Characteristics of high-power partially coherent laser beams propagating upwards in the turbulent atmosphere
Yu Deng, Huan Wang, Xiaoling Ji, Xiaoqing Li, Hong Yu, Lifeng Chen
Abstract
The characteristics of high-power partially coherent laser beams propagating upwards in the turbulent atmosphere are studied, where the principal features of diffraction, nonlinear self-focusing and turbulence are considered. Based on the "thin window" model, the analytical propagation formulae are derived by using the quadratic approximation of the nonlinear phase shift. It is found that the turbulence effect plays an important role in beam propagation characteristics. But the turbulence and self-focusing effects can be suppressed by increasing the laser elevation. Furthermore, the influence of laser elevation on the turbulence effect is stronger than that on the self-focusing effect, and influence of laser elevation on the self-focusing effect is stronger than that on the diffraction effect. In particular, the optimal focal length and wavelength are proposed to decrease the beam spot size on the target.