Extraordinary optical properties of structured metals
Date : November 7, 2007 16:00 ~
Speaker : Francisco J. García-Vidal(Universidad Autónoma de Madrid)
Professor :
Location : 56동106호
Extraordinary optical properties of structured metals
Francisco J. García-Vidal
Departamento de Física Teórica de la Materia Condensada,
Universidad Autónoma de Madrid, E-28049 Madrid, Spain
In this talk we address from a theoretical point of view two physical phenomena that are related to the excitation of surface electromagnetic (EM) resonances (surface plasmons) at structured metal surfaces: i) extraordinary optical transmission through single and periodically structured subwavelength apertures and ii) beaming of light through single apertures surrounded by periodic corrugations.
First we analyze the pioneering experiment of Ebbesen et al. on 2D hole arrays in the optical regime by presenting a fully three-dimensional numerical treatment of the structure. Moreover, we will show how subwavelength holes (2D arrays or 1D linear chains) in a perfect conductor also gives rise to similar extraordinary transmission even though the free surface of an unperforated perfect conductor has no surface modes. We will see that there are not two separate mechanisms: the holes will spoof surface plasmons which play the same resonant role as the real ones on silver or gold in the optical regime.
Then, we will discuss the enhanced optical transmission phenomenon and beaming effects both observed in single subwavelength apertures (holes or slits) flanked by periodic corrugations. We will present the theoretical foundation for these phenomena and discuss the various dependences of the transmission and emission profiles on the geometrical parameters defining the system, providing guidelines for the optimisation of these profiles for different possible applications, like lensing.
Finally, we will explore how these results found for metal surfaces can be exported to dielectric photonic crystals (PCs), to sonic waves or even to matter waves.
Francisco J. García-Vidal
Departamento de Física Teórica de la Materia Condensada,
Universidad Autónoma de Madrid, E-28049 Madrid, Spain
In this talk we address from a theoretical point of view two physical phenomena that are related to the excitation of surface electromagnetic (EM) resonances (surface plasmons) at structured metal surfaces: i) extraordinary optical transmission through single and periodically structured subwavelength apertures and ii) beaming of light through single apertures surrounded by periodic corrugations.
First we analyze the pioneering experiment of Ebbesen et al. on 2D hole arrays in the optical regime by presenting a fully three-dimensional numerical treatment of the structure. Moreover, we will show how subwavelength holes (2D arrays or 1D linear chains) in a perfect conductor also gives rise to similar extraordinary transmission even though the free surface of an unperforated perfect conductor has no surface modes. We will see that there are not two separate mechanisms: the holes will spoof surface plasmons which play the same resonant role as the real ones on silver or gold in the optical regime.
Then, we will discuss the enhanced optical transmission phenomenon and beaming effects both observed in single subwavelength apertures (holes or slits) flanked by periodic corrugations. We will present the theoretical foundation for these phenomena and discuss the various dependences of the transmission and emission profiles on the geometrical parameters defining the system, providing guidelines for the optimisation of these profiles for different possible applications, like lensing.
Finally, we will explore how these results found for metal surfaces can be exported to dielectric photonic crystals (PCs), to sonic waves or even to matter waves.