Two-photon absorption and laser photochemical decomposition of trans-stilbene substitutes

摘要

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 ((gamma)~(266)) 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 S_(1)-S_(n) 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.