scholarly journals Study in momentum space of phase-dependent effects on ionization of hydrogen atom interacting with short infrared laser pulses

2021 ◽  
Author(s):  
Fréderic ONGONWOU ◽  
Hugues Merlain TETCHOU ◽  
Thierry Blanchard EKOGO ◽  
Bakari ABDOURAMAN ◽  
Moïse Godefroy KWATO
Keyword(s):  
Laser Pulse ◽  
Coulomb Potential ◽  
Momentum Space ◽  
Bound States ◽  
Laser Pulses ◽  
Infrared Laser ◽  
Time Dependent ◽  
Basis Set ◽  
Angular Distributions ◽  
Carrier Envelope Phase

We examine above-threshold ionization spectra of model atomic hydrogen in short infrared laser pulses by solving the one-electron time-dependent Schr\“odinger equation in momentum space. To bypass the difficulty of solving the time-dependent Schr\”odinger equation with the interacting nonlocal Coulomb potential, we have recently formulated an alternative \emph{ab initio} approach [Ongonwou et al. Annals of Physics {\bf 375}, 471 (2016)], which is relied on the expansion of the atomic wavefunction and the interacting nonlocal Coulomb potential on a discrete basis set of Coulomb Sturmians in momentum space. As far as short infrared laser pulses are concerned, we have numerically evaluated the photoelectron momentum distributions, angular distributions and bound states populations. The results obtained from our accurate new computationally method are compared against predictions of other time-dependent calculations in the literature. This new theoretical model shows its sensitivity to the carrier-envelope phase of the laser pulse and captures the left-right dependence of the emitted photoelectrons momentum and angular distributions. More precisely, short pulses manifest significant dependence of the differential ionization probability on carrier-envelope phase of the laser pulse and broken forward-backward symmetry in the angular distributions.

scholarly journals Characterizing the carrier-envelope phase stability of mid-infrared laser pulses by high harmonic generation in solids

2020 ◽  
Vol 28 (12) ◽  
pp. 17161
Author(s):  
A. Leblanc ◽  
P. Lassonde ◽  
Gilles Dalla-Barba ◽  
E. Cormier ◽  
H. Ibrahim ◽  
...  
Keyword(s):  
Harmonic Generation ◽  
Phase Stability ◽  
High Harmonic ◽  
High Harmonic Generation ◽  
Laser Pulses ◽  
Infrared Laser ◽  
Mid Infrared ◽  
Carrier Envelope Phase

scholarly journals Linear and nonlinear absolute phase effects in interactions of ulrashort laser pulses with a metal nano-layer or with a thin plasma layer

2007 ◽  
Vol 25 (3) ◽  
pp. 379-390 ◽  
Author(s):  
S. Varró
Keyword(s):  
Laser Pulse ◽  
Phase Difference ◽  
Plasma Layer ◽  
Thin Foil ◽  
Laser Pulses ◽  
Thomson Scattering ◽  
Carrier Envelope Phase ◽  
Absolute Phase ◽  
High Intensity Laser ◽  
Order Of Magnitude

It has been shown that in the scattered radiation, generated by an ultrashort laser pulse impinging on a metal nano-layer, non-oscillatory wakefields appears with a definite sign. The magnitude of these wakefields is proportional to the incoming field strength, and the definite sign of them is governed by the cosine of the carrier-envelope phase difference of the incoming pulse. When we let such a Wakefield excite the electrons of a secondary target (say an electron beam, a metal surface or a gas jet), we can obtain 100 percent modulation in the electron signal in a given direction. This scheme can serve as a basis for the construction of a robust linear carrier-envelope phase difference meter. At relativistic laser intensities, the target is considered as a plasma layer in vacuum produced from a thin foil by a prepulse, which is followed by the main high-intensity laser pulse. The nonlinearities stemming from the relativistic kinematics lead to the appearance of higher-order harmonics in the scattered spectra. In general, the harmonic peaks are downshifted due to the presence of an intensity-dependent factor. This phenomenon is analogous to the famous intensity-dependent frequency shift in the nonlinear Thomson scattering on a single electron. In our analysis, an attention has also been paid to the role of the carrier-envelope phase difference of the incoming few-cycle laser pulse. It is also shown that the spectrum has a long tail where the heights of the peaks vary practically within one order of magnitude forming a quasi-continuum. Fourier synthesizing the components from this plateau region attosecond pulses has obtained.

scholarly journals Carrier-envelope phase dependence of molecular harmonic spectral minima induced by mid-infrared laser pulses

2015 ◽  
Vol 23 (18) ◽  
pp. 23834 ◽  
Author(s):  
Pidong Hu ◽  
Yueping Niu ◽  
Yang Xiang ◽  
Shangqing Gong ◽  
Chengpu Liu
Keyword(s):  
Laser Pulses ◽  
Infrared Laser ◽  
Phase Dependence ◽  
Mid Infrared ◽  
Carrier Envelope Phase

Bayesian approach for the optimal control of high-order harmonics for the generation of ultrashort attosecond laser pulses

2021 ◽  
Author(s):  
Wei-Teng Wang ◽  
Yae-Lin Sheu ◽  
Shih-I Chu
Keyword(s):  
Laser Pulse ◽  
Laser Field ◽  
Pseudospectral Method ◽  
Laser Pulses ◽  
Optimization Method ◽  
High Order ◽  
Time Dependent ◽  
Bayesian Optimization ◽  
Time Frequency ◽  
Isolated Attosecond Pulse

Abstract We present an efficient and powerful method to optimize the production of high-order harmonic generation (HHG) and ultrashort single attosecond laser pulses. The system under investigation is the helium atoms that are exposed to the combination of chirped two-color mid-IR laser field and its 34th harmonic. The time-dependent Schrödinger equation is solved accurately and efficiently by means of the time-dependent generalized pseudospectral method and the time-frequency spectrum is obtained by the wavelet transform. We extend the machine-learning based optimization method, called Bayesian optimization (BO), to optimize the incident laser pulse to generate ultrashort attosecond laser pulse successfully for the first time. It is shown that the intensity of HHG power spectrum from the plateau region to the cutoff is enhanced by the optimized laser field by several orders of magnitude. Further, an ultrafast isolated attosecond pulse of 10 attosecond can be generated efficiently by superposing the plateau harmonics.

scholarly journals Carrier-envelope-phase measurement of few-cycle mid-infrared laser pulses using high harmonic generation in ZnO

2020 ◽  
Vol 28 (5) ◽  
pp. 7314 ◽  
Author(s):  
Richard Hollinger ◽  
Dominik Hoff ◽  
Philipp Wustelt ◽  
Slawomir Skruszewicz ◽  
Yinyu Zhang ◽  
...  
Keyword(s):  
Harmonic Generation ◽  
Phase Measurement ◽  
High Harmonic ◽  
High Harmonic Generation ◽  
Laser Pulses ◽  
Infrared Laser ◽  
Mid Infrared ◽  
Carrier Envelope Phase

scholarly journals Numerical solutions of the Maung-Norbury-Kahana equation with the coulomb potential in momentum space

2017 ◽  
Vol 64 (1) ◽  
pp. 8 ◽  
Author(s):  
Jiao-Kai Chen
Keyword(s):  
Coulomb Potential ◽  
Momentum Space ◽  
Bound States ◽  
Numerical Solutions ◽  
Complicated Form

In this paper, the numerical solutions of the Maung-Norbury-Kahana equation which has the complicated form of the eigenvalues are presented. Taken as examples, the bound states $e^+e^-$, $\mu^+\mu^-$ and $\mu^+e^-$ are discussed by employing the Maung-Norbury-Kahana equation with the Coulomb potential.

scholarly journals Controlling Quantum Wave Packet of Electronic Motion on Field-Dressed Coulomb Potential of H2+ by Carrier-Envelope Phase-Dependent Strong Field Laser Pulses

2021 ◽  
Author(s):  
Mohammad Noh Daud
Keyword(s):  
Coulomb Potential ◽  
Strong Field ◽  
Laser Pulses ◽  
Time Duration ◽  
Carrier Envelope Phase ◽  
Free Region ◽  
Field Free Region ◽  
Electronic Motion ◽  
Quantum Wave ◽  
The Right

Solving numerically a non-Born-Oppenheimer time-dependent Schrödinger equation to study the dissociative-ionization of H subjected to strong field six-cycle laser pulses (I = 4 × 10 W/cm, λ = 800 nm) leads to newly ultrafast images of electron dynamics in H. The electron distribution in H oscillates symmetrically with laser cycle with θ + π periodicity and gets trapped between two protons for about 8 fs by a Coulomb potential well. Nonetheless, this electron symmetrical distribution breaks up for the H internuclear separation larger than 9 a.u. in the field-free region at a time duration of 24 fs as a result of the distortion of Coulomb potential where the ejected electron preferentially localizes in one of the double-well potential separated by the inner Coulomb potential barrier. Moreover, controlling laser carrier-envelope phase θ enables one to generate the highest total asymmetry A of 0.75 and -0.75 at 10 and 190, respectively, associated with the electron preferential directionality being ionized to the left or the right paths along the H molecular axis. Thus the laser-controlled electron slightly reorganizes its position accordingly to track the shift in the position of the protons despite much heavier the proton’s mass.

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