2009/09/26 by Yuntian Chen, Yahong Chen, Torben Roland Nielsen +4 · 139 citations
Engineering · Physics and Astronomy · #Atomic physics #Common emitter #Condensed matter physics #Excited state #Laser #Nanowire #Optics #Optoelectronics #Photonic Crystals and Applications #Photonic and Optical Devices #Physics #Plasmon #Plasmonic and Surface Plasmon Research #Quantum #Quantum mechanics #Quantum wire #Quasistatic approximation #Quasistatic process #RADIUS #Spontaneous emission #Waveguide #physics.optics
paper · pdf · doi:10.1103/physrevb.81.125431
published in Physical Review B 81(12) (American Physical Society) · 12 pages, 8 figures
arxiv created 2009/09/26 · openalex publication_date 2010/03/25 · arxiv updated 2012/08/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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 \ensuremathβ factor and the plasmonic decay rate deviate substantially, by factors of up to 5--10 for a radius of \ensuremath∼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 \ensuremathβ factor up to 80%.