Nonlinear coherence effects in transient-absorption ion spectroscopy with stochastic extreme-ultraviolet free-electron laser pulses

Abstract

We demonstrate time-resolved nonlinear extreme-ultraviolet absorption spectroscopy on multiply charged ions, here applied to the doubly charged neon ion, driven by a phase-locked sequence of two intense free-electron laser pulses. Absorption signatures of resonance lines due to 2$p$--3$d$ bound--bound transitions between the spin-orbit multiplets ${}^3$P${}_{0,1,2}$ and ${}^3$D${}_{1,2,3}$ of the transiently produced doubly charged Ne${}^{2+}$ ion are revealed, with time-dependent spectral changes over a time-delay range of $(2.4\pm 0.3)\text{fs}$. Furthermore, we observe 10-meV-scale spectral shifts of these resonances owing to the AC Stark effect. We use a time-dependent quantum model to explain the observations by an enhanced coupling of the ionic quantum states with the partially coherent free-electron-laser radiation when the phase-locked pump and probe pulses precisely overlap in time.

References in corpus (7)

• Control of quantum phenomena: Past, present, and future
• Lorentz meets Fano spectral line shapes: A universal phase and its laser control
• Transient absorption and reshaping of ultrafast XUV light by laser-dressed helium
• Theory of attosecond transient absorption spectroscopy of strong-field-generated ions
• Noisy pulses enhance temporal resolution in pump-probe spectroscopy
• Coherent ultrafast core-hole correlation spectroscopy: x-ray analogues of multidimensional NMR
• Attosecond interferometry with self-amplified spontaneous emission of a free-electron laser

Cited by in corpus (6)

• Atomic, molecular and optical physics applications of longitudinally coherent and narrow bandwidth Free-Electron Lasers
• Compact intense extreme-ultraviolet source
• Strong-field quantum control in the extreme ultraviolet using pulse shaping
• Propagation-assisted generation of intense few-femtosecond high-harmonic pulses
• Time-Resolved Ultrafast Transient Polarization Spectroscopy to Investigate Nonlinear Processes and Dynamics in Electronically Excited Molecules on the Femtosecond Time Scale
• Non-linear self-driven spectral tuning of Extreme Ultraviolet Femtosecond Pulses in monoatomic materials