PhD final seminar Light-matter Interaction in Nanowire Systems
During my PhD I focused on optical properties of nanowires made of different materials with internal structuring. For this purpose, I have developed novel techniques to control the light matter interaction. In my final presentation, I will discuss two complementing approaches: (i) a semi-analytical method to analyze the scattering and absorption of light with single or interacting, and linear or nonlinear nanowire systems, and (ii) a genetic optimization algorithm, employing the semi-analytical fast solution to search for optimal set of designing parameters. Then, regarding to importance of scattering and absorption of light by nanostructures, I will discuss the control of these phenomena in nanowire systems and engineering them in their extreme regime. In particular, tuning of scattering properties, such as, invisibility cloaking and superscattering will be discussed as two extreme cases. Enhancing the absorption of light on the other hand, improves the efficiency of lots of optical devices which in its extremum case, it can cause superabsorption effect.
By bringing more nanowires together to construct more complicated systems, the coupling between the nanowires and multiple scattering problems should be also considered. We will discuss how scattering control in such systems can lead us to manage electric and magnetic hotspots in nanowire dimer systems. Finally I will present how we can manage scattering and absorption of light in a complex nanowire structure to electromagnetically shield nun-isolated areas and block the light propagation through spaced nanowires.
Beyond linear regime, nonlinearity in multilayer nanowires will be also discussed through our novel analytical recipe to investigate nonlinear properties of nanowires and their optimization with some examples. This approach is more than 10^5 times faster than FDTD in analyzing nonlinear systems.