<title>Distortions of laser beams by turbulent aero-engine jet: experiment and numerical modeling</title>

Abstract

The experimental studies of spatial characteristics for laser beams disturbed by a turbulent aero-engine jet were carried out. The angular divergence, random wanderings of the beam's centroid and statistical characteristics of stochaistic intensity distribution in cross-section of laser beams with radiation wavelengths of 1.06 and 0.53 microns were determined for different angles of the beam-jet intersection. On the basis of Monte-Carlo method a numerical mathematical model for lasre beam propagation through a turbulent jet of aero-engine has been designed. The model describes experimentally detected features beyond the framework of the standard model of a turbulent layer: strong dependence from radiation wabelength and spatial anisotropy of the distorted beam's statistical characteristics. A numerical simulation experiment, verification and adjustment of the designed beam propagation model for a following comparison of results obtained from full-scale and simulation experiments were carried out. With allowance for inevitable errors of measurements and calculations, there is a good agreement between almost all statistical characteristics of disturbed laser beams obtained in different configurations during full-scale and imitative experiments.