  Spatio-temporal control of ultrafast plasmon resonances has gained research
interest in recent years because of their tremendous implications in nonlinear
optics and ultrafast quantum technology. In particular, the lifetime of
ultrashort plasmon oscillations has become a debatable subject in recent
experimental and theoretical studies to fulfill the future challenges
concerning their effective employment in the vast applications of the plasmonic
industry. Here, we examined the temporal properties of nonlinear plasmonic
modes in metal nanostructures by interacting them with quantum objects in the
weak coupling regime in order to distinguish it from the fundamental plasmonic
mode. First of all, we present an analytical description of nonlinear ultrafast
dynamics of localized surface plasmon resonances when the second harmonic
plasmon mode interacts with long-lived dark mode or quantum emitter. Later, the
coupled plasmonic system is realized in two different ways to control the
lifetime of second harmonic mode by coupling, i) driven mode to dark mode (or
long lifetime quantum emitter) ii)itself to dark mode (or long lifetime quantum
emitter). The driven-dissipative dynamics are solved through a numerical
technique governing the spatial and temporal changes in the second harmonic
plasmonic response supported by AuNP. Finally, the lifetime enhancement of
nonlinear plasmon mode is manifested by performing FDTD simulations for a
nonlinear plasmonic system of Au nanoparticles coupled with a long lifetime
quantum emitter.

Optics;Applied Physics