Plasmonic nanoparticles, gain media and loss compensation

摘要: The resonant behaviour of single plasmonic nanoparticles in contact with gain media is studied theoretically, a focus on the issue loss compensation, resonance amplification and modification. Two approaches are presented. first description macroscopic based simple, quasi-static continuum medium, shows that gain-assisted particle display unusual responses, features depending notably nature metal used (gold or silver). Results discussed two geometries, metallic an infinite core-gain shell nanoparticles. second model microscopic describes situation gold nanoparticle, surrounded corona dye molecules nanocrystals. A full analytical electromagnetic proposed, taking into account interactions, through Green function formalism, between particle, also dye, both directly mediated via nanoparticle. modes particle-and-dye system studied, demonstrating some modes, either emissive absorptive, can be strongly amplified dominate response ensemble.