Theoretical And Experimental Study Of Inhomogeneous Pseudo-Scherm-correlated Partially Coherent Beam

In recent years,the correlation function has received extensive attention because it directly determines the propagation behaviors of the beam.The correlation function control provides a new idea for the control of the propagation characteristics of the beam,and has important applications in particle control,material processing,optical imaging,and freespace optical communication.In this paper,the theoretical structure and experimental methods of non-uniformly correlated partially coherent beams have been deeply studied,and the partially coherent beams carrying both twist phase and non-uniformly correlated structure have been studied.The main research contents of this paper are as follows:Firstly,a promising approach for arbitrary shape light beams employing source coherence is introduced.A class of non-uniform Gaussian cosine pseudo Schell-model correlated beams with circular coherence has been theoretically constructed and experimentally generated,and the effects of various optical parameters of the source plane on the beam propagation characteristics are also studied in detail.The study found that this kind of beam has a remarkable anomalous self-focusing phenomenon during propagation,which is irrespective of the phase and the coherence parameter;the tunable light intensity distributions are accurately derived by simply controlling the coherence parameter,such as Gaussian,flat-topped and donut-shaped light intensity distribution.The result presents a bright prospect for manipulating light using source coherence.Secondly,this paper constructs a new class of non-uniformly correlated twisted pseudoGaussian Schell-model beam by sticking a Schell-model correlation function.Analysis shows that the initial degree of coherence of this class of beam is neither shift invariant nor shift-circular symmetric.The study found that this kind of beam not only has a rotation effect caused by twist phase but also appears a strong self-focusing bright spot in the center of the beam induced by pseudo-Gaussian Schell coherent structure during propagation.In the presence of a vortex phase,the two different types of chiral phases affect each other and together control the propagation behavior.In addition,this kind of twisted beam with nonuniform correlation structure has been generated experimentally by using pseudo-modes sampling superposition method.The result will provide new ideas for the devising twisted beams with more complex non-uniform correlation structures.