Konstanz 1998 – wissenschaftliches Programm
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Q: Quantenoptik
Q 32: Poster IId: Laserspektroskopie
Q 32.7: Poster
Mittwoch, 18. März 1998, 16:00–18:00, PF
Fluorescence Fluctuations in fs-Pulse Interferometry - Coherence in organic Crystals — •A. Tortschanoff, K. Brunner, C. Warmuth, and H. Kauffmann — Inst. f. Phys. Chem., Univ. Wien, Waehringerstr.42, 1090 Wien
Monitoring the quantum interference fluctuations in the excited- state population by a pair of time-delayed, phase-randomized pulses, allows to interrogate internal dynamics, energy level splittings, and characteristic coherence decay times of the medium. Thus, the analysis of the variance of the stochastic spontaneous fluorescence as, previously, reported for atoms can provide valuable information about coherent transients (Coherence Observation by Interference Noise [1]). We have applied COIN-spectroscopy to study fs coherence phenomena in pentacene-p-terphenyl mixed crystals at 4.3 K using a Ti/S-regenerative amplifier-OPA configuration to produce tunable pulses and allow to excite all four long-wavelength S0→ S1transitions in the O1-O4 pentacene site-array, in addition to several vibrational levels of a specific site. The analysis of the fluorescence interferences (excitation oscillations) and their damping patterns reveals novel inter- and intramolecular interaction and relaxation pathways.
[1] O. Kinroth et al., Phys. Rev. Lett. 75, 3822 (1995)