A great number of problems of modern optics need to record a map of the polarization distribution in a light
beam in a real scale of time. At the same time, the conventional ellipsometric techniques  do not permit us to solve
these tasks. It stimulates development of new approaches for
measuring polarization states at each point of an optical image
[2,3]. The obtained polarization maps are a good instrument for
studying evolution of polarization singularities.
The aim of this article is to analyze evolution of
polarization singularities in radiation emitted from a 12-modes
circular optical fiber under different conditions of its excitation.