Dresden 2006 – scientific programme
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O: Oberflächenphysik
O 43: Time-resolved spectroscopy I
O 43.1: Talk
Thursday, March 30, 2006, 17:30–17:45, WIL C207
Nanoscopic ultrafast space-time-resolved spectroscopy — •W. Pfeiffer1, T. Brixner1, C. Spindler1, and F.J. García de Abajo2 — 1Physikalisches Institut, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany — 2Centro Mixto CSIC-UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain
We analyze a recently proposed new scheme for ultrafast spectroscopy with nanometer spatial and femtosecond temporal resolution [1] that enables the direct spatial probing of nanoscale energy transfer or charge transfer processes. The interaction of polarization-shaped laser pulses with a nanostructure allows us to control the spatial and temporal evolution of the optical near-field. Employing a learning algorithm, the field is tailored such that pump and probe excitation occur at different positions. Both excitations can be restricted to sub-diffraction extensions and are separable on a nanometer length scale. Substantial control according to different goals is demonstrated and the limits of controllability are investigated. The dominating control mechanism is local interference of near-field modes that are excited with the two independent polarization components of the incident light pulses and hence polarization pulse shaping is essential to achieve substantial control in the optical near-field. The influence of other control mechanisms is discussed and a number of possible applications using different nanostructures such as planar and three-dimensional arrangements of nanoparticles are presented.
[1] T. Brixner, F. J. García de Abajo, J. Schneider, and W. Pfeiffer, Phys. Rev. Lett. 95, 093901 (2005).