Development of the Finite-Difference Time-Domain Method for Photonics Problems of Different Material Characteristics
Date Issued
2007
Date
2007
Author(s)
Chang, Han-chih
DOI
en-US
Abstract
With the uniaxial perfectly matched layer employed in the model, we develop a full-vectorial finite-difference time-domain (FDTD) method for numerical model of various photonics structures of different materials, including anisotropic, nonlinear, and metallic materials, simultaneously in one single computational domain. Detailed modeling issues of various materials are explicitly elaborated in order to extend the full power of the FDTD algorithm. The junction loss for a two-dimensional (2D) photonic crystal waveguide made of traditional dielectric materials is investigated and explained. We also study the photonic quasicrystals fabricated from multiple exposure techniques. The transmission properties of the 2D photonic quasicrystal slabs are calculated and compared with those of the 2D photonic crystal slabs. Also explored are anisotropic materials, focused on the transmission properties of a 2D air-hole anisotropic photonic crystal slab and a 2D liquid-crystal-hole dielectric photonic crystal slab, which combine the concepts of photonic crystals and anisotropic materials. Important modeling techniques about noble materials in the visible spectral range are discussed to include the absorption band at lower wavelengths (which is missing from the widely used Drude model), and a more realistic model, featuring the combinations of the Drude model and the multiple-pole Lorentz model, is demonstrated. We further apply this more realistic model to investigate the actual absorption effect for the transmission property of 2D metallic nanostrip arrays, with the material ranging from gold, silver, copper, and the perfect conductor. A 3D FDTD simulation is performed on a 3D metallic nanorod array, and the possibility and limitation of this structure as a new tool for subwavelength optical imaging are discussed. Finally the instantaneous third-order nonlinear materials are addressed. Comparisons are made between our nonlinear FDTD simulation and the analytical prediction under the slowly-varying envelope approximation, for the parametric four-wave mixing process.
Subjects
有限差分時域法
光子晶體
光子準晶體
非線性材料
FDTD
finite-difference time-domain method
photonic crystal
photonic quasicrystal
metallic material
the Drude model
the Lorentz model
subwavelength optical imaging
instantaneous third-order nonlinearity
kerr medium
FWM
parametric four-wave mixing process
Type
thesis
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