Propagation of intense laser radiation through a diffusion flame of burning oil

Abstract

We report the results of measuring the absorption coefficient of radiation from a cw ytterbium fibre single-mode laser with the power up to by a diffusion flame of oil, burning in the atmosphere air at normal pressure on a free surface. For the constant length and width of the flame and the distance between the laser beam axis and the oil surface the dependence of the absorption coefficient, averaged over the flame length, on the mean radiation intensity (varied from to ) entering the flame is obtained. The qualitative explanation of nonmonotonic behaviour of the absorption coefficient versus the intensity is presented.