<title>Computer Techniques For The Solution Of The High Energy Laser Propagation Problem</title>

Abstract

High energy laser propagation in an absorbing medium is described by the Fresnel equation with a nonlinear term.While perturbative solutions exist for some special simple cases, the most useful approach has required development of efficient computer algorithms to satisfactorily solve problems of interest. This paper reviews the numerical techniques which iteratively solve nonlinear laser propagation problems and indicates the agreement obtained in comparison with laboratory experiments. The wide range of physical effects in addition to the nonlinear phenomena which are also included in the computer codes to predict the propagation of the laser beam from the laser cavity, through the optical train and into the atmosphere are also discussed. AbstractHigh energy laser propagation in an absorbing medium is described by the Fresnel equation with a nonlinear term. While perturbative solutions exist for some special simple cases, the most useful approach has required development of efficient computer algorithms to satisfactorily solve problems of interest. This paper reviews the numerical techniques which iteratively solve nonlinear laser propagation problems and indicates the agreement obtained in comparison with laboratory experiments. The wide range of physical effects in addition to the nonlinear phenomena which are also included in the computer codes to predict the propagation of the laser beam from the laser cavity, through the optical train and into the atmosphere are also discussed.

<title>Overview Of Atmospheric Effects On The Propagation Of High Energy Laser Radiation</title>

“…It is interesting to note that, based simply on these values for q, the annular uniform beam shape gives about the same I as the uniform beam but for less than half the power. In Figure 4 the power optimization curves based simply on the Table 2 4 (16) Transient /single -pulse blooming. For pulsed beams transient blooming effects become important.…”

“…Cordray and Ulrich review in their paper some of the numerical techniques used to investigate these effects. 16 In the paper by Breaux, a simplified scaling law approach is described for predicting steady-state thermal blooming effects for both cw and multiple pulse beams. 9…”