Investigação teórica dos fenômenos da propagação atmosférica de feixes lasers de alta potência.

Abstract

This work aims at the development of an analytical formulation and computational modeling of the beam propagation of continuous high-energy lasers (HEL) through the atmosphere. The main phenomena that degrade propagation, thermal blooming and scintillation are studied. For this purpose, a coupled numerical solution was implemented using the Navier- Stokes equations for mass, momentum and energy conservation, the paraxial equation and a phase screen model to represent the optical turbulence. The thermal blooming effect is modeled through the coupling between the Navier-Stokes system of equations and the paraxial equation. Optical turbulence is simulated using a phase screen scheme that incorporates stochastic temperature fluctuation changes, following a spectral distribution based on Kolmogorov’s theory for the range of isotropic turbulence. Numerical results are presented varying parameters such as: laser power, turbulence level and laser diameter. These variations are performed by altering the dimensionless numbers that constitute the fluid dynamics equations.