At Paderborn University’s New Year’s reception on 18 January 2015,the University Society awarded Franziska Zeuner the prize for outstanding final-year projects for the academic year 2013/2014 in the category of Engineering and Natural Sciences for her master's thesis on the coherent control of localised surface plasmons. “Withthe results of her measurements, she was able to impressively demonstrate the control of plasmonic resonances on the nanoscale through coupling effects between small optical antennas,” explains Prof. Dr Thomas Zentgraf, head of the Ultrafast Nanophotonics research group: “These findings represent a further step towards nanoscale components and logical operations using light.”
In her master's thesis, M.Sc. Franziska Zeuner investigated a system of plasmonic nanostructures with regard to their near-field coupling and the possibility of selectively exciting or de-exciting individual structures using light. To this end, she examined the non-linear optical properties of this structure as a function of the excitation light, which consisted of ultrashort laser pulses of varying polarisation and phase. “This required a high degree of experimental skill and a deep understanding of the underlying techniques,” says Prof. Dr Thomas Zentgraf, who supervised her master's thesis together with Prof. Dr Christine Silberhorn and in whose research group she has been working as a PhD student since October 2014.
As the non-linear optical signals are very weak and require long measurement times, the experiments and the recording of measurement data were fully automated. Subsequently, the use of numerical simulation tools and an analytical model enabled the results to be visualised and evaluated. In this way, Ms Zeuner was able to gain a better understanding of the non-linear optical properties of the coupled system, which consisted of three individual nanoscale gold antennas.
