Shooting attosecond movie

We studied the autoionziation of argon atom, which is a process governed by electron-electron correlation. The Fano profile, which is the signature of the autoionization process, has widespread significance in many scientific disciplines. For decades, spectral-domain measurements with synchrotron radiation have served as a window into the rich dynamics of autoionization. However, the synchrotron pulse duration is too long (ps) to time-resolve the Fano resonances since the autoionization lifetimes can be as short as a few femtoseconds. We measured the transmitted XUV signal at the energy of the unperturbed 3s3p64p (26.6 eV) and 3s3p65p (28.0 eV) peaks as a function of the delay. At the NIR laser peak intensity of ~1012 W/cm, the 3s3p65p and 3s3p66p states primarily exhibit an energy shift as well as broadening and weakening of the resonances. The observed phenomena suggest a dynamic control over the autoionizing states by the NIR laser.

He Wang, Michael Chini, Shouyuan Chen, Chang-Hua Zhang, Feng He, Yan Cheng, Yi Wu, Uwe Thumm, and Zenghu Chang, “Attosecond Time-Resolved Autoionization of Argon,” Phys. Rev. Lett. 105, 143002 (2010).

Steve Gilbertson, Sabih D. Khan, Yi Wu, Michael Chini, Zenghu Chang,“Isolated attosecond pulse generation without the need to stabilize the carrier-envelope phase of driving lasers,” Phys. Rev. Lett. 105, 093902 (2010).