Author:
Hu 胡 Jie 杰,Wang 王 Yi-Chen 一琛,Jing 景 Qiu-Shuang 秋霜,Jiang 姜 Wei 威,Wang 王 Ge-Wen 革文,Zhao 赵 Yi-Wen 逸文,Xiao 肖 Bo 礴,Liang 梁 Hong-Jing 红静,Ma 马 Ri 日
Abstract
High-order harmonic generation (HHG) of Ar atom in an elliptically polarized intense laser field is experimentally investigated in this work. Interestingly, the anomalous ellipticity dependence on the laser ellipticity (ε) in the lower-order harmonics is observed, specifically in the 13rd-order, which displays a maximal harmonic intensity at ε ≈ 0.1, rather than at ε = 0 as expected. This contradicts the general trend of harmonic yield, which typically decreases with the increase of laser ellipticity. In this study, we attribute this phenomenon to the disruption of the symmetry of the wave function by the Coulomb effect, leading to the generation of a harmonic with high ellipticity. This finding provides valuable insights into the behavior of elliptically polarized harmonics and opens up a potential way for exploring new applications in ultrafast spectroscopy and light–matter interactions.