Open AccessMethod for determining the characteristic parameters of the turbulence based on the measurement of M2-factor
Author(s) -
Pingping Pan,
Bin Zhang
Publication year - 2011
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.60.014215
Subject(s) - turbulence , physics , coherence (philosophical gambling strategy) , huygens–fresnel principle , optics , gaussian , scale factor (cosmology) , coherence length , gaussian beam , atmospheric turbulence , computational physics , beam (structure) , statistical physics , mechanics , quantum mechanics , superconductivity , cosmology , metric expansion of space , dark energy
Based on the extended Huygens-Fresnel principle and theory for the turbulence, the analytical expression for the beam propagation factor (M2-factor) of partially coherent beams propagating in a turbulent atmosphere has been derived. The effects of the structure constant of the refractive index fluctuations C2n and the inner scale of the turbulence l0on the M 2 factor have been analyzed quantitatively. Consequently, a new method for determining the characteristic parameters of the turbulence based on the measurement of the M 2 factor by experiments has been proposed. The results show that the laser beams with better spatial coherence property are more sensitive to the effects of turbulence, so the fundamental Gaussian beams with fully coherence can be used as the source in the measurement, and the usual instruments for measuring the M 2-factor can be adopted as the experiment equipments. It is very simple and convenient to determine the characteristic parameters of the turbulence by applying the method proposed in this paper.