title: Intensity fluctuations of flat-topped beam in non-Kolmogorov weak turbulence: comment.
abstract: In J. Opt. Soc. Am. A 29, 169 (2012), Gerçekcioğlu and Baykal presented an investigation of the dependence of the scintillation index of flat-topped Gaussian beams on the exponent α of the power-law-type spectra of non-Kolmogorov turbulence. In particular, they found that the scintillation index reaches a maximum at α≈3.2. We show that this conclusion is an artifact of their specific calculation, and depends on the choice of the length unit. Gerçekcioğlu and Baykal's calculations are made for the 3<α<5 range of the spectral exponent. We show that for the homogeneous and isotropic turbulence the correct range is 3<α<4, when Markov approximation is used.
authors.affiliation: Zel Technologies, LLC, Boulder, Colorado 80305, USA. Mikhail.charnotskii@noaa.gov
authors.forename: Mikhail
authors.initials: M
authors.lastname: Charnotskii