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论文类型：期刊论文

发表刊物：Phys. Rev. B

所属单位：DTU Fotonik, Department of Photonics Engineering, Ørsteds Plads, Building 345v, DK-2800 Kongens Lyng

刊物所在地：美国

学科门类：工学

项目来源：自然科学基金

文献类型：J

卷号：81

期号：12

页面范围：125431

关键字：无

DOI码：10.1103/PhysRevB.81.125431

发表时间：2010-03-15

摘要：We develop a self-consistent finite-element method to quantitatively study spontaneous emission from emitters in nanoscale proximity of plasmonic waveguides. In the model, it is assumed that only one guided mode is dominatingly excited by the quantum emitter, while the cross section of the plasmonic waveguide can be arbitrary. The fraction of the energy coupled to the plasmonic mode can be calculated exactly, which can be used to determine the efficiency with which single optical plasmons are generated. We apply our numerical method to calculate the coupling of a quantum emitter to a cylindrical metallic nanowire and a square metallic waveguide, and compare the cylindrical metallic nanowire with previous work that employs quasistatic approximation. For the cylindrical metallic nanowire we observe good agreement with the quasistatic approximation for radii below 10 nm, but for increasing radius the spontaneous emission β factor and the plasmonic decay rate deviate substantially, by factors of up to 5–10 for a radius of ∼100 nm, from the values obtained in the quasistatic approximation. We also show that the quasistatic approximation is typically valid when the radius is less than the skin depth of the metals at optical frequencies. For the square metallic waveguide we estimate an optimized value for the spontaneous emission β factor up to 80%.

备注：无

发布期刊链接：https://doi.org/10.1103/PhysRevB.81.125431