Elektronik ve Haberleşme Mühendisliği Bölümü Yayın Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/260
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Article Citation - WoS: 8Citation - Scopus: 9Scintillation Properties of a Truncated Flat-Topped Beam in a Weakly Turbulent Atmosphere(Elsevier Sci Ltd, 2013) Liu, Xianlong; Liang, Chunhao; Yuan, Yangsheng; Cai, Yangjian; Eyyuboglu, Halil T.We derive derive an explicit expression for the scintillation index of a truncated flat-topped (FT) beam in a weakly turbulent atmosphere. Under suitable conditions, the derived formula reduces to the expression for the scintillation index of a FT beam or Gaussian beam without truncation. The scintillation properties of a truncated FT beam in a weakly turbulent atmosphere are illustrated numerically. It is found that the truncation parameter has strong influence on the scintillation properties, and the advantage of a FT beam over a Gaussian beam for reducing the negative influence of turbulence disappears gradually as the truncation parameter decreases. (C) 2012 Elsevier Ltd. All rights reserved.Article Citation - WoS: 26Citation - Scopus: 33Propagation Factors of Hermite-Gaussian Beams in Turbulent Atmosphere(Elsevier Sci Ltd, 2010) Yuan, Yangsheng; Cai, Yangjian; Qu, Jun; Eyyuboglu, Halil T.; Baykal, YahyaBased on the extended Huygens-Fresnel integral and the second-order moments of the Wigner distribution function, an analytical formulae for the propagation factors (M-2-factors) of coherent and partially coherent one-dimensional Hermite-Gaussian beams in a turbulent atmosphere are derived. Evolution properties of the M-2-factor of the Hermite-Gaussian beam in a turbulent atmosphere are studied numerically in detail. Our results show that the M-2-factor of the Hermite-Gaussian beam increases upon propagation in a turbulent atmosphere. The M-2-factor of the Hermite-Gaussian beam with larger beam order (or lower coherence) increases slower that of the Hermite-Gaussian beam with smaller beam order (or higher coherence) in a turbulent atmosphere, which means that the Hermite-Gaussian beam with a larger beam order and lower coherence is less affected by a turbulent atmosphere. Our results will be useful in long-distance free-space optical communications. (c) 2010 Elsevier Ltd. All rights reserved.