Kroon D, Guénot D, Kotur M, Balogh E, Larsen E W, Heyl C M, Miranda M, Gisselbrecht M, Mauritsson J, Johnsson P, Varjú K, L'huillier A, Arnold C L
Opt Lett. 2014 Apr 1;39(7):2218-21. doi: 10.1364/OL.39.002218.
We study the influence of the generation conditions on the group delay of attosecond pulses in high-order harmonic generation in gases. The group delay relative to the fundamental field is found to decrease with increasing gas pressure in the generation cell, reflecting a temporal walk-off due to the dispersive properties of the nonlinear medium. This effect is well reproduced using an on-axis phase-matching model of high-order harmonic generation in an absorbing gas.
我们研究了产生条件对气体中高次谐波产生时阿秒脉冲群延迟的影响。相对于基频场的群延迟被发现随着产生池中气体压力的增加而减小，这反映了由于非线性介质的色散特性导致的时间走离。使用吸收气体中高次谐波产生的轴上相位匹配模型，很好地再现了这种效应。
