Laser Fourier imaging of chemical reaction. Observation of the diffusion process of heat emitted from dye molecules by striped laser excitation
Excitation of Eosin Y in ethanol solution with irradiated stripes of chopped argon ion laser beam gives thermal fringes which diffract helium-neon laser beam; the resulting diffraction fringes correspond to the Fourier transformation of the thermal fringes. By following the growth and decay of the transient diffraction signals the diffusivity of heat evolved by the photoexcitation in the solution was determined.