Generating condition of non-diffractive beam under annular beam propagation in random media

摘要

We focused on the propagation property of an annular beam in strong scattering random media such as nimbostratus or dense fog. An annular beam as a lidar transmitted beam can propagate a longer distance even through atmospheric fluctuation. The reason is that an annular beam can self-transform to a non-diffracting beam, which is called non-diffractive effect. In this work, the center peak intensity as result of non-diffractive effect was generated after the propagation of an annular beam in random media with different concentrations and propagation distances. The linear relationship between the propagation distance and the transport mean free path calculated from the media concentration that caused the maximum center peak intensity was obtained. The generation condition of the non-diffractive beam was discussed under arbitrary parameters of beam diameter, propagation distance and media concentration.