Transient surface electromagnetic fields triggered by a super-short laser pulse through ultrafast generation of a charge-separation field at a high-conductivity target have been studied. Both the analytic theory applicable to the near-field problem and the finite-difference time-domain simulations clearly manifest distinctive features of the proposed mechanism, which is associated with fast electric polarization of a high-conductivity target by rapidly switching on a charge-separation field when an ultrashort laser pulse quickly pushes the target electrons out to a vacuum. This mechanism is well suited for the current trend in creating lasers with a record short pulse duration for laser–plasma interactions.
超短激光脉冲通过在高电导率靶材上快速产生电荷分离场，从而触发瞬态表面电磁场的研究已得以开展。适用于近场问题的解析理论以及时域有限差分模拟均清晰地展示了所提出机制的独特特征，该机制与高电导率靶材在电荷分离场快速开启时的快速电极化相关，而这一过程源于超短激光脉冲将靶材电子迅速推向真空。该机制与当前追求创纪录短脉冲持续时间激光器的趋势高度契合，适用于激光–等离子体相互作用领域。