Le séminaire Nanoplasmonics with Ultrafast Transmission Electron Microscopy se déroulera en anglais seulement.

Bienvenue à tous!

Professor Aycan Yurtsever
Institut National de la Recherche Scientifique (INRS)

Localized electric fields that are induced optically exhibit unique phenomena of fundamental importance to nanoplasmonics. In recent years, they have been considered for efficient photovoltaic and light harvesting devices, single molecule detection, biomolecular labeling and manipulation, and surface enhanced Raman scattering. Success has been made in developing experimental tools to probe the effect of their presence, but it remains difficult to directly and robustly image the optically induced near-fields, both in space and time. In this seminar, I will introduce a novel imaging methodology that can directly map the near-fields of nanoplasmonics with spatiotemporal resolutions that were not possible before. Ultrafast transmission electron microscopy (UTEM) enables the direct visualization of the electric fields as they rise and fall within the duration of the excitation laser pulse (few hundreds of femtoseconds) with nanometers of spatial resolution. This imaging approach is based on an inelastic photon-electron interaction process, where the probing electrons gain energy equal to the integer multiple of the photon quanta (2.4 eV in these experiments). I will elaborate this fundamental scattering process in my talk. Furthermore, I will discuss images, and movies, of the near-fields of particle dimers, nanoparticles with different sizes and shapes, particle ensembles and standing-wave plasmons at the step edges of graphene strips.


Dr. Yurtsever is an Associate Professor at the Énergie Matériaux Télécommunications Center of INRS. He holds a Canada Research Chair in Ultrafast Dynamics of Nanoscale Systems. He received his Ph.D. from Cornell University under the supervision of Prof. David Muller. His post-doctoral appointment was in the group of Prof. Ahmed Zewail (Nobel Laureate in Chemistry) at the California Institute of Technology. There he made significant contributions to the development of advanced imaging methodologies using ultrashort electron and laser pulses. His current research interests include non-equilibrium structural dynamics, ultrafast energy transfer and non-linear optical processes at the nanoscale. He frequently communicates his research results in prestigious journals, such as Nano Letters, PNAS and Science.