Intensity fluctuations of pulsed laser radiation during thermal self-interaction in a turbulent medium

Theoretical and experimental investigations are reported of the spatial spectra of intensity fluctuations of laser radiation propagating through an absorbing turbulent medium. It is shown that during propagation of spatially coherent radiation, thermal nonlinearity initially damps and then amplifies the intensity fluctuations. Deterioration of the coherence reduces both the relative intensity fluctuations and the nonlinear effects.