Wireless non-radiative energy transfer
The electromagnetic energy transfer device includes a first resonator structure receiving energy from an external power supply. The first resonator structure has a first Q-factor. A second resonator structure is positioned distal from the first resonator structure, and supplies useful working power to an external load. The second resonator structure has a second Q-factor. The distance between the two resonators can be larger than the characteristic size of each resonator. Non-radiative energy transfer between the first resonator structure and the second resonator structure is mediated through coupling of their resonant-field evanescent tails.
1. A method of transferring electromagnetic energy comprising:
providing a first electromagnetic resonator structure receiving energy from an external power supply, said first resonator structure having a first mode with a resonant frequency ω 1 , an intrinsic loss rate Γ 1 , and a first Q-factor Q 1 =ω 1 /(2Γ 1 ),
providing a second electromagnetic resonator structure being positioned distal from said first resonator structure and not electrically wired to the first resonator structure, said second resonator structure having a second mode with a resonant frequency ω 2 , an intrinsic loss rate Γ 2 , and a second Q-factor Q 2 =ω 2 /(2Γ 2 ),
transferring electromagnetic energy from said first resonator structure to said second resonator structure over a distance D that is smaller than each of the resonant wavelengths λ 1 and λ 2 corresponding to the resonant frequencies ω 1 and ω 2 , respectively,
wherein the electromagnetic resonator structures are designed to have Q 1 >100 and Q 2 >100.
2. The method of claim 1 , wherein the two said frequencies ω 1 and ω 2 are close to within the narrower of Γ 1 , and Γ 2 .
3. The method of claim 1 , wherein Q 1 >200, and Q 2 >200.
4. The method of claim 1 , wherein Q 1 >500, and Q 2 >500.
5. The method of claim 1 , wherein Q 1 >1000, and Q 2 >1000.
6. An electromagnetic energy transfer system comprising:
a first electromagnetic resonator structure receiving energy from an external power supply, said first resonator structure having a first mode with a resonant frequency ω 1 , an intrinsic loss rate Γ 1 , and a first Q-factor Q 1 ω 1 /(2Γ 1 ), and
a second electromagnetic resonator structure being positioned distal from said first resonator structure and not electrically wired to the first resonator structure, said second resonator structure having a second mode having a resonant frequency ω 2 , said second resonator structure having a second mode with a resonant frequency ω 2 , an intrinsic loss rate Γ 2 , and a second Q-factor Q 2 =ω 2 /(2Γ 2 ),
wherein said first resonator transfers electromagnetic energy to said second resonator over a distance D that is smaller than each of the resonant wavelengths λ 1 and λ 2 corresponding to the resonant frequencies w 1 and ω 2 , respectively,
wherein the electromagnetic resonator structures are designed to have Q 1 >100 and Q 2 >100.
7. The energy transfer system of claim 6 , wherein Q 1 >200, and Q 2 >200.
8. The energy transfer system of claim 6 , wherein said first resonator structure comprises a dielectric sphere having a radius defining a characteristic size L 1 for the first resonator structure.
9. The energy transfer system of claim 6 , wherein said first resonator structure comprises a metallic sphere having a radius defining a characteristic size L 1 for the first resonator structure.
10. The energy transfer system of claim 6 , and wherein said first resonator structure comprises a metallodielectric sphere having a radius defining a characteristic size L 1 for the first resonator structure.
11. The energy transfer system of claim 6 , wherein said first resonator structure comprises a plasmonic sphere having a radius defining a characteristic size L 1 for the first resonator structure.
12. The energy transfer system of claim 6 , wherein said first resonator structure comprises a polaritonic sphere having a radius defining a characteristic size L 1 for the first resonator structure.
13. The energy transfer device of claim 6 , and said first resonator structure comprises a capacitively-loaded conducting-wire loop, where the radius of the loop defines a characteristic size L 1 for the first resonator structure.
14. The energy transfer system of claim 6 , and said second resonator structure comprises a dielectric sphere, having a radius defining a characteristic size L 2 for the second resonator structure.
15. The energy transfer system of claim 6 , and said second resonator structure comprises a metallic sphere, having a radius defining a characteristic size L 2 for the second resonator structure.
16. The energy transfer system of claim 6 , and said second resonator structure comprises a metallodielectric sphere, having a radius defining a characteristic size L 2 for the second resonator structure.
17. The energy transfer system of claim 6 , and said second resonator structure comprises a plasmonic sphere, having a radius defining a characteristic size L 2 for the second resonator structure.
18. The energy transfer system of claim 6 , and said second resonator structure comprises a polaritonic sphere, having a radius defining a characteristic size L 2 for the second resonator structure.
19. The energy transfer device of claim 6 , and said second resonator structure comprises a capacitively-loaded conducting-wire loop, where the radius of the loop defines a characteristic size L 2 for the second resonator structure.
20. The method of claim 1 , wherein the rate of energy transfer from said first resonator structure to said second resonator structure is denoted by κ, and wherein the resonator structures are designed to have Q 1 and Q 2 satisfy κ/√{square root over (Γ 1 Γ 2 )}>0.2.
21. The method of claim 20 , wherein κ/sqrt(Γ 1 *Γ 2 )>0.5.
22. The method of claim 21 , wherein the second resonator structure has a characteristic size L 2 and D/L 2 >1.
23. The method of claim 22 , wherein D/L 2 >3.
24. The method of claim 23 wherein D/L 2 >5.
25. The method of claim 20 , wherein κ/sqrt(Γ 1 *Γ 2 )>1.
26. The method of claim 25 , wherein the second resonator structure has a characteristic size L 2 and D/L 2 >1.
27. The method of claim 26 , wherein D/L 2 >3.
28. The method of claim 27 wherein D/L 2 >5.
29. The method of claim 20 , wherein κ/sqrt(Γ 1 *Γ 2 )>5.
30. The method of claim 29 , wherein the second resonator structure has a characteristic size L 2 and D/L 2 >1.
31. The method of claim 30 , wherein D/L 2 >3.
32. The method of claim 31 wherein D/L 2 >5.
33. The method of claim 3 , wherein the rate of energy transfer from said first resonator structure to said second resonator structure is denoted by κ, and wherein the resonator structures are designed to have Q 1 and Q 2 satisfy κ/sqrt(Γ 1 *Γ 2 )>0.5.
34. The method of claim 33 , wherein the second resonator structure has a characteristic size L 2 and D/L 2 >1.
35. The method of claim 34 , wherein D/L 2 >3.
36. The method of claim 35 , wherein D/L 2 >5.
37. The method of claim 3 , wherein the rate of energy transfer from said first resonator structure to said second resonator structure is denoted by κ, and wherein the resonator structures are designed to have Q 1 and Q 2 satisfy κ/sqrt(Γ 1 *Γ 2 )>1.
38. The method of claim 37 , wherein the second resonator structure has a characteristic size L 2 and D/L 2 >1.
39. The method of claim 38 , wherein D/L 2 >3.
40. The method of claim 39 , wherein D/L 2 >5.
41. The system of claim 6 , wherein the rate of energy transfer from said first resonator structure to said second resonator structure is denoted by κ, and wherein the resonator structures are designed to have Q 1 and Q 2 satisfy κ/sqrt(Γ1*Γ2)>0.2.
42. The system of claim 41 , wherein the second resonator structure has a characteristic size L 2 and D/L 2 >1.
43. The system of claim 42 , wherein D/L 2 >3.
44. The system of claim 43 , wherein D/L 2 >5.
45. The system of claim 6 , wherein the rate of energy transfer from said first resonator structure to said second resonator structure is denoted by κ, and wherein the resonator structures are designed to have Q 1 and Q 2 satisfy κ/sqrt(Γ 1 *Γ 2 )>0.5.
46. The system of claim 45 , wherein the second resonator structure has a characteristic size L 2 and D/L 2 >1.
47. The system of claim 46 , wherein D/L 2 >3.
48. The system of claim 47 , wherein D/L 2 >5.
49. The system of claim 6 , wherein the rate of energy transfer from said first resonator structure to said second resonator structure is denoted by κ, and wherein the resonator structures are designed to have Q 1 and Q 2 satisfy κ/sqrt(Γ 1 *Γ 2 )>1.
50. The system of claim 49 , wherein the second resonator structure has a characteristic size L 2 and D/L 2 >1.
51. The system of claim 50 , wherein D/L 2 >3.
52. The system of claim 51 , wherein, D/L 2 >5.
53. The system of claim 7 , wherein the rate of energy transfer from said first resonator structure to said second resonator structure is denoted by κ, and wherein the resonator structures are designed to have Q 1 and Q 2 satisfy κ/sqrt(Γ1*Γ2)>0.2.
54. The system of claim 53 , wherein the second resonator structure has a characteristic size L 2 and D/L 2 >1.
55. The system of claim 54 , wherein D/L 2 >3.
56. The system of claim 55 , wherein D/L 2 >5.
57. The system of claim 6 , wherein Q 1 >500, and Q 2 >500.
58. The method of claim 1 , wherein the first and second resonator structures are movable relative to one another.
59. The system of claim 6 , wherein the first and second resonator structures are movable relative to one another.
60. The system of claim 6 , wherein the two said frequencies ω 1 and ω 2 are close to within the narrower of the two resonance widths Γ 1 , and Γ 2 .
61. The method of claim 1 , wherein D>1 cm.
62. The method of claim 1 , wherein D>30 cm.
63. The method of claim 1 , wherein D>1 m.
64. The system of claim 6 , wherein D>1 cm.
65. The system of claim 6 , wherein D>30 cm.
66. The system of claim 6 , wherein D>1 m.
67. The method of claim 1 , wherein the first resonator structure has a characteristic size L 1 and the second resonator structure has a characteristic size L 2 , and D/L 1 >1 and D/L 2 >1.
68. The system of claim 6 , wherein the first resonator structure has a characteristic size L 1 and the second resonator structure has a characteristic size L 2 , and D/L 1 >1 and D/L 2 >1.
69. The method of claim 1 , further comprising applying a feedback mechanism to at least one of the resonator structures to correct for detuning of its resonant frequency.
70. The system of claim 6 , further comprising a feedback mechanism coupled to at least one of the resonator structures to correct for detuning of its resonant frequency.