Pseudospectral Modeling of Nano-Optics in Ag Sphere Arrays

We report a Legendre pseudospectral modeling of silver sphere arrays illuminated by light waves. A special feature of the present computation is that the dispersive nature of silver is described by a Drude-Lorentz model with model parameters obtained by fitting the frequency-domain complex-valued dielectric constants measured experimentally. Numerical validations are conducted based on solving both the near and far fields of the Mie scattering problem, and we observe good convergence on the numerical fields. The far-field patterns of the Ag sphere arrays are simulated. The results are compared to those obtained by the A paper in memory of Prof. David Gottlieb. This work is supported by National Science Council of Taiwan, grant No. NSC 96-2120-M-001-002. B.-Y. Lin · H.-C. Chang Graduate Institute of Communication Engineering, National Taiwan University, Taipei 10617, Taiwan C.-H. Teng ( ) Department of Applied Mathematics, National Chiao Tung University, Hsinchu 30010, Taiwan e-mail: [email protected] C.-H. Teng Center of Mathematical Modeling and Scientific Computing, National Chiao Tung University, Hsinchu 30010, Taiwan H.-C. Chang Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan H.-C. Chang · H.-H. Hsiao Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan J.-K. Wang · Y.-L. Wang Institute of Atomic and Molecular Science, Academia Sinica, Taipei 10617, Taiwan J.-K. Wang Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan Y.-L. Wang Department of Physics, National Taiwan University, Taipei 10617, Taiwan 430 J Sci Comput (2010) 45: 429–446 dipole-coupling-model method, and we observe very good agreement between these results. The near-field patterns are also computed, and localized enhanced electric fields in the interparticle gap regions due to plasmonic coupling between Ag particles are visualized. As the gap between Ag particles is reduced the strength of the localized enhanced electric field is increased.