Berlin 2001 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 16: Poster: Dynamics of Molecular Systems, Polymer Dynamics, Glass Transition, Crystallization, Electronic Properties of Polymers
CPP 16.35: Poster
Montag, 2. April 2001, 12:30–15:00, AT1
Memory effects during the light-induced poling of photonic polymers — •Michael Lindner1, Simona Bauer-Gogonea1, Siegfried Bauer1, and Werner Wirges2 — 1Applied Physics, Johannes-Kepler University, Linz, Austria — 2Institute of Physics, Applied Condensed-Matter Physics, University of Potsdam
Photonic polymers with amorphous molecular chromophore molecules are currently under investigation for optical data storage systems. Under illumination with light, the chromophores undergo trans-cis-trans isomerization cycles, accompanied with a change of the local free volume around the chromophores. With dipolar chromophores, an additionally applied electric field allows for a noncentrosymmetric orientation of the chromophores, as a result of the enhanced mobility of the chromophores (photo-induced poling PIP). The locally enhanced free volume around the chromophores induces memory effects, that allow for poling even several hours after switching off the pump light which drives the isomerization cycles (memory poling). The stability of PIP and the magnitude of the memory effects can be influenced by poling at elevated temperatures. Second-harmonic generation experiments during and after photo-induced and memory-poling are interpreted in the frame of a local free volume model. Work supported by the FWF.