A Frequency-Dependent LOD-FDTD Method and Its Application to the Analyses of Plasmonic Waveguide Devices

作者：Shibayama Jun^*; Nomura Akifumi; Ando Ryoji; Yamauchi Junji; Nakano Hisamatsu

来源：IEEE Journal of Quantum Electronics, 2010, 46(1): 40-49.

DOI：10.1109/JQE.2009.2024328

• Alternating-direction implicit finite-difference time-domain method (ADI-FDTD)
• auxiliary differential equation (ADE)
• dispersive media
• surface plasmon polariton (SPP)

Detailed frequency-dependent formulations are presented for several efficient locally one-dimensional finite-difference time-domain methods (LOD-FDTDs) based on the recursive convolution (RC), piecewise linear RC (PLRC), trapezoidal RC (TRC), auxiliary differential equation, and transform techniques. The performance of each technique is investigated through the analyses of surface plasmon waveguides, the dispersions of which are expressed by the Drude and Drude-Lorentz models. The simple TRC technique requiring a single convolution integral is found to offer the comparable accuracy to the PLRC technique with two convolution integrals. As an application, a plasmonic grating filter is studied using the TRC-LOD-FDTD. The use of an apodized and a chirped grating is found quite effective in reducing sidelobes in the transmission spectrum, maintaining a large bandgap. Furthermore, a plasmonic microcavity is analyzed, in which a defect section is introduced into a grating filter. Varying the air core width is shown to exhibit tunable properties of the resonance wavelength.

• 出版日期2010-1