多脉冲激光增强太赫兹辐射的PIC模拟

 模拟了强激光和稀薄非均匀等离子体相互作用在界面辐射超强太赫兹波的物理过程，提出了利用多脉冲激光增强太赫兹辐射的方案，详细研究了多脉冲激光的脉冲个数（取１～４个）、脉冲间距等因素对太赫兹辐射功率和频率的影响。当入射激光包含4个脉冲时，辐射最强，此时的辐射功率是相同条件下单脉冲的6倍，可达到7.16 MW，辐射的太赫兹波的脉宽约为330 fs,总能量约为1 μJ。研究结果表明:多脉冲激光可以显著增强太赫兹辐射，且随着脉冲个数的增加，激起的电子静电波振幅变大，辐射功率也随之变大，直到尾流场饱和；当脉冲间距等于入射激光脉宽时辐射最强。

PIC simulation on Terahertz radiation enhanced by multiple laser pulses

Numerical simulations are conducted on the THz radiation excited from the laser plasma interaction with the help of 2D3V PIC code. A new scheme using multiple laser pulses to enhance the THz radiation is proposed, and the effects of pulse number(1~4) and interval on the radiation power and frequency are investigated. With an incident laser with four pulses irradiaton, THz radiation with power of 7.16 MW is obtained. which is 6 times of that with a single pulse laser irradiation. The pulse width of THz radiation is about 330 fs, and the total enrgy is 1 μＪ．The results show that an incident laser with multiple pulses can enhance the radiation obviously, and with the laser pulse number increasing, the amplitude of the electrostatic wave increases synchronously, which makes the THz radiati