Lasing action in active plasmonic structures

We present our recent advances in nanoscale lasing action enabled by plasmonic resonances. First, we study lasing action in plasmonic crystals incorporating optically pumped four-level gain media. We show that the excitation of dark plasmonic resonances (via the gain medium) enables accessing the optimal lasing characteristics of this class of systems. Second, we analyze the conditions for the emergence of self-sustained laser oscillations in an optically-pumped long-range surface-plasmon structure that includes plasmonic Bragg mirrors as optical feedback mechanism.