Accession Number : AD0741677

Title :   A Perturbative Treatment of Thermal Blooming in Pulsed Laser Beams.

Descriptive Note : Interim rept.,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : Aitken,Alfred H.

Report Date : 18 APR 1972

Pagination or Media Count : 34

Abstract : The atmospheric propagation of pulsed, focussed, laser beams is calculated. The beam intensity is obtained by solving the equation of geometric optics and the equation of energy conservation simultaneously using a perturbative scheme. In this way the modification on propagation due to change caused by the index of refraction absorption of energy from the beam itself is included in a linear approximation. The problem of calculating the index of refraction change in a quiescent atmosphere is formulated generally with detailed expressions, valid for all times, given for the case of a paraxial Gaussian beam. Formulas for beam intensity are given as graphical results presented for the on-axis intensity of a focussed Gaussian beam. (Author)

Descriptors :   (*COHERENT RADIATION, ATMOSPHERES), PROPAGATION, LIGHT TRANSMISSION, REFRACTIVE INDEX, INTENSITY, HYDRODYNAMICS, MATHEMATICAL MODELS

Subject Categories : Atmospheric Physics
      Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE