Bifurcations of Catastrophe Types at Change of Parameters of Thermal Nonlinearity of Media of Electromagnetic Wave Propagation

The influence of thermal nonlinearity on structure of an electromagnetic field in focal regions such as catastrophes is investigated. The numerical modeling of deformation of a wave field structure at change of a nonlinearity parameter is executed by a method of the parabolic equation in focal regions appropriate to a cuspoid singularity such as "butterfly". Bifurcations of singularities are investigated. The concept of the associated ray structure of a field is entered and the qualitative conformity of development of amplitude and ray structure of a field with increase of a parameter of nonlinearity is shown. The development of singularity (catastrophe), crushing of amplitude structure and formation of the new focal centers are investigated.