Dynamically enhanced Autler-Townes splitting by orthogonal XUV Fields

Abstract Based on numerical solutions of the time-dependent Schrödinger equation, we have theoretically investigated the photoelectron spectrum of hydrogen atoms ionized by a pair of ultrashort, intense, and orthogonally polarized laser pulses with a relative time delay in a pump-probe configuration. The pump pulse resonantly excites electrons from the 1s and 2p levels, inducing Rabi oscillations. The resulting dynamically enhanced Autler-Townes (AT) splitting is observed in the photoelectron energy spectrum upon interaction with the second probe pulse. In contrast to previous parallel-polarization scheme, the proposed orthogonal-polarization configuration enables the resolution of dynamically enhanced AT splitting over a considerably wider range of probe photon energies.