Turbulent phase screens generated by covariance approach and their application in numerical simulation of atmospheric propagation of laser beam

Abstract

Multiple phase screen (PS) method is typically used in numerical simulations of light propagation through a turbulent atmosphere and an adaptive optics (AO) system for phase compensation. One of key problems in it is generation of turbulent PS for describing the turbulent atmosphere. The covariance approach is a relatively new approach for generating PS. In this paper, the covariance approach is used to generate turbulent PS and a preliminary numerical simulation investigation on this approach and its generated PS is carried out. We propose to use three methods to evaluate the generated PS in a combining way. It is found that a comparison of the phase structure function of generated PS with the theoretical one is not enough and often inefficient. By contrast, a comparison of open loop and close loop laser propagation results by using generated PS can give a deeper insight. Open loop and close loop results by using PS generated by covariance approach are obtained and compared with those by using PS generated by spectral approach for the first time. It is shown that PS generated by covariance approach includes more abundant frequency components and these components have obvious influences on light propagation through a turbulent media.