Coherent control of photon-dressed fringes by attosecond transient absorption
Qianyu Qiu, Guangru Bai, Qian Zhang +1 more
Line shapes observed in attosecond transient absorption spectra (ATAS) encode information on the phase of the optical dipole response. Understanding and controlling the phase evolution of interference fringes is among the fundamental goals of exploring coherent interaction. Here, we simulate the attosecond transient absorption in the near-infrared (NIR) dressing field by considering a three-level model in the adiabatic approximation. We find that the absorption line shape can be changed from Lorentzian to Fano to inverted Lorentzian and back again at two-photon dressed energy levels “ω ± 2ωι”, and line shapes evolve in half-cycle periodicity (T/2). Moreover, the direction of phase evolution of “ω ± 2ωι” is opposite, while the phases of “ω ± 2ωι” are roughly the same at certain delays with an interval of approximately a quarter-cycle periodicity (T/4). These results demonstrate that absorbance of two-photon dressed energy levels “ω ± 2ωι” can qualitatively map the AC Stark shift. These observations provide new insights into the control of spectral line shapes and open the way for the modulation of quantum optical interference in the laser-driven atom.
Optics Young Scientist Summit (OYSS)•Dec 29, 2023•0 citations