Fluorescent properties of organic molecules under high-power pulsed laser excitation

Results of the study of the intensity, the pulse length, and the emission s pectra of trans-stilbene and 2-(4-pyridyl)-5-phenyloxazole (4PyPO) excited by high-power (10(23)-10(26)) phot/(cm(2) s) radiation from an exciplex XeC l laser are presented. The anomalous increase in the emission intensity is found for ethanol solutions of 4PyPO, trans-stilbene, and the 4PyPO photoca tion in aqueous solution, and the blue (<10 nm) shift of the spectra was ob served with increasing excitation intensity. The reasons for the appearance of the special features of emission properties of the compounds studied un der high-power laser excitation are discussed.