摘要
给出了两种特殊风向对小尺度热晕不稳定性扰动能量增长影响的实验及数值计算结果：当风向与扰动梯度方向平行时，风速对不稳定性有明显的抑制作用，而垂直于机动梯度方向的风则对热晕不稳定性没有影响。
AbstractThe small scale thermal blooming instability,which limits the maximum power of laserbeam propagation in the atmosphere,has been the subject of much of the research.Theinstability can be excited not only by the noise on the laser beam,but also by opticalturbulence along the atmospheric path.The linear theory and the numerical simulation haveshown that the instability can be partly damped by the atmospheric random wind,To getmuch more physical insight into the problem,the directional intensity perturbations areseeded in the high power laser beam in our experiment.Effects of the wind direction andgradient on the small scale thermal blooming instability of the laser beam are studied.Theexperimental results are also compared with that of the numerical simulation in this paper.The results show that the wind,parallel to the direction of perturbation gradient can partlysuppress the instability.The greater the wind gradientis,the more the instability issuppressed. However the wind,vertical to the direction of perturbation gradient, does notsuppress the instability.Effects of wind direction and gradient on the small scale thermalblooming instability of high power laser beam propagation in the real atmosphere are muchmore complicate due to the turbulence,the detail numerical simulation must be required toobtain quantitative results.
出处
《强激光与粒子束》
EI
CAS
CSCD
1995年第3期449-452,共4页
High Power Laser and Particle Beams
关键词
小尺度
热晕
风向
风速
激光传输
Atmospheric optics
Stability
Thermal blooming
Transport properties
Wind
