Secondary radiation in aqueous media with excitation by a pulse-periodic ultraviolet laser

Abstract

Spectra of secondary radiation (Raman scattering and photoluminescence) of water, aqueous solutions, and suspensions under excitation by a pulse-periodic ultraviolet laser are studied. Both bands associated with intramolecular and intermolecular vibrations of water and the characteristic photoluminescence bands of the corresponding chromophore groups are found to manifest themselves in the secondary radiation spectra under excitation of aqueous solutions of various aromatic compounds by the second harmonics of a copper-vapor-laser radiation. It was shown that traces of aromatic compounds present in water as well as microorganisms in it can be revealed from the form of the secondary radiation spectra. When using delay, the photoluminescence spectrum takes a number of characteristic maxima. This circumstance can be used for identification of the type of microorganism studied.