Open AccessBeam propagation factor of cosh-Gaussian array beams propagating through atmospheric turbulence
Author(s) -
Liu Fei,
Xiaoling Ji
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.60.014216
Subject(s) - physics , turbulence , beam (structure) , optics , m squared , gaussian , gaussian beam , atmospheric turbulence , beam diameter , computational physics , mechanics , quantum mechanics , laser beams , laser
The analytical formula for the beam propagation factor ( M 2-factor) of cosh-Gaussian (ChG) array beams propagating through atmospheric turbulence is derived, and the influence of turbulence on the M 2-factor is studied by using the relative M 2-factor. It is shown that the M 2-factor is not a propagation invariant in turbulence, and the turbulence results in an increase of the M 2-factor. For the incoherent combination, the M 2-factor of ChG array beams increases with increasing propagation distance, beam parameter, relative beam separation distance and beam number. For the coherent combination, the M 2-factor of ChG array beams increases with oscillatory behavior as the beam parameter or the relative beam separation distance increases. For the coherent combination the M 2-factor is always smaller than that for the incoherent combination. However, for the incoherent combination the M 2-factor is always less sensitive to turbulence than that for the coherent combination. In particular, the influence of turbulence on the M 2-factor can be reduced by a suitable choice of the relative beam separation distance. With increasing beam number, the M 2-factor becomes more sensitive to turbulence for the coherent combination, while for the incoherent combination the M 2-factor becomes less sensitive to turbulence.