Kim Jinhyung, Song Jung-Hwan, Jeong Kwang-Yong, Ee Ho-Seok, Seo Min-Kyo
Opt Express. 2015 May 4;23(9):11080-91. doi: 10.1364/OE.23.011080.
We present a full three-dimensional (3D) power flow analysis of an emitter-nanoantenna system. A conventional analysis, based on the total Poynting vector, calculates only the coupling strength in terms of the Purcell enhancement. For a better understanding of the emitter-nanoantenna system, not only the Purcell enhancement but also complete information on the energy transfer channels is necessary. The separation of the pure scattering and emitter output Poynting vectors enables the quantification of the individual energy transfer channels. Employing the finite-difference time-domain method (FDTD), we examine a nanodisk antenna that supports the bright dipole and dark quadrupole resonance modes for which the power flow characteristics are completely distinct, and we analyze the power flow enhancements to the energy transfer channels with respect to the wavelength, polarization, and position of the emitter coupled to the antenna. The 3D power flow analysis reveals how the constructive or destructive interference between the emitter and the antenna resonance mode affects the power flow enhancements and the far-field radiation pattern. Our proposed power flow analysis should play a critical role in characterizing the emitter-antenna system and customizing its energy transfer properties for desired applications.
我们展示了一种发射器 - 纳米天线系统的完整三维（3D）功率流分析。基于总坡印廷矢量的传统分析仅根据珀塞尔增强来计算耦合强度。为了更好地理解发射器 - 纳米天线系统，不仅需要珀塞尔增强，还需要有关能量转移通道的完整信息。纯散射坡印廷矢量和发射器输出坡印廷矢量的分离能够对各个能量转移通道进行量化。采用时域有限差分法（FDTD），我们研究了一种支持亮偶极子和暗四极子共振模式的纳米盘天线，其功率流特性完全不同，并且我们分析了相对于与天线耦合的发射器的波长、极化和位置，能量转移通道的功率流增强情况。三维功率流分析揭示了发射器与天线共振模式之间的相长或相消干涉如何影响功率流增强和远场辐射方向图。我们提出的功率流分析在表征发射器 - 天线系统以及为所需应用定制其能量转移特性方面应发挥关键作用。
