Nonlinear Time-Frequency Analysis of Laser Beam Intensity Fluctuations
I. Arsenyan, M. I. Babanina, N.
A. Soukhareva, A. P. Sukhorukov
Moscow State University, Physics Faculty
July 26, 2013
Abstract. Nonlinear time-frequency
analysis was applied to the intensity fluctuations of a laser beam propagated
through the model turbulent path. For this purpose the Wigner-Ville mapping
of intensity distributions and their first four spatial moments were used. The
characteristics of time-frequency maps corresponding to different modes of
propagation channel are discussed as well as anisotropy and temporal scales of
intensity fluctuations. The experiments on the model path revealed astigmatic
distortions of the beam caused by the wind load and thermal lens defocussing.
Keywords: turbulent media,
Wigner-Ville mapping, laser beam distortions, astigmatic distortions, FSO.