Visible enhanced scattering from air flow turbulence

The scattering of visible laser light out of a jet of air has been investig ated in an unprecedented range of scale and intensity variations. By explor ing the scattering light intensity angular distribution, the turbulent air jet form factor has been measured continuously from unity to a value of ord er 10(12). Four different length scales and physical phenomena are observed successively: from incoherent scattering out of molecular motion at 5 mum scale, to enhanced scattering at the dissipative scale ( 5-50 mum), then at the inertial range (50-800 mum) where a universal scaling of the Kolmogoro v class is found, and finally at the production scale. The scattered intens ity is large enough to be visible and pictures of turbulence are shown at d ifferent laser wavelength.