Classification of coherent vortices creation and distance of topological charge conservation in non-Kolmogorov atmospheric turbulence

Abstract

The analytical expressions for the cross-spectral density function of partially coherent sinh-Gaussian (ShG) vortex beams propagating through free space and non-Kolmogorov atmospheric turbulence are derived, and used to study the classification of coherent vortices creation and distance of topological charge conservation. With the increment of the general structure constant and the waist width, as well as the decrement of the general exponent, the inner scale of turbulence and spatial correlation length, the distance of topological charge conservation will decrease, whereas the outer scale of turbulence and the Sh-part parameter have no effect on the distance of topological charge conservation. According to the creation, the coherent vortices are grouped into three classes: the first is the inherent coherent vortices of the vortex beams, the second is created by the vortex beams when propagating through free space, and the third is created by the atmospheric turbulence inducing the vortex beams.

Coherent Vortices Properties of Partially Coherent Elegant Laguerre-Gaussian Beams in the Free Space

“…Thus, the total angular momentum becomes zero. Particularly, we note that the position of the coherent vortex (No.1) always exists and remains stable while the position of other coherent vortices changes during propagation.We can see that is due to the fact that the coherent vortex of No.1 is inherent and created by vortex beam[23]. Other coherent vortices are produced by vortex beam propagating through free space.…”

The Propagation of Vortex Beams in Random Mediums

“…The optical field of the sinh-Gaussian vortex beam in the source plane can be specified as given in [25];…”

Propagations of Sin-Gaussian Beam with Astigmatism through Oceanic Turbulence

“…In [8,9], the application of partially coherent beam in laser communication has been analysed, revealing that prior to the coherent models, the partially coherent beams can effectively control the bit error rate of the optical communication links. Therefore, there have been considerable research activities focusing on the partially coherent beams travelling through oceanic turbulence [10][11][12][13][14][15][16][17][18]. For instance, Hermite-sinusoidal-Gaussian beams are known to be derived from the paraxial wave equation, containing massive classes of beams like sinh-(or cosh-) Gaussian and sin-(or cos-) Gaussian types [19,20] and such beams propagating through oceanic water or optical system have been extensively studied [10][11][12][13][14][15][16][17][18].…”

“…Therefore, there have been considerable research activities focusing on the partially coherent beams travelling through oceanic turbulence [10][11][12][13][14][15][16][17][18]. For instance, Hermite-sinusoidal-Gaussian beams are known to be derived from the paraxial wave equation, containing massive classes of beams like sinh-(or cosh-) Gaussian and sin-(or cos-) Gaussian types [19,20] and such beams propagating through oceanic water or optical system have been extensively studied [10][11][12][13][14][15][16][17][18]. The correlation features of Hermite-sine-Gaussian and Hermite-sinh-Gaussian beams in oceanic water have been examined [11,14].…”

“…Besides, the scintillation index of sine-Gaussian and sinh-Gaussian beams has been investigated in great detail [13]. Very recently, Li et al explore the dynamic evolution behaviour of the sine-Gaussian vortex beams and sine-Gaussian non-vortex beams travelling through free space and oceanic turbulence [17]. However, note that most of the aforesaid studies have ignored the aberration conditions.…”