Accession Number : AD0907395

Title :   Thermo-Optical Effects of High-Energy Laser Beams.

Descriptive Note : Technical rept. 1 Oct 70-1 Jun 72,

Corporate Author : AIR FORCE WEAPONS LAB KIRTLAND AFB NM

Personal Author(s) : Hogge, Charles B.

Report Date : DEC 1972

Pagination or Media Count : 180

Abstract : High-energy laser beams that interact with the medium through which they pass experience self-induced thermo-optical effects. In the atmosphere, radiation with a wavelength of 10.6 micrometers is absorbed mainly by CO2 and water vapor. While the generalized kinetics is complicated, the net effect of the absorption process is to change the temperature of the air in the vicinity of the beam. The subsequent index of refraction changes tend to distort the phase characteristics of the laser beam, and frequently alter the irradiance profiles substantially. This report describes work at the Air Force Weapons Laboratory on the theoretical treatment of the problem. Using the computer codes developed to do this, numerous cases typical of a high-altitude situation are studied in an attempt to parameterize the process. The calculations are designed to establish a worst case limit for the thermo-optical effects. (Author)

Descriptors :   (*GAS LASERS, PROPAGATION), ATTENUATION, ENERGY, ABSORPTION, HYDRODYNAMICS, REFRACTIVE INDEX, OPTICAL PROPERTIES, THERMAL PROPERTIES, CARBON DIOXIDE, WATER VAPOR, INTERACTIONS, VIBRATION, DATA PROCESSING, INFRARED RADIATION, AIR, DIFFERENTIAL EQUATIONS, SCATTERING, TURBULENCE, MAGNETIC FIELDS, ELECTRIC FIELDS, TRANSFORMATIONS(MATHEMATICS), COMPUTER PROGRAMMING.

Subject Categories : Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE