Scintillations of cos-Gaussian and annular beams

Abstract

Based on the generalized beam formulation, we derive the scintillation index and selectively evaluate it for cos-Gaussian and annular beams propagating in weak atmospheric turbulence. Dependence of the scintillation index on propagation length, focusing and displacement parameters, wavelength of operation, and source size are individually investigated. From our graphical outputs, it is observed that a cos-Gaussian beam exhibits lower scintillations and thus has a tendency to be advantageous over a pure Gaussian beam particularly at lower propagation lengths. It is also found that at longer propagation lengths, this advantage switches to the side of the annular beam. Furthermore, the scintillation index of a focused annular beam will be below those of both Gaussian and cos-Gaussian beams starting at earlier propagation distances. When analyzed against source sizes, it is seen that cos-Gaussian beams will offer advantages at relatively large source sizes, while the reverse will be applicable for annular beams.

Effect of the atmospheric turbulence on a special correlated radially polarized beam on propagation

“…When δ g0 tends to infinity, Eq. (22) reduces to the BCP matrix of the completely coherent RP beam. In the paraxial region, the propagation of the elements of BCP matrix of the PCRP beam in atmospheric turbulence can also be treated by the extended Huygens-Fresnel integral formula shown in Eq.…”

“…In general, the atmospheric turbulence will cause the extra spreading beyond the diffraction, wander and scintillation of laser beams, which limits the performance in the previously mentioned applications. Thus, knowledge of the propagation behavior of light beams in atmospheric turbulence is utmost significant [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34]. It is known that decreasing spatial coherence and modulating polarization distribution of light beams are two effective methods to reduce the turbulence-induced degradation.…”

Nonparaxial propagation of a rectangular multi-Gaussian Schell-model beam

“…Since Gaussian Schell-Model (GSM) beam was firstly introduced by Wolf and Collett [1], researches about partially coherent beams have been intensively examined [2][3][4][5][6][7][8][9]. Recently, a novel named Rectangular Multi-Gaussian Schell-Model (RMGSM) was introduced by Korotkova [10], which is different from other Schell-Model class of partially coherent beams by virtue of its flat rectangular intensity distribution in the far field [11][12][13][14].…”

Effective Rayleigh range of Gaussian array beams propagating through atmospheric turbulence

“…[10]. Recently, much work has been carried out concerning the influence of turbulence on the intensity distribution, the beam width, the angular spread, the polarization, the coherence and the spectrum of different single laser beams and laser array beams [11][12][13][14][15][16][17][18][19][20][21][22][23]. As yet, only few papers have dealt with the Rayleigh range of laser beams propagating through atmospheric turbulence.…”