Authors: A.Y. Smuk and N.M. Lawandy
Affilation: Solaris Nanosciences Corporation, United States
Pages: 646 - 648
Keywords: plasmon resonance, nanostructures, amplifying medium
Numerous applications that rely on the local field enhancement associated with the Surface Plasmon Resonance (SPR) have been suggested. With host material being an integral part in forming SPR, systems with optically transparent host have been studied exhaustively, while the case of an absorbing host still generates discussions in the literature. Amplifying host in the context of SPR has until now received no attention in the literature. This paper considers the problem of resonant scattering of electromagnetic radiation by small metallic particles embedded in amplifying medium. A recent theoretical analysis showed for the first time that the presence of gain in the host medium could result in a considerable enhancement of the SPR of colloidal metals in that host. Local field intensities can be enhanced by as much as two orders of magnitude, compared with those obtained near surface plasmon resonance of metal nanoparticles in non-amplifying media. We further develop these ideas in a rigorous manner as a generalized Mie solution. We also show that certain core-shell and non-spherical geometries lead to reduction in gain requirement. Possible applications for these systems include rapid single molecule detection for gas and biological sensors and ultra-low intensity optical tweezers for manipulation of nanostructures.