Study On Beam Wander Under Strong Fluctuation Condition

When the beam propagates in the turbulent medium,it will be affected by the random disturbance of temperature and other factors,which leads to the fluctuation of the refractive index.In this way,the beam will no longer maintain the original path,but the center of mass of the beam will shift.For the phenomenon of beam wander,the theoretical study of beam wander under weak fluctuation condition has a good applicability,but the theoretical study of beam wander under strong fluctuation condition is very little,so it is still necessary to futher study the beam wander theory under strong fluctuation condition.Based on the Andrews beam wander model,this paper mainly studies the beam wander under strong fluctuation condition.In order to study the influence of outer scale and inner scale of atmospheric turbulence on the beam wander characteristics,in the case of strong fluctuation condition,using the modified von Karman spectrum,the beam wander variance expressions of Gaussian beams propagating in focusing and collimating conditions are derived respectively,and verified by the experimental data.Using numerical simulation,the influence of different turbulence conditions on the beam wander characteristics is simulated,including the turbulence fluctuation,outer scale and inner scale.The simulation results are compared with the theoretical results.The results show that the turbulence fluctuation and the size of the outer scale have great influence on the beam wander.When the turbulence fluctuation becomes stronger or the outer scale becomes larger,the beam wander will be more serious.The change of the inner scale has no significant effect on the characteristics of the beam wander,which can be ignored in the study,It provides a theoretical basis and reference for the experimental application of beam wander.