Propagation Properties Of Partially Coherent Anomalous Vortex Beams In Anisotropic Non Kolmogorov Atmospheric Turbulence

As the information carrier of free space optical communication,laser is inevitably affected by atmospheric turbulence in the process of atmospheric propagation,which makes the phase wavefront of the beam change and the transmission characteristics change,which leads to a series of negative effects of beam quality degradation.It seriously restricts the application of lidar detection,surface-to-air optical communication,military and other fields.The researchers found that the vortex beam with spiral phase structure can carry more information and is a good beam carrier.Therefore,it is of practical significance to study the propagation of vortex beam in atmospheric turbulence.The beams studied in this paper are partially coherent anomalous vortex beams(PCAV-Beam),which is a special form of vortex beam.The anisotropic non kolmogorogv turbulence spectrum is used as the theoretical model of atmospheric turbulence.Based on the extended Huygens-Fresnel principle and the second moment definition of Wigner distribution function,the propagation characteristics of PCAV-Beam in anisotropic non Kolmogorov atmospheric turbulence are studied by numerical simulation.The specific research contents are as follows:1.The research purpose and significance of this paper are elaborated in detail,and the propagation of laser in atmospheric turbulence and the research situation at home and abroad are summarized and analyzed.Some common vortex beam models(Laguerre Gaussian beam,doughnut hollow beam,higher order Bessel beam,PCAV-Beam)and some common atmospheric turbulence power spectrum models are listed.The extended Huygens Fresnel principle,cross spectral density function,Wigner distribution function,second-order moment theory and other optical field statistical theories are briefly introduced.2.Based on the extended Huygens Fresnel principle,the expression of the light intensity of PCAV beam on the receiving plane is derived and numerically simulated.The influence of different topological charge number on the phase distribution of the beam and the influence of different beam order and width on the bright ring distribution are analyzed.A simultaneous interpreting expression of the intensity of PCAV-Beam in anisotropic non Kolmogorov atmospheric turbulence is derived.The relative intensity distribution of PCAV-Beams are analyzed by numerical simulation under different beam parameters:beam order、topological charge、beam width,different transmission distance and different turbulence anisotropy parameters.3.Based on the extended Huygens Fresnel principle and the second moment theory of Wigner distribution function,the M~2 factor and beam wander of PCAV-Beams propagating in anisotropic non Kolmogorov atmospheric turbulence are derived.The effects of beam parameters such as topological charge,electromagnetic initial degree of polarization and beam coherence length on M~2 factor and beam wander are studied by numerical simulation,and the effects of atmospheric turbulence parameters such as atmospheric refractive index structure constant,anisotropy parameter,generalized index parameter,internal scale of atmospheric turbulence and external scale of atmospheric turbulence on M~2 factor and beam wander are studied.