"How Light Emerges from an Illuminated Array of Subwavelength Apertures"

Abstract:  Surface plasmon polaritons are electromagnetic surface  waves that propagate at the interface between a metal and a  dielectric by the collective motion of electrons.  Unlike most guided modes, the electric fields associated with surface plasmon modes are evanescent and decay exponentially with distance from the interface.  When excited by an optical field in a metal film they can travel quite long distances along the metal's surfaces.  They also can turn back into a freely propagating optical radiation when they are scattered by periodic array of holes or grooves.  Recent works on extraordinary optical transmission and light beaming  in sub-wavelength periodically structured metal films suggest a direction for fabricating optical devices that operate below the diffraction limit and utilize the coherent fluctuations of surface plasmons.  Significant advances in this area may be possible if surface plasmons can be controllably converted to and from free-space photons, and if their surface propagation can be intentionally directed in two dimensions.  We demonstrate that surface plasmons can form coherent modes whose intensity and propagation direction can be manipulated by varying the wavelength, incidence angle, and polarization of the excitation light.  We also demonstrate the reverse conversion of surface plasmons back into light and observe directional beaming.  Plasmonic structures can be used to miniaturize and to integrate optical components into micro electronic devices: surface plasmon modes can propagate at near the speed of light supporting data transmission rates orders of magnitude faster than that of current electronic interconnects, or can be constricted to dimensions of a small fraction of the equivalent photon wavelength to concentrate electromagnetic fields used to control ultrafast electronics or for sensing and spectroscopy at nano-scales.

Girsh Blumberg received his Ph.D. in Physics and Mathematics from the Estonian Academy of Sciences in 1987.  Beginning in 1981, he was a Research/Senior Research Associate at the Institute of Chemical Physics and Biophysics, Estonian Academy of Sciences.  Starting from 1992 he was Research Assistant Professor at the University of Illinois at Urbana-Champaign, and at the NSF Science and Technology Center for Superconductivity before joining Bell Labs in 1998 as the Member of Technical Staff.  Dr. Blumberg is an expert in optical spectroscopy in solids, liquids and gases, single molecule spectroscopy, surface enhanced Raman spectroscopy and spectroscopic instrumentation.  He is best known for his contribution to electronic Raman scattering studies in correlated electron systems, superconductors and quantum spin systems.  He has organized numerous spectroscopy meetings and served in advisory boards of numerous national and international conferences.  He is an author in over 80 publications and is inventor or co-inventor on 18 patents in the fields of nano-plasmonic applications and spectroscopy.  He is a Fellow of the American Physical Society.