Analysis of interference in attosecond transient absorption in adiabatic condition

We simulate the transient absorption of attosecond pulses of infrared-laser-dressed atoms by considering a three-level system in the adiabatic approximation. The delay-dependent interference features are investigated from the perspective of the coherent interaction processes between the attosecond pulse and the quasiharmonics. We find that many features of the interference fringes in the absorption spectra of the attosecond pulse can be attributed to the coherence phase difference. However, the modulation signals of laser-induced sidebands of the dark state are found to be related to the population dynamics of the dark state by the dressing field.