Cai Xunming, Zhao Jingyun, Lin Qiang, Tong Hong, Liu Jiangtao
Opt Express. 2018 Nov 12;26(23):30030-30041. doi: 10.1364/OE.26.030030.
The space-time properties of the expressions of sub-cycle and single-cycle focused optical pulses with radially polarized electromagnetic field based on the Sink-Source model are studied. The self-induced blue shift of the center frequency of spectrum in the center of the pulse field is found to have an important impact on the electrons acceleration. When the electrons approach to the center of pulse, the electrons will obtain a large kinetic energy gain in a short time. The effect of radiation-reaction force can't be ignored if the net kinetic energy gain of electrons is more than GeVs. The electrons will deviate from the original acceleration channel and the gain of kinetic energy that electrons may gain will be greatly reduced if the radiation-reaction effect is considered. In contrast to the few-cycle laser pulse accelerating electrons, the gain of kinetic energy obtained by electrons is a few times higher and the corresponding peak optical power is one order of magnitude lower in the case of the sub-cycle laser pulses accelerating electrons. The maximal kinetic energy gain of electrons is robust against the variation of the incident angles.
基于Sink-Source模型研究了具有径向极化电磁场的亚周期和单周期聚焦光脉冲表达式的时空特性。发现脉冲场中心频谱中心频率的自诱导蓝移对电子加速有重要影响。当电子靠近脉冲中心时，电子将在短时间内获得大量动能增益。如果电子的净动能增益超过GeV，辐射反作用力的影响就不能忽略。如果考虑辐射反作用效应，电子将偏离原来的加速通道，电子可能获得的动能增益将大大降低。与少周期激光脉冲加速电子相比，亚周期激光脉冲加速电子时，电子获得的动能增益高出几倍，相应的峰值光功率低一个数量级。电子的最大动能增益对入射角的变化具有鲁棒性。
