基于飞秒激光光丝阵列,从实验上实现了太赫兹(THz)辐射的增强。结果表明,使用阶跃型相位板产生光丝阵列,在相同飞秒脉冲能量下,相比于单光丝情况,光丝阵列辐射THz信号强度被增强,且THz信号强度与光丝数目成正比。当入射能量为5.8 mJ时,8根光丝时辐射的THz能量为31.73 nJ,辐射效率为5.47×10 ^-6。所提方法有望解决飞秒激光辐射THz过程中的能量饱和问题。

In this study, we experimentally demonstrated the enhancement of a terahertz (THz) signal generated by a femtosecond laser-filament array in air using a simple experimental setup in which a step phase plate is used to generate multiple parallel filaments. The results show that at a given incident-femtosecond-pulse energy, compared with the case of single filament, the proposed method enhances the THz radiation intensity, and the THz radiation intensity is proportional to the number of filaments. Further, at an incident energy of 5.8 mJ, the THz energy generated by eight filaments is 31.73 nJ and the radiation efficiency is 5.47×10 -6. This simple method can be used to solve the energy saturation problem in the generation of THz radiation through femtosecond laser filamentation in air.