Femtosecond Two-photon Excited Fluorescence of Melanin* |
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| Authors: | Klaus Teuchner Wolfgang Freyer Dieter Leupold reas Volkmer David J. S. Birch Peter Altmeyer Markus Stucker Klaus Hoffmann |
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| Affiliation: | Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, Berlin, Germany. teuchner@mbi-berlin.de |
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| Abstract: | Fluorescence of synthetic melanin in dimethyl sulfoxide has been excited by two-photon absorption at 800 nm, using 120 fs pulses with photon flux densities > or = 10(27) cm-2 s-1. The shortest main component of the three-exponential decay of fluorescence is 200 +/- 2 ps. The overall spectral shape is red-shifted with respect to the 400 nm excited fluorescence. Two-photon excited melanin fluorescence also has been measured from excised samples of healthy human skin tissue. Because of the selectivity of melanin excitation via resonant two-photon absorption, it is hypothesized that fluorescence excited in this way may yield information on malignant transformation. |
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