Time-domain Modeling of Light Matter Interactions in Active Plasmonic Metamaterials
Metamaterials are artificially engineered to obtain unprecedented electromagnetic control leading to new and exciting applications. In order to further the understanding of fundamental optical phenomena and explore the effects of dynamically changing media on light propagation, numerous modeling methods have been developed. Among them, due to the nature of transient, nonlinear, and impulsive behavior, the time domain modeling approach is viewed as the most viable method. In this work, we develop a time-domain model (method of finite-difference time-domain (FDTD)) of light matter interactions in active plasmonic metamaterials. In order to model the dispersion of plasmonic nanostructure in the time-domain, we introduce a generalized dispersive material model built on Padé approximants. The developed 3D FDTD solver is then applied to study several plasmonic nanostructures and metamaterials, such as metal-dielectric composite films, random nano-nets for transparent conducting electrodes, and a graphene photodetector enhanced by a fractal plasmonic metasurface. In addition to this we also developed a multi-physics time-domain model to investigate the properties of a silver nanohole array coated with Rhodamine-101 dye. With accurate modeling of the retrieved kinetic parameters, the simulated emission intensity shows clear lasing, which is in good agreement with our experimental measurements. By tracing the population inversion and polarization dynamics, the amplification and lasing regimes inside the nanohole cavity can be clearly distinguished. With the help of our systematic approach, we further the understanding of time-resolved physics in active plasmonic nanostructures with gain.
Shalaev, Purdue University.
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