and

transverse electromagnetic parameters that inversely correspond to the axial electromagnetic parameters;

wherein the negatively-refractive focusing structure includes an artificially-structured material having an effective electromagnetic response that corresponds to the electromagnetic parameters; and

wherein the artificially-structured material includes a photonic crystal.

26. An electromagnetic apparatus, comprising:

a negatively-refractive focusing structure disposed to receive electromagnetic energy in an interior focusing region with an axial magnification greater than one; and

at least one electromagnetic sensor positioned within the interior focusing region;

wherein the negatively-refractive focusing structure is characterized by electromagnetic parameters that define a negative index of refraction within at least a portion of the interior focusing region and the electromagnetic parameters include;

axial electromagnetic parameters; and

transverse electromagnetic parameters that inversely correspond to the axial electromagnetic parameters;

wherein the negatively-refractive focusing structure includes an artificially-structured material having an effective electromagnetic response that corresponds to the electromagnetic parameters; and

wherein the artificially-structured material includes a metamaterial.

27. The electromagnetic apparatus of claim 26, wherein the interior focusing region is at least partially inside the artificially-structured material.

28. The electromagnetic apparatus of claim 27, wherein the interior focusing region is completely inside the artificially-structured material.

29. The electromagnetic apparatus of claim 26, wherein the metamaterial includes at least one electromagnetically-responsive structure having a plurality of distributed electromagnetic responses, the plurality of distributed electromagnetic responses composing the effective electromagnetic response.

30. The electromagnetic apparatus of claim 29, wherein the distributed electromagnetic responses include distributed inductive responses.

31. The electromagnetic apparatus of claim 29, wherein the distributed electromagnetic responses include distributed capacitive responses.

32. The electromagnetic apparatus of claim 29, wherein the distributed electromagnetic responses include distributed inductive-capacitive responses.

33. The electromagnetic apparatus of claim 29, wherein the at least one electromagnetically-responsive structure includes transmission lines.

34. The electromagnetic apparatus of claim 26, wherein the metamaterial includes a plurality of electromagnetically responsive elements disposed at a plurality of spatial locations and having a plurality of individual responses, the plurality of individual responses composing the effective electromagnetic response.

35. The electromagnetic apparatus of claim 34, wherein the electromagnetically responsive elements include discrete circuit elements.

36. The electromagnetic apparatus of claim 35, wherein the discrete circuit elements include inductors.

37. The electromagnetic apparatus of claim 35, wherein the discrete circuit elements include capacitors.

38. The electromagnetic apparatus of claim 35, wherein the discrete circuit elements include semiconductor devices.

39. The electromagnetic apparatus of claim 38, wherein the semiconductor devices include diodes.

40. The electromagnetic apparatus of claim 38, wherein the semiconductor devices include transistors.

41. The electromagnetic apparatus of claim 34, wherein the electromagnetically responsive elements include integrated circuit elements.

42. The electromagnetic apparatus of claim 34, wherein the electromagnetically responsive elements include printed circuit elements.

43. The electromagnetic apparatus of claim 34, wherein the electromagnetically responsive elements include metallic structures.

44. The electromagnetic apparatus of claim 34, wherein the electromagnetically responsive elements include LC resonators.

45. The electromagnetic apparatus of claim 34, wherein the electromagnetically responsive elements include plasmonic resonators.

46. The electromagnetic apparatus of claim 34, wherein the electromagnetically responsive elements include nanostructures.

47. The electromagnetic apparatus of claim 46, wherein the nanostructures include nanorods.

48. The electromagnetic apparatus of claim 47, wherein the nanorods are paired nanorods.

49. The electromagnetic apparatus of claim 47, wherein the nanorods are interconnected to compose a fishnet structure.

50. The electromagnetic apparatus of claim 34, wherein the electromagnetically responsive elements include split-ring resonators.

51. The electromagnetic apparatus of claim 34, wherein the electromagnetically responsive elements include subwavelength elements having spatial extents substantially less than a free space wavelength corresponding to a frequency of the electromagnetic energy.

52. The electromagnetic apparatus of claim 26, wherein the at least one electromagnetic sensor includes at least one antenna.

53. The electromagnetic apparatus of claim 26, wherein the at least one electromagnetic sensor includes at least one photodetector.

54. The electromagnetic apparatus of claim 26, further comprising:

a plurality of electromagnetic sensors positioned within the interior focusing region.

55. The electromagnetic apparatus of claim 54, wherein the plurality of electromagnetic sensors is an axially distributed plurality of electromagnetic sensors.

56. The electromagnetic apparatus of claim 54, wherein the plurality of electromagnetic sensors includes a plurality of antennas.

57. The electromagnetic apparatus of claim 56, wherein the plurality of antennas composes an antenna phased array.