Strong Exciton–Plasmon Coupling in Waveguide‐Based Plexcitonic Nanostructures

• Published in: physica status solidi (b) 2020-12, Vol.257 (12), p.n/a
• Main Authors: Mahinroosta, Tayebeh, Mehri Hamidi, Seyedeh
• Format: Article
• Language: English
• Subjects: coupled-resonator optical waveguides; finite difference time domains; plexcitonic structures; Rabi splitting
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.202000266

A new 2D plexcitonic structure based on coupled‐resonator optical waveguides is demonstrated to enhance light–matter interactions in the J‐aggregate molecules coupled to the plasmonic resonator. For this purpose, four different plexcitonic structures are defined by adjusting the coverage of dye medium over the plasmonic structures and applying forward or backward illumination direction, which are examined by the finite difference time domain method. The results show that several parameters could be used to sweep plasmon–exciton coupling in the weak, intermediate, and strong coupling regimes such as the type of structures (single or array of nanodisks), the radius of nanodisks, the direction of the incident light, and the concentration of J‐aggregate molecules. From the presented results, there are remarkable values for Rabi splitting by tuning these parameters, and it is achieved that the sample with coverage of dye in the style of the plasmonic pattern in backward illumination offers higher strength of the plasmon–exciton coupling, and then Rabi splitting is about 670 meV for the radius set to 90 nm. This amount of splitting in this new kind of plexcitonic structure can open new insight in low cost and efficient hybrid structures. Herein, the purpose is to examine the weak, intermediate, and strong exciton–plasmon coupling regimes in waveguide‐based plexcitonic nanostructure by varying the type of structures (single or array of nanodisks), adjusting the coverage of dye medium over the plasmonic structures, the radius of nanodisks, the direction of the incident light and the concentration of J‐aggregate molecules by finite‐difference time‐domain method.