The Propagation Properties Of The Partially Coherent Crescent-like Beams In The Turbulence

Currently,the propagation properties of the beam in the turbulence have been widely researched.The partially coherent beams(PCBs)have unique advantages over fully coherent beams in overcoming the negative effects of turbulence when propagating in the turbulence,and the PCBs have been widely concerned by many scholars.Recently,the PCBs with non-traditional correlation structures exhibit a series of unique propagation properties when propagating in random media,such as self-splitting,self-focusing,self-drifting,self-shaping,etc.Therefore,the PCBs with special correlation functions have been widely studied.In this paper,we study the propagation properties of the PCCL beams with a special spatial structure in turbulence.Based on the non-Kolmogorov spectral turbulence and marine turbulence models,the influence of turbulence on the beams’ quality is explored numerically.The PCCL beam is advantage in travelling around an obstacle,thus,we would like to study the off-axis distance of the PCCL beams’ intensity maximum.Those results are of significance for studying laser’s propagation properties.The main content is as follows:The research backgrounds of turbulence and PCBs are introduced.We list several different kinds of refractive-index power spectrum and illustrated the PCBs in the atmospheric turbulence and marine turbulence,respectively.The basic theories and research methods of turbulence and PCBs are introduced.The measuring methods of turbulence and the space-time domain and space-frequency domain theory of PCBs are illustrated.Then,the established theory of PCCL beam with special correlation structure is analyzed.The experimental method for generating the PCCL beams has been introduced,and the importance of researching the beam has been listed.After that,based on the generalized Huygens and Fresnel’s principle,the expressions of the intensity,effective radius of curvature and beam wander of the PCCL beams in anisotropic non-Kolmogorov turbulence are derived.Numerical results indicate that,for the anisotropic non-Kolmogorov spectrum,the beam wander of the PCCL beams is decreasing with theincreasing of anisotropic parameter.And the research results indicate that the effect of anisotropic turbulence on beam wander is smaller than that of isotropic turbulence.Based on the generalized Huygens and Fresnel’s principle and the second order moments of the Wigner distribution function,the expressions of the intensity,effective radius of curvature,beam wander,Strehl ratio(SR),and the power in the bucket(PIB)of the PCCL beams in marine turbulence are derived.Comparative analyses are performed for the new models under the marine turbulence and the atmospheric turbulence.The effects of different beam parameters and turbulence parameters on the PCCL beams’ propagation properties are concluded.At last,we do a summarize for this paper,and draw a plan for the subsequent work.