The two-photon absorption (TPA) cross section of an ethanol solution of of three molecules (a trans-stilbene and its derivatives) exposed to radiation of the second harmonic of a Nd:YAG laser (532 nm) of nanosecond duration has been determined using the method based on the measurement of the photochemical decomposition of examined molecules, characterized by a low photostability. The quantum yield of the photoreaction (γ²⁶⁶) of dyes under one-photon excitation (4^-th harmonic Nd-YAG laser 266 nm) was preliminary determined by absorption method. Then photochemical decomposition of molecules was investigated at two-photon excitation TPA cross-section was determined. At definition of TPA cross-section of molecules, influence transient S₁-Sn absorption was taken into account. Comparison of values of TPA cross-section determined in the work, with the experimental and theoretical data received by other authors for these molecules were carried out.

Date Published: 9 July 2007
PDF: 11 pages
Proc. SPIE 6727, ICONO 2007: Nonlinear Laser Spectroscopy and High-Precision Measurements; and Fundamentals of Laser Chemistry and Biophotonics, 67271E (9 July 2007); doi: 10.1117/12.752364

Published in SPIE Proceedings Vol. 6727:
ICONO 2007: Nonlinear Laser Spectroscopy and High-Precision Measurements; and Fundamentals of Laser Chemistry and Biophotonics
Sergey A. Tikhomirov; Maxim S. Pshenichnikov; Thomas Udem; Oleg M. Sarkisov; Valery Yudin, Editor(s)