论文部分内容阅读
本文通过理论和数值模拟,研究少周期激光脉冲电离气体原子产生的离化电流以及相应的THz波辐射.研究表明,少周期激光脉冲离化气体后能产生较大的离化电流,因而可以产生较强的THz辐射.不同的少周期激光脉冲相位导致电离出的电子初始速度和电离起始时刻不同,从而产生的离化电流有所不同,辐射的THz波随激光脉冲的相位成周期性变化.该理论得到一维PIC数值模拟的验证.对于给定的激光脉冲相位,离化电流和THz辐射振幅并没有随入射激光振幅的增加而单调增加,而是存在一些极值点.与均匀分布气体相比,当气体分布具有一定梯度时,辐射表现相似的规律,但频谱会发生一定的变化.
In this paper, the ionization current and the corresponding THz wave radiation generated by the low-period laser pulsed ionization gas atoms are studied by theoretical and numerical simulation.The results show that the small ionization gas can generate a large ionization current after the pulsed laser pulse, Strong THz radiation.Different periodic laser pulses lead to different initial ionization rates and ionization initiation times, resulting in different ionization currents.The radiation THz waves periodically change with the phase of the laser pulse .This theory is verified by one-dimensional PIC numerical simulation.For a given laser pulse phase, the ionization current and THz radiation amplitude do not monotonically increase with the increase of incident laser amplitude, but there are some extremum points.With the uniform distribution Compared with gas, when the gas distribution has a certain gradient, the radiation behaves in a similar way, but the spectrum will change a certain amount.