Photoinduced Mass Transport in Liquids

Optically induced changes in the concentration distribution of Fluorescein and DCM dye solutions were investigated, with their dependences on the laser intensity and optical properties of solvent examined. In the experiments we used a thin solution layer (~70 μm) between two glass plates, which was exposed to CW laser radiation (γ = 523 nm). Under intensive laser illumination a transport of dissolved dye was observed. The distribution of solution concentration was analyzed using a low-intensity CW laser focused beam. The spectroscopy methods were employed to reveal differences between the absorption spectra of the solution before and after exposure. The solution concentration was proved to change around the exposed spot.