Study of nonlinear optical absorption and optical sideband generation in a hybrid plasmonic nanoparticle-quantum dot-DNA system in the presence of two optical fields

Mina Abbasi Moghaddam; Nader Daneshfar

doi:10.1038/s41598-025-08643-6

Study of nonlinear optical absorption and optical sideband generation in a hybrid plasmonic nanoparticle-quantum dot-DNA system in the presence of two optical fields

Sci Rep. 2025 Jul 3;15(1):23685. doi: 10.1038/s41598-025-08643-6.

Authors

Mina Abbasi Moghaddam¹, Nader Daneshfar²

Affiliations

¹ Department of Physics, Faculty of Science, Razi University, Kermanshah, Iran.
² Department of Physics, Faculty of Science, Razi University, Kermanshah, Iran. ndaneshfar@razi.ac.ir.

Abstract

In the present work, we theoretically/numerically study the optical second-order sideband generation in a hybrid structure consisting of a semiconductor quantum dot (QD) conjugated with DNA molecules, and coupled to a solid metallic nanoparticle (MNP) or a metallic nanoshell (MNS) with core-shell geometry. The hybrid system is driven by a strong control (pump) laser field and a weak signal (probe) field. The dynamics of the system is analyzed using the Heisenberg equation of motion in the frame of rotating wave approximation. We discuss the role of plasmon-exciton interaction in enhancing third- and fifth-order nonlinear susceptibilities through the nonlinear optical response of the system and the effects of the presence of a MNP or a MNS near the QD-DNA system on the nonlinear optical absorption spectrum is investigated. We demonstrate that the second-order sideband is generated, and the hybrid system considered here enables robust control and tunability of the second-order sidebands. It is shown that the second-order sideband spectrum (or absorption) is significantly affected by plasmonic nanoparticle size, the interparticle distance, the control field (Rabi frequency ), and the control-exciton detuning.

Keywords: Hybrid system; Nonlinear absorption; Sideband generation.