Accession Number:

AD0816417

Title:

HIGH INTENSITY LASER PROPAGATION IN THE ATMOSPHERE

Descriptive Note:

Final rept. 1 Nov 1965-28 Feb 1967

Corporate Author:

TRW SYSTEMS REDONDO BEACH CA QUANTUM PHYSICS LAB

Personal Author(s):

Report Date:

1967-02-28

Pagination or Media Count:

117.0

Abstract:

The phenomena which constitute ultimate limitations to the transmission of intense laser radiation through the atmosphere are investigated, namely, self-defocusing due to atmospheric heating and the stimulated Raman effect. The heating studies are concerned with processes contributing to residual absorption in atmospheric transmission windows. A quantum mechanical study of the far-wing pressure broadening of molecular vibrational lines is carried out. The spectral distance beyond which the Lorentz-type behavior fails is found as a function of temperature and range of the interaction potential. It is shown that far wing fall-off is exponential. An analysis is made of collision induced absorption with emphasis on the far-wing behavior. A calculation is performed specifically for absorption during collisions between rare gas atoms a numerical computation phase remains. Laser beam depletion by stimulated Raman scattering is investigated using a rate equation description. The particular effects are the interaction of competing Raman backscattered light, and the effect of pressure dependence on the propagation of a beam vertically through the atmosphere. The maximum intensity which can be transmitted through the atmosphere without frequency change due to Raman scattering is calculated.

Descriptors:

Subject Categories:

  • Atmospheric Physics
  • Lasers and Masers
  • Nuclear Physics and Elementary Particle Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE


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