Linear and nonlinear optics of hybrid plasmon-exciton nanomaterials in the presence of overlapping resonances

TL;DR

This paper investigates the complex optical behavior of hybrid plasmon-exciton nanomaterials with overlapping resonances, revealing multiple resonant modes and controllable quantum dynamics for advanced nanophotonic applications.

Contribution

It introduces a detailed analysis of strong coupling effects in hybrid plasmon-exciton systems with controllable resonances and demonstrates the design of materials with Fano-type resonances using femtosecond lasers.

Findings

Four resonant modes in asymmetric configurations under strong coupling.

Three resonant modes when molecular aggregates cover the dipolar wire.

Potential for designing nanomaterials with pronounced Fano resonances.

Abstract

We consider a hybrid plasmon-exciton system comprised of a resonant molecular subsystem and three Au wires supporting a dipole mode which can be coupled to a dark mode in controllable fashion by variation of a symmetry parameter. The physics of such a system under strong coupling conditions is examined in detail. It is shown that if two wires supporting the dark mode are covered with molecular layers the system exhibits four resonant modes for a strong coupling regime due to asymmetry and lifted degeneracy of the molecular state in this case, while upon having molecular aggregates covering the top wire with dipolar mode, three resonant modes appear. Pump-probe simulations are performed to scrutinize the quantum dynamics and find possible ways to control plasmon-exciton materials. It is demonstrated that one can design hybrid nanomaterials with highly pronounced Fano-type resonances when excited by femtosecond lasers.