Evolution properties of array laser beams through an atmospheric turbulence and shock-wave layer

In this manuscript, a numerical model of laser array beams propagation through both turbulent atmosphere and shock-wave layer is built. We have calculated the evolution properties of seven coherent laser beams projecting to a plane hypersonic target vertically. We utilize the angular spectrum propagation method with fast Fourier transform algorithm to simulate beam propagation through turbulent atmosphere. To the propagation through shock-wave layer, we first generate the density field and the refractive index field using dual-temperature model and Gladstone Dale formula, respectively. Then the corresponding optical path length and phase screen can be obtained. By analyzing simulated results, we find that the optical intensity distribution before and after through the shock-wave layer are almost the same but the phase distribution differences are significant and decreases almost linearly along the hypersonic flow direction. The phase difference indicates that the shock-wave layer will import a tilt aberration for the optical detection system installed in the hypersonic target.