Plasmonics, the science of coupled states of light and charge density waves, is nowadays a very broad field of research. Electromagnetic fields confined to small volumes near metal surfaces enhance many other physical effects that emerge from the interaction of diffraction limited electromagnetic fields with matter, e.g. imaging, Raman-Spectroscopy or Faraday rotation. However, these effects are strongest, when the plasmonic resonator is optimized for the desired task. How to design these nano-optical devices is at the heart of my own research.
I’m interested in the fundamental working principles of plasmonic resonators. I strove the last years toward an understanding of how the mode currents of a plasmonic resonance impact its functionality. I framed a three-dimensional double mode-matching formalism and to optimize an optical antenna to efficiently transduce the energy stored in a single emitter to far-field radiation.
My actual research goal is to expand this method to understand and optimize the chiral and/or non-linear response of plasmonic nano-structures. Both topics have a bright future in sensing applications and I strive to develop fundamental design rules for optimal devices.
In a second research branch I try to learn as much as possible about the interplay of voltages applied to plasmonic nano-structures and their resonant behavior.
The methods I use to achieve my goals contain analytical calculations based on numerical results acquired by Finite-Difference-Time-Domain Simulations which are often driven by optimization methods like evolutionary algorithms or particle swarm optimization. Finally I use SPM and confocal microscopy to characterize the optimized geometries, which I fabricate by means of focused ion beam milling from monocrystalline gold flakes.