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Q: Quantenoptik und Photonik
Q 40: Laserspektroskopie
Q 40.8: Vortrag
Donnerstag, 25. März 2004, 18:15–18:30, HS 204
Investigation of photosynthetic processes by picosecond fluorescence spectroscopy — •Franz-Josef Schmitt1, Hans Joachim Eichler1, Hann-Jörg Eckert2, and Joachim Huyer1 — 1Optisches Institut - P 1-1, Technische Universität Berlin, Strasse des 17. Juni 135, D-10623 Berlin — 2Max-Volmer-Laboratorium, Technische Universität Berlin, Strasse des 17. Juni 135, D-10623 Berlin
The primary processes of photosynthesis in higher plants and Cyanobacteria start with the generation of excited states by light absorption within pigment-protein complexes forming the antenna system (mainly Chlorophyll molecules). The electronic excitation then migrates via singlet-singlet energy transfer to the reaction center where it induces a primary charge separation leading to a primary radical pair (P+A-). Information on these processes can be gathered from analyses of the dynamics and wavelength dependence of the emitted fluorescence. Both can be obtained in short acquisition times by using a novel single photon counting fluorometer system which permits to monitor simultaneously the time and wavelength dependence of the fluorescence emission. The key element of this equipment is a special microchannel-plate photomultiplier with delay-line anode. The data are recorded by a two-dimensional multi-channel-analyzer on the basis of a computer system. In this report we compare the time resolved fluorescence spectra of various photosynthetic organisms with different Chlororophyll types (Chl a, Chl b, Chl d) in the antenna system.