Optical amplification of surface plasmon polaritons: review

Optical amplification of surface plasmon polaritons has been pursued extensively in recent years. However, few currently known optical gain materials can be expected to provide sufficient gain to fully compensate propagation losses of highly confined surface plasmon polaritons. Low-loss plasmonic waveguide geometries, on the other hand, provide a platform for realizing net plasmon gain by sacrificing some plasmonic properties. In search for potential applications for amplified surface plasmon polaritons, focus should be on making use of both optical gain and optical loss, such as in high-extinction-ratio modulators or parity-time symmetric devices. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.JNP.6.061801]