Accession Number : AD0708896

Title :   LASER BEAM TRANSMISSION THROUGH THE ATMOSPHERE.

Descriptive Note : Research rept.,

Corporate Author : AVCO EVERETT RESEARCH LAB EVERETT MASS

Personal Author(s) : Wallace,J. , Jr. ; Camac,M.

Report Date : MAR 1970

Pagination or Media Count : 46

Abstract : Theoretical evaluation of the transmission of a laser beam at 10.6 microns has been investigated using the techniques of geometric optics. The interaction is non-linear because the refractive index depends through the mechanism of absorption, upon the intensity of the propagating wave. Atmospheric absorption at 10.6 microns is caused by CO2 and H2O in the atmosphere. Associated with absorption by CO2 and transverse flow caused by atmospheric winds or beam motion are vibrational relaxation effects which can either heat or cool the atmosphere. If the atmosphere is cooled, the beam is self-focused. The velocity-altitude dependence of heating and cooling regimes are defined and detailed intensity distributions in each regime are presented. (Author)

Descriptors :   (*LASERS, IONOSPHERIC PROPAGATION), COHERENT RADIATION, ELECTROMAGNETIC RADIATION, REFRACTIVE INDEX, ABSORPTION, CARBON DIOXIDE, ATMOSPHERIC REFRACTION

Subject Categories : Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE