Cost-effective Finite Difference Time Domain Simulations on Extreme Subwavelength Metallic Slot Antennas

초록

Metallic slot antennas operating at millimeter wavelengths can incorporate a giant electric field enhancement, potentially useful in various light–matter interactions. However, the giant mismatch between the operating wavelength and the feature size can result in an enormous computational cost for electromagnetic simulations, thus hindering the theoretical prediction of the optical properties of the nano-slots. Therefore, by treating the metallic layer as a single-cell-thick effective medium in finite difference time domain (FDTD) simulations, in this study, we aim to correctly predict the optical properties of metallic slot antennas while substantially reducing the computational cost. First, the metallic film is modeled as a single-mesh-thick medium and the effective conductivity of the metal is found to determine the correct values for a direct transmission through the film. Then, transmissions through the slot antennas are calculated and compared to the known results obtained from coupled mode methods. Finally, coupled slot antenna structures are calculated and their applicability is discussed. © 2022 The Korean Physical Society. All rights reserved.

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