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laser beam propagation in atmospheric turbulenceThe optical effects of atmospheric turbulence on the propagation of low power laser beams are reviewed in this paper. The optical effects are produced by the temperature fluctuations which result in fluctuations of the refractive index of air. The commonly-used models of index-of-refraction fluctuations are presented. Laser beams experience fluctuations of beam size, beam position, and intensity distribution within the beam due to refractive turbulence. Some of the observed effects are qualitatively explained by treating the turbulent atmosphere as a collection of moving gaseous lenses of various sizes. Analytical results and experimental verifications of the variance, covariance and probability distribution of intensity fluctuations in weak turbulence are presented. For stronger turbulence, a saturation of the optical scintillations is observed. The saturation of scintillations involves a progressive break-up of the beam into multiple patches; the beam loses some of its lateral coherence. Heterodyne systems operating in a turbulent atmosphere experience a loss of heterodyne signal due to the destruction of coherence.
Document ID
19800037762
Document Type
Reprint (Version printed in journal)
Authors
Murty, S. S. R.
(Alabama A & M University Normal, Ala., United States)
Date Acquired
August 10, 2013
Publication Date
May 1, 1979
Subject Category
LASERS AND MASERS
Funding Number(s)
CONTRACT_GRANT: NSG-8037
Distribution Limits
Public
Copyright
Other