title: The effect of pump-2 laser on Autler-Townes splitting in photoelectron spectra of K2 molecule.
abstract: We theoretically investigated Autler-Townes (AT) splitting in the photoelectron spectra of a four-level ladder K2 molecule driven by pump1-pump2-probe pulses by employing the time-dependent wave packet approach. The effect of pump-2 laser intensity and wavelength on AT splitting was studied for the first time. Triple splitting with asymmetric profiles arises because of the non-resonant excitation. The triple splitting transforms to double splitting when pump-2 detuning approaches ±1/2 times of pump-1 Rabi frequency. The splitting between two side band peaks in the triplet or doublet does not change with the pump-2 laser wavelength. The three peaks shift to a lower energy with a different shift as pump-2 wavelength increases. The magnitude of AT splitting increases with increasing pump-2 laser intensity. The asymptotic behavior of AT splitting with the pump-2 laser intensity are interesting at the threshold point of the near resonant region and far-off resonant region.
authors.affiliation: School of Electric Engineering, University of South China, Hengyang 421001, P. R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Guo
authors.forename: Xingqiang
authors.initials: X
authors.lastname: Lu
authors.forename: Xinlin
authors.initials: X
authors.lastname: Wang
authors.forename: Hongbin
authors.initials: H
authors.lastname: Yao