A study of refraction of a cylindrical laser beam in stratified liquid

Refraction of a cylindrical laser beam in a transition layer at the interface of two liquids with different optical characteristics is studied theoretically and experimentally. A theoretical basis for calculations of the beam trajectory in the transition layer of stratified liquid is given. Two- and three-dimensional images (2D and 3D refractograms) of a cylindrical laser beam inside and outside the media are obtained on the basis of a tangential model of the refractive index profile. The influence of the parameters of the laser beam and media on the appearance of refractograms is studied and the optimal experimental conditions are selected with the use of computer simulation. A scheme of the setup for recording digital 2D refractogram and experimental results are presented. Algorithms for digitizing experimental images and for their comparison with calculated refractograms to determine the refractive index profile in the transition layer based on the tangential model are developed.