Direct observation of effects of viscosity on the picosecond lifetimes of trans-stilbene

Abstract

Using a frequency-tunable UV picosecond laser source and a synchronously operated streak camera, the solvent viscosity dependence of the fluorescence lifetime of trans-stilbene was measured. Over the viscosity range from 1.2 to 230 cP the lifetime increased from 57 to 152 ps. In addition to the short component, a much longer and weaker contribution to the fluorescence time decay was recorded.