Second harmonic generation in a plexcitonic system comprising a quantum dot coupled to a reduced-symmetry plasmonic nanoparticle

This paper theoretically investigates the nonlinear optical response of a heterodimer composed of a semiconductor quantum dot (QD) coupled with an eccentric metallic nanoshell that is commonly known as a nanoegg (NE). We study the SHG as the most common nonlinear optical process in a hybrid QD-NE system within the framework of the density matrix approach. We show that the presence of a nonconcentric plasmonic core–shell nanoparticle in the proximity of a quantum dot strongly affects the intensity of the second harmonic signal emitted by the quantum dot. In addition to the effect of the pump field intensity, the impact of the core offset, which is a result of the displacement of the center of the core from the shell of the nanoegg structure, on the second harmonic intensity of QD in the plexcitonic NE-QD system is shown and discussed. We also demonstrate how the size of the NE core and the shell thickness strongly affect the SHG intensity. • Study of optical second harmonic generation from a quantum dot coupled to a metallic nanoegg. • The dependence of the intensity of the second harmonic signal on the nanoegg core offset and its composition is studied. • The impact of the shape and geometry of metallic nanoparticle on the intensity of the second harmonic signal is shown.