Polarization characteristics of partially coherent radially and azimuthally polarized beams with vortex phase propagating through atmospheric turbulence

Abstract

Analytical formulas for the normalized spectral Stokes parameters of the partially coherent radially and azimuthally polarized beams with vortex phase (i.e., PCRPV and PCAPV beams) propagating through the turbulent atmosphere are derived. The polarization properties of PCRPV and PCAPV beams in atmospheric turbulence have been studied in detail. Our findings show that different correlation lengths induce nonuniform distribution to degree of polarization (DOP) and the normalized spectral Stokes parameters. And different correlation lengths also cause the polarization singularity splitting. Besides, we find also that the vortex phase will lead to the rotation of distributions of orientation angles and the normalized spectral Stokes parameters of PCRPV and PCAPV beams in turbulence, and the rotation degree will become obvious with increasing topological charge number. It can be found also that larger topological charge number can reduce the speed of polarization singularities destroyed by atmospheric turbulence, meaning that PCRPV and PCAPV beams with a larger topological charge has a stronger ability to resist atmospheric turbulence. Our studies could be important for free-space optical communications and polarization lidar system.

Evolution properties of partially coherent electromagnetic elliptical vortex beam propagating through atmospheric turbulence

“…However, because PC beam is not described by electric field but by CSD, we need to set a complex screen (CS) at the source plane to synthesize PC beam source [7,44]. Consequently, firstly, the electric field of a fully coherent beam which modulated by a CS can be given as [7,41,44]:…”

“…The reason for this phenomenon is that the disturbance of atmospheric turbulence is very complex; and the multi-phase screen method is generated the image by random numbers. Therefore, it is normal for this phenomenon [7,41].…”

“…<  represents ellipticity in the paper ; n denotes the topological charge. Meanwhile, to study the statistical properties of PCEEVB, the expression of 2 × 2 cross spectral density matrix (CSDM) is given as follows [21,34,[41][42][43][44]:…”

“…Therefore, we can get the elements of CSDM of PCEEVB in the incident plane read [21,34,[41][42][43][44]:…”

“…Therefore, we briefly outline the principle of multi-phase screen method here. The schematic diagram of it is shown in figure 7 [7,41,44].…”