An array of QDs on a one-dimensional periodic structure of graphene nanoribbons as a nanoscale plasmonic grating

This work focused on developing nanoscale plasmonic gratings and photonic crystals using unique quantum structures, specifically Graphene nanoribbons and PbSe quantum dots, within a metal-dielectric-metal (MIM) multilayer waveguide structure. These structures are designed to operate at a wavelength of 1550 nm and exploit the interaction between electromagnetic waves and free electrons to excite surface plasmon polaritons (SPPs) to create unique optical susceptibility for the nanostructures considering the possibility of control of the chemical potential of the Graphene nanoribbon. The primary goal of this research is to create nanoscale optical devices based on photonic crystals with improved capabilities by incorporating plasmonic structures, such as Graphene nanoribbons and PbSe quantum dots, to manipulate light at the nanoscale. These are sheets of graphene with specific dimensions (775 × 40 nm²) that are bonded to a SiO₂ platform. An array of PbSe quantum dots with a radius of 10 nm is placed on the nanoribbons. This waveguide structure is used to confine and guide electromagnetic waves. The system operates at a wavelength of 1550 nm, which is within the optical telecommunication band. The nanostructure interacts with incident electromagnetic waves, exciting surface plasmon polaritons (SPPs) within the MIM waveguide. This excitation induces polarization in the PbSe quantum dots, leading to changes in the amplitude of the incident wave. The induced dipoles in the quantum dots result in a unique optical susceptibility for the nanostructure. This susceptibility depends on the geometry and optical constants of the materials used in the structure. The research aims to provide a foundation for using these nanostructures in photonic crystal-based optical devices in the future. These devices may have applications in various fields, such as telecommunications, sensors, and integrated photonics. Overall, this work focused on harnessing plasmonic and quantum properties to develop advanced nanoscale optical components, and the results could have implications for the development of next-generation photonic devices.