Amplification and Lasing of Plasmonic Modes

Plasmonic modes provide the potential for routing information with optical speeds and bandwidth at the nanoscale. The inherent tradeoff between modal energy confinement and energy dissipation, however, makes realizing this potential an extreme challenge. For decades, researchers have investigated compensating losses in plasmonic systems with active gain media. In recent years, progress has increased dramatically, as nanoscale plasmonic amplifiers and lasers have emerged. We review this progress and offer our prospective on the challenges ahead.