Coherent extreme-ultraviolet emission generated through frustrated tunnelling ionization

Yun, Hyeok; Mun, Je Hoi; Hwang, Sung In; Park, Seung Beom; Ivanov, Igor; Nam, Chang Hee; Kim, Kyung Taec

doi:10.1038/s41566-018-0255-8

Cited by 47 publications

(40 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finally, we observe a weak spectral tilt of the odd harmonics as a function of the delay. We note that we do not find any signatures of XUV free induction decay [30] or HHG by frustrated tunneling ionization [31] below the ionization threshold.…”

Section: Methodscontrasting

confidence: 65%

The Role of Electron Trajectories in XUV-Initiated High-Harmonic Generation

et al. 2019

View full text Add to dashboard Cite

High-harmonic generation spectroscopy is a powerful tool for ultrafast spectroscopy with intrinsic attosecond time resolution. Its major limitation—the fact that a strong infrared driving pulse is governing the entire generation process—is lifted by extreme ultraviolet (XUV)-initiated high-harmonic generation (HHG). Tunneling ionization is replaced by XUV photoionization, which decouples ionization from recollision. Here we probe the intensity dependence of XUV-initiated HHG and observe strong spectral frequency shifts of the high harmonics. We are able to tune the shift by controlling the instantaneous intensity of the infrared field. We directly access the reciprocal intensity parameter associated with the electron trajectories and identify short and long trajectories. Our findings are supported and analyzed by ab initio calculations and a semiclassical trajectory model. The ability to isolate and control long trajectories in XUV-initiated HHG increases the range of the intrinsic attosecond clock for spectroscopic applications.

show abstract

Section: Methodscontrasting

confidence: 65%

The Role of Electron Trajectories in XUV-Initiated High-Harmonic Generation

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The approximations employed in the derivation of the formula limit it, in principle, to laser fields much stronger than the Coulomb field and small ε, but it was apparently sufficient to reproduce the experimental results of Nubbemeyer et al [4]. More recent work on the helium target was reported by Yun et al [6].…”

Section: Introductionmentioning

confidence: 90%

Ellipticity dependence of excitation and ionization of argon atoms by short-pulse infrared radiation

et al. 2020

View full text Add to dashboard Cite

When atoms or molecules are exposed to strong short-pulse infrared radiation, ionization as well as "frustrated tunneling ionization" (FTI) can occur, in which some of the nearly freed electrons recombine into the initial ground or an excited bound state. We analyze the ellipticity dependence of the relative signals that are predicted in a single-active electron approximation (SAE), the validity of which is checked against a parameter-free multi-electron R-matrix (close-coupling) with time dependence approach. We find good agreement between the results from both models, thereby providing confidence in the SAE model potential to treat the process of interest. Comparison of the relative excitation probabilities found in our numerical calculations with the predictions of Landsman et al. (New Journal of Physics 15 (2013) 013001) and Zhao et al. (Optics Express 27 (2019) 21689) reveals good agreement with the former for short pulses. For longer pulses, the ellipticity dependence becomes wider than that obtained from the Landsman et al. formula, but we do not obtain the increase compared to linearly polarized radiation predicted by Zhao et al.

show abstract

“…It was shown in [13,25] that the Schrödinger equation in the two-level approximation can be written as the equation of an oscillator with the time-dependent frequency (i.e. as a parametric oscillator) driven by an external force (see equation (9) in [25]). This frequency is the nonlinear term leading to the harmonic generation and it is written as…”

Section: Two-level Model For Transition To the Rydberg Statementioning

confidence: 99%

“…One of the core assumptions of the SFA is to neglect the influence of bound excited states in the highharmonic generation. However, as experiments get more sophisticated, coherent XUV emission processes involving these states are being discovered and investigated: XUV free-induction decay, either excited by singlephoton [5,6] or multiphoton absorption [7], high-order harmonic generation (HHG) from excited Rydberg states [8] or from frustrated tunnel ionization [9]. The XUV emission constitutes a spectroscopic signature of the strong-field dynamics involving the bound excited states, and could thus be used to resolve their dynamics.…”

Section: Introductionmentioning

confidence: 99%

Hyper-Raman lines emission concomitant with high-order harmonic generation

et al. 2019

View full text Add to dashboard Cite

Hyper-Raman lines (HRL) resulting from strong-field light-matter interaction have been predicted theoretically in the 1990s but never identified in high-order harmonic generation experiments. Here, we use a combination of 800 and 400 nm laser pulses to control independently the two processes required for the hyper-Raman emission: creation of a coherence between two electronic states and laser-dressing of these states. As a result we observe simultaneously high-order harmonics, XUV free induction decay and HRL. We investigate experimentally and numerically the properties of this novel emission source. It can be of high interest, amongst others, for high-resolution spatio-temporal spectroscopy of excited electronic states in the same fashion high-order harmonics generation provides it for ground state.

show abstract

Coherent extreme-ultraviolet emission generated through frustrated tunnelling ionization

Cited by 47 publications

References 33 publications

The Role of Electron Trajectories in XUV-Initiated High-Harmonic Generation

The Role of Electron Trajectories in XUV-Initiated High-Harmonic Generation

Ellipticity dependence of excitation and ionization of argon atoms by short-pulse infrared radiation

Hyper-Raman lines emission concomitant with high-order harmonic generation

Contact Info

Product

Resources

About