Effects of Anisotropic Turbulence on Propagation Characteristics of Partially Coherent Beams with Spatially Varying Coherence

Abstract

Based on the extended Huygens-Fresnel (eHF) principle, approximate analytical expressions for the spectral density of nonuniformly correlated (NUC) beams are derived with the help of discrete model decompositions. The beams are propagating along horizontal paths through an anisotropic turbulent medium. Based on the derived formula, the influence of the anisotropic turbulence (anisotropy factors, structure parameters) on the evolution of the average intensity, the shift of the intensity maxima and the power-in-the-bucket (PIB) are investigated in detail through numerical examples. It is found that the lateral shifting of the intensity maxima is closely related to the anisotropy factors and the strength of turbulence. Our results also reveal that, in the case of weak turbulence, the beam profile can retain the feature of local intensity sharpness, but this feature degenerates quickly if the strength of the turbulence increases. The value of PIB of the NUC beams can be even higher than that of Gaussian beams by appropriately controlling the coherence parameter in the weak turbulence regime. This feature makes the NUC beams useful for free-space communication.

Performance of Orbital Angular Momentum Communication for a Non-Uniformly Correlated High-Order Bessel–Gaussian Beam in a Turbulent Atmosphere

“…The research results show that the scintillation of Gaussian non-uniformly correlated beams and Hermite non-uniformly correlated beams was lower than that of the Gaussian-Schell model beams [37,38]. The power-in-the-bucket value can be enhanced under conditions of weakly anisotropic turbulence by controlling the coherence parameter for non-uniformly correlated beams [39]. In one study, convex partially coherent flat-topped beams were used to improve the mean SNR and reduce the mean BER [40].…”

“…Two high-index particles were trapped simultaneously and manipulated in the longitudinal direction via focused structured optical fields with a spatially nonuniform correlation [36]. Non-uniformly correlated beams can also be used to resist the negative effects induced by atmospheric turbulence [37][38][39][40][41][42]. The research results show that the scintillation of Gaussian non-uniformly correlated beams and Hermite non-uniformly correlated beams was lower than that of the Gaussian-Schell model beams [37,38].…”

Wave Structure Function and Long-Exposure MTF for Gaussian-Beam Waves Propagating in Anisotropic Maritime Atmospheric Turbulence

“…Toselli is one of them and he analyzes the angle of arrival fluctuations by using the generalized exponent factor α instead of the standard exponent value 11/3 [5] and the anisotropic factor is also used to describe the anisotropy of the atmosphere turbulence [6]. In addition, there are also numerous studies on beam wanders, loss of spatial coherence, and the angle of arrival fluctuation [10][11][12][13][14], which are all related to the random fluctuation of optical waves propagating through terrestrial turbulence.…”

Generation of an Adjustable Optical Cage through Focusing an Apertured Bessel-Gaussian Correlated Schell-Model Beam

“…Recently, partially coherent beams with nonconventional correlation functions (NCFs) have been widely investigated [21,22]. Several types of partially coherent sources with NCFs have been introduced and generated through various coherence manipulation methods [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. These novel sources exhibit many interesting propagation properties, and are expected to be useful in many…”