Patent ID: 7825543

Claim:
An apparatus for use in wireless energy transfer, the apparatus comprising: a first resonator structure configured for energy transfer with a second resonator structure, over a distance D larger than a characteristic size L 1 of said first resonator structure or larger than a characteristic size L 2 of said second resonator structure, wherein the energy transfer has a rate κ and is mediated by evanescent-tail coupling of a resonant field of the first resonator structure and a resonant field of the second resonator structure, wherein said resonant field of the first resonator structure has a resonance angular frequency ω 1 , a resonance frequency-width Γ 1 , and a resonance quality factor Q 1 =ω 1 /2Γ 1 at least larger than 100, and said resonant field of the second resonator structure has a resonance angular frequency ω 2 , a resonance frequency-width Γ 2 , and a resonance quality factor Q 2 =ω 2 /2Γ 2 at least larger than 100, wherein the absolute value of the difference of said angular frequencies ω 1 and ω 2 is smaller than the broader of said resonant widths Γ 1 , and Γ 2 .