HIGH INTENSITY LASER PROPAGATION IN THE ATMOSPHERE
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 28, 1967
- Accession Number
- AD0816417
Entities
People
- Donald Arnush
- Lee M. Frantz
- Theodore D. Holstein