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