【摘要】 给出了低密度等离子体中包含高阶相对论效应的激光场传输方程 .用变分法研究了强激光束在等离子体通道中传输时包括真空衍射、等离子体通道和低阶与高阶相对论效应对传输的影响 .在傍轴近似下 ,激光束宽依然有“势阱”方程 .当激光强度较大时 ,高阶相对论效应变得重要 :它一方面减小激光束宽的振荡幅度 ,另一方面又加快激光束宽的振荡速度 .当激光功率大于 (等于 )相对论临界功率时 ,高阶相对论效应避免了激光强度随传输距离出现无穷大的奇异性 .同时 ,给出了考虑高阶相对论效应后激光束宽平衡解的存在条件 .更多还原

【Abstract】 In an underdense plasma, the laser wave equation is given with higher-order-relativistic (HOR) effect. A variational methed is used to study HOR effect for intense laser beam propagation in plasma channel including diffraction, pre-formed plasma channel guiding and lower order relativistic effects. In the paraxial approximation, a potential well also exists for laser spot size. HOR effect decreases the amplitude of laser spot size oscillation, whereas accelerates its rate. Furthermore, it prevents the singularity of infinite intesity of laser beam when laser power is greater than (or equal to) the relativistic critical power. The condition of balance-solution of the beam spot size is also given.更多还原