高功率激光放大器中光束的成丝和B积分  

Filamentation of Intense Laser Beam in High Power Laser and the B Integral

作　　者：文双春 范滇元[2] 

机构地区：[1]高功率激光物理国家重点实验室,上海201800 [2]中国科学院上海光学精密机械研究所,上海201800

出　　处：《光学学报》2001年第11期1331-1335,共5页Acta Optica Sinica

基　　金：国家高技术研究发展计划 (86 3 416 5 )

摘　　要：研究了高功率激光放大器中光束的成丝问题。利用弗兰兹 诺德威克 (Frantz Nodvik)模型将准稳态波动方程推广到介质有饱和增益的情形 ,进而得到高功率激光放大器中小尺度调制的传输方程。在小信号增益和饱和增益情形下 ,分别得到了小尺度调制方程的精确解析解和数值解。结果表明 ,对于相同的输入光强 ,增益使小尺度调制增益谱的范围加宽 ,最快增长频率增高 ,最大增长率提高 ;同时 ,在放大介质中 ,小尺度调制的最快增长频率和最大增长率还随传输距离变化。The problem of filamentation of optical beam in high power laser is studied by taking into account the effect of saturating gain. A set of propagation equations for small-scale modulation is derived. An exact analytic solution to the derived equation is obtained in the case of small signal gain. In the case of saturating gain, the obtained equation is solved numerically. It is found that for a given input power, the cutoff spatial frequency, the fastest growing frequency and the maximum growth rate increase in an amplifying medium, and vary with propagation distance. The saturating effect of gain lowers the growth rate of the B integral and the small-scale modulation propagating in the amplifying medium.

关 键 词：小尺度自聚焦 成丝 B积分 高功率激光放大器 光束 ICF装置 惯性约束聚变装置 

分 类 号：TN722.32[电子电信—电路与系统] TL639[核科学技术—核技术及应用]