Optical Near - Field Control and Nanoscale Spectroscopy using Photoemission Electron Microscopy

Datum

18.10.2011

Zeit

16:40 - 18:10

Sprecher

Prof. Dr. Walter Pfeiffer

Zugehörigkeit

Fakultät Physik, Universität Bielefeld

Serie

TUD Physikalisches Kolloquium

Sprache

en

Hauptthema

Physik

Andere Themen

Physik

Host

Walter Keller

Beschreibung

The presented work covers recent developments in the field of ultrafast nanooptics. This novel field of research not only offers a fundamental understanding of na noscale optical processes but furthermore rises interesting perspectives for future developments making use of both the large bandwidth response and the coherent phenomena which are crucial for nanophotonic devices. The combination of ultra - short laser excitation, adaptive pulse shaping and photoemission electron microscopy (PEEM) opens a new realm for the investigation of plasmonic and nanophotonic excitations. Polari¬za - tion pulse shaping, i.e. the design of ultra - s hort laser pulses with continuously changing polarization state, allows nanoscale excitation switching in the vicinity of a metal nanostructure. The locally emitted photoelectrons are monitored with PEEM down to ~50 nm spatial resolution, revealing both ad aptive control of localization and ultrafast spatio - temporal switching of the excitation. Besides excitation control the spatially recorded photoelectrons map the collective electron excitation in nanostructures via a modified 2D spectroscopy scheme. As an example long - living (150 fs) plasmonic resonances on a corrugated silver film are reported.

Letztmalig verändert: 18.10.2011, 09:36:34