Atmospheric Effects On Laser Propagation

The linearized theory of thermal blooming instabilities is reviewed. The dispersion relation is derived for unstable modes with and without correction. Perfect phase-only correction is unstable at all spatial scales, while perfect field conjugation is stable at all scales. Various atmospheric phenomena such as turbulence, diffusion and wind shear may mitigate or dampen the instabilities. Full nonlinear time-dependent computer simulations of laser atmospheric propagation agree with the dispersion relation for small perturbations, and show saturation and nonlinear mode beating at long times.