少周期脉冲双光学选通门电场的精密调控OA

To achieve the generation of ultrashort isolated attosecond pulses using few-cycle pulses,it is ne-cessary to study the precise manipulation of the electric field of few-cycle light field through double optical gating technology.In conventional experiments,double optical gating typically regulates multi-cycle pulses,and the analysis does not consider higher-order dispersion during laser propagation in media,second-harmon-ic conversion efficiency,or the exact waveform of the second-harmonic electric field.However,such approx-imations are no longer valid for few-cycle pulses.This paper accurately simulates the propagation and second-harmonic generation process of few-cycle pulses in nonlinear crystals based on a coupled-wave equa-tion model,revealing the key influence of dispersion effects and other factors on the gating waveform.The research shows that when the driving light field is a few-cycle laser pulse,the traditional electric field estima-tion method for double optical gating is no longer applicable.Few-cycle pulse lasers have an ultra-broad spectrum,and the effects such as group velocity mismatch,phase mismatch,and dispersion caused by differ-ences in phase accumulation among different wavelength components become significantly more pro-nounced compared to long pulses.For a few-cycle pulse,the optimal gating light field can be achieved by ad-justing the thickness of the beta-barium borate(BBO)crystal in the double optical gating setup to 126.4 μm.This paper proposes that coordinated adjustment of the waveplate and BBO crystal thickness can finely tune the relative delay between the driving field and the second-harmonic field,thereby optimizing both the gat-ing and driving electric fields,providing effective parameter optimization guidance for the generation of ul-trashort isolated attosecond pulses.