Wave propagation in particulate media

The purpose of this project is to study optical propagation in a medium consisting of random, discrete scattering centers with a view of establishing the effects of clouds and fogs on optical communication systems. The degree of pulse stretching, power loss and beam spreading are to be determined as functions of the scattering geometry and the physical properties of the scatterers and compared with the predictions of theoretical models. An appropriate scattering medium for these experiments is an emulsion of two dielectric liquids since the indices of refraction of both the scatterers and the bulk medium can be varied by choosing different substances and the size of the droplets of the dispersed phase can be controlled by the method of preparation. In addition, emulsions can be stabilized with surfactants and can have much higher number densities than can be maintained in cloud chambers. This allows one to simulate the effect of say a kilometer of cloud in a laboratory scale scattering experiment.