Femtosecond two-photon excited fluorescence of melanin.
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.
Teuchner
K
K
Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, Berlin, Germany. teuchner@mbi-berlin.de
Freyer
W
W
Leupold
D
D
Volkmer
A
A
Birch
D J
DJ
Altmeyer
P
P
Stücker
M
M
Hoffmann
K
K
D006801:Humans; D066298:In Vitro Techniques; D008543:Melanins / Q000138:chemical synthesis / Q000737:chemistry / Q000528:radiation effects*; D008545:Melanoma / Q000209:etiology; D010777:Photochemistry; D017785:Photons; D012867:Skin / Q000737:chemistry / Q000528:radiation effects; D012878:Skin Neoplasms / Q000209:etiology; D013050:Spectrometry, Fluorescence
D008543:Melanins