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A brief retrospective analysis of studies of fractal light radiation is carried out. To assess the prospects of this scientific direction, new original results of studying the diffraction propagation of vortex wave beams with a fractal structure (vortex diffractals) are also presented. For this purpose, computational algorithms and related software have been developed. In calculating the amplitude-phase and scaling characteristics of diffractals two-dimensional Weierstrass functions and multistructures of Gaussian beams were used. The results indicate a high information capacity of vortex diffractals and explain their resistance to the influence of turbulence in the propagation medium.

The physical nature and manifestation of several types of instabilities and fluctuation processes in the cavity of the fast-flow CO2 -laser are considered. It was established by experiment that optimal design of optical and gas-dynamic laser sections depresses totally the high frequency fluctuations and reduces low-frequency fluctuations to the level 6-10%. It was shown that inhomogeneities in the laser cavity are apt to complicate appreciably the space-temporary structure of output laser radiation. To interpret the experimental results influence of phase aberrations on the process of formation of caustics and wavefront dislocations in laser beam is considered.

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