"The study of photon switching and sensing mechanisms in graphene nanocomposites"

In this talk we will discuss both the one-photon and two-photon switching and sensing mechanisms in graphene hybrid nanomaterials. Hybrid nanomaterials are fabricated by combining two or more semiconductor, metallic, or biological nanostructures. By using various combinations of these nanostructures one can create enormous numbers of hybrid materials. These materials have important applications in chemical and biological sensing and optical communications and information processing. When one or more external electromagnetic fields are applied to a hybrid system, the constituent nanostructures become optically excited. The optical excitations in semiconductor nanostructures are electron-hole pairs (excitons), while excitations in graphene are collective oscillations of electrons (plasmons). The interaction of light with hybrid system can be controlled by the shape, size and relative positions of the constituent nanostructures. Therefore, these materials are an ideal platform for fundamental research on light-matter interactions and physics at the interfaces. It is expected that this research will provide a basic physical understanding and development of new types of nano-devices including optical sensors and optical switches.