Potentiality and peculiarity of ellipsometry in the surface studies of liquids

This paper is reported on the procedure of solving the inverse problem of ellipsometry respectively to all the parameters of the surface structure and volume of liquids. The inverse problem is mathematically incorrect due to a weak optical contrast between surface and volume of a liquid. In order to solve the problem, a trial function is introduced. The most general expression for the function is obtained. The optimal solution of the inverse problem is found through an analysis of the trial function peculiarities appearing along the trajectory of the movement of the functional of the inverse problem to the point of the absolute (the deepest) minimum. The stability of the functional movement trajectory is achieved by a specific selection of the starting point on the trajectory. General patterns of the trial function's behavior are found for an ideal situation, as well as for a real situation through a numerical simulation. It is shown that the optimal solution obtained with the trial function is highly accurate.