chiralFEBID - Direct writing of chiral and nonlinear plasmonic devices

• Applicant: Dr. Katja Höflich
• Subject Area: Synthesis and Properties of Functional Materials
• Term: from 2019 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 428223558

Progress in miniaturisation constitutes an enormous impetus for technical innovations in information technology, permeating all economic sectors. Future IT systems will rely on photons instead of electrons what triggers the need for nanoscale optical devices. Plasmonic nanostructures constitute a promising approach since their minimum geometric features are not restricted by the diffraction limit. This project will focus on designing, fabricating and testing of threedimensional nano-devices based on plasmonic nanostructures. The proposed devices are a chiral circular polarization converter and a chiral all-optical converter downscaling telecom light to visible light on chip by second and third harmonic generation. Polarisation sensitive waveguides will serve for in- and out-coupling from near to far-field. The envisaged footprint of the device prototypes will be smaller than 1 μm^2 constituting a crucial step towards device miniaturisation. The device fabrication requires the combination of full geometric shape control with desired material properties. In this regard direct writing with electrons is the optimum choice. While the focused electrons account for minimum structural features, the direct writing provides access to three dimensions in a single step. In combination with ionbeam based pattering complex devices can be fabricated within one vacuum chamber. Since plasmonic systems require a metallic optical response with preferably low losses, deposited and patterned materials will be optimized concerning their optical response in the visible range. Materials and devices will be characterized with various spectroscopic techniques. Numerical simulations and analytical calculations constitue the backbone of the experiments. In summary, the proposed project will establish a novel route for plasmonic device fabrication and lead to a deeper understanding of light-matter interaction at the nanoscale.

• DFG Programme: Research Grants
• International Connection: Switzerland
• Cooperation Partner: Dr. Ivo Utke