New Publication in Nano Letters
The CFEL-ATTO team was part of an international collaboration between DESY, Stanford University, the Max-Planck Institute of Quantum Optics (MPQ) and the University of Hamburg, for which the results on plasmonic field sampling have just been published in Nano Letters. In this work we report the direct sampling of an emerging plasmonic field on the petahertz scale, using a technique which allows to characterize an electric field directly in the time domain with subcycle resolution. The observations may lead to new insights in the fields of nanophotonics and energy conversion.
An ultrashort laser pulse (blue) excites plasmonic nanoparticles (e.g. gold nanorods), which leads to characteristic changes in the transmitted electric field (yellow). Sampling this field at frequencies reaching the petahertz domain permits to infer the plasmonic field of the nanoparticles with attosecond precision. Image credit: RMT.Bergues.
Abstract: The response of metal nanostructures to optical excitation leads to localized surface plasmon (LSP) generation with nanoscale field confinement driving applications in, for example, quantum optics and nanophotonics. Field sampling in the terahertz domain has had a tremendous impact on the ability to trace such collective excitations. Here, we extend such capabilities and introduce direct sampling of LSPs in a more relevant petahertz domain. The method allows to measure the LSP field in arbitrary nanostructures with subcycle precision. We demonstrate the technique for colloidal nanoparticles and compare the results to finite-difference time-domain calculations, which show that the build-up and dephasing of the plasmonic excitation can be resolved. Furthermore, we observe a reshaping of the spectral phase of the few-cycle pulse, and we demonstrate ad-hoc pulse shaping by tailoring the plasmonic sample. The methodology can be extended to single nanosystems and applied in exploring subcycle, attosecond phenomena.
The publication can be found here.
Official news link: https://www.cui-advanced.uni-hamburg.de/en/research/wissenschaftsnews/24-05-08-plasmonics.html