Amplified emission and lasing in a plasmonic nanolaser with many three-level molecules

Abstract

Steady-state plasmonic lasing is studied theoretically for a system consisting of many dye molecules arranged regularly around a gold nano-sphere. A three-level model with realistic molecular dissipation is employed to analyze the performance as function of the pump field amplitude and number of molecules. Few molecules and moderate pumping produce a single narrow emission peak because the excited molecules transfer energy to a single dipole plasmon mode by amplified spontaneous emission. Under strong pumping, the single peak splits into broader and weaker emission peaks because two molecular excited levels interfere with each other through coherent coupling with the pump field and with the dipole plasmon field. A large number of molecules gives rise to a Poisson-like distribution of plasmon number states with a large mean number characteristic of lasing action. These characteristics of lasing, however, deteriorate under strong pumping because of the molecular interference effect.

A Superradiant Maser with Nitrogen-Vacancy Center Spins

“…To simplify the notation, we describe the two mostrelevant spin states |0 and |−1 as the up and down components of a pseudo 1/2-spin, and we model the pumping by optical excitation and optical decay by an effective transfer rate from the state |−1 to |0 . While this treatment of the pumping is often adopted in laser theories [8,13], it can be readily extended to include intermediate states [15,16]. Accounting for the dissipation of the microwave resonator and the NV − spins, we obtain the following master equation for the reduced density operator ρ of the system:…”

Magnetic Field-controlled Transmission and Ultra-narrow Superradiant Lasing by Dark Atom-light Dressed States

“…We might solve Eq. ( 1) exactly with the density matrix in the collective number basis [11], which however requires a demanding computational effort and is thus limited to tens of atoms. To simulate the system with tens of thousands of atoms as encountered in the experiment, we rely on second-order mean-field theory.…”