气体辐射太赫兹波产额与驱动激光强度的依赖关系  

The dependence of THz yield from gases on the intensity of driving laser field

作　　者：孙鹏燕 张磊[1] 王国利[2] SUN Peng-Yan;ZHANG Lei;WANG Guo-Li(School of Mathematics and Physics,Lanzhou Jiaotong University,Lanzhou 730070,China;College of Physics and Electronic Engineering,Northwest Normal University,Lanzhou,730070,China)

机构地区：[1]兰州交通大学数理学院,兰州730070 [2]西北师范大学物理与电子工程学院,兰州730070

出　　处：《原子与分子物理学报》2023年第3期96-101,共6页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(11864037);甘肃省自然科学基金(20JR5RA420);兰州交通大学-天津大学联合创新基金项目(2021057)。

摘　　要：利用光电流模型研究了气体辐射太赫兹波产额与驱动激光峰值强度的依赖关系.模拟表明,无论是单色激光脉冲还是双色激光场,当激光较弱时,太赫兹产额随着激光强度的增加而迅速增大;而当气体电离接近或达到饱和后,进一步增强激光场强度,太赫兹产额出现了振荡变化.与通常采用较弱激光强度相比,更高的激光强度(致使气体达到完全电离)会进一步增强太赫兹波的辐射强度.分析各个电离事件所产生电子的个数和运动轨迹的对称性,可以很好地解释这些结果.The dependence of the terahertz(THz)yield radiated from gases on the intensity of driving laser field is theoretically investigated by using photocurrent model.The simulation shows that when the laser is weak,the THz yield increases rapidly with the increase of laser intensity,regardless of monochromatic laser pulse or two-color laser field.When the gas ionization approaches or reaches saturation,the THz yield has the oscillating change with further increasing laser intensity.Higher laser intensities,which cause the gas to fully ionize,further increase the THz radiation intensity compared to the weaker intensity usually used.These results can be well explained by analyzing the number of electrons released at each ionization event and the symmetry of their trajectories.

关 键 词：光电流 太赫兹波产额 驱动激光强度 振荡 

分 类 号：O437[机械工程—光学工程]