The ethanol-water mixtures can emit fluorescence when excited by the ultraviolet (UV) light, which is different from pure ethanol and water. There are three emission bands of the mixtures and the center bands are located at 290, 305, and 330 nm, respectively. The fluorescence lifetimes of different emission bands are tested respectively: the average lifetime of 330-nm fluorescence band is about 26.5 ns, for the 305-nm emission band 2.5 ns, and for the 290-nm band 11 ns. By the spectral characteristic and the time-resolved spectroscopy one can conclude that there are several components in the solution of ethanol-water mixture.
© 2005 Chinese Optics LettersPDF Article