Reversal of the wavefront of the second harmonic of YAG laser radiation used in atmospheric sounding

An analysis was made of reversed second harmonic radiation of a YAG laser traveling opposite to radiation probing an inhomogeneous medium (static and dynamic model media, turbulent atmosphere). The characteristics of the recorded radiation (angular spectrum, dispersion of the intensity fluctuations) are compared with the case of specular reflection and wavefront reversal without a change in the optical frequency.