Generation of an isolated sub-40-as pulse using two-color laser pulses: Combined chirp effects

Abstract

In this paper, we theoretically discuss the combined chirp effects on the isolated attosecond generation when a model Ar is exposed to an intense 5-fs, 800-nm fundamental chirped pulse combined with a weak 10-fs, 1200-nm controlling chirped pulse. It shows that for the case of the chirp parameters β 1 = 6.1 (corresponding to the 800-nm field) and β 2 = 4.0 (corresponding to the 1200-nm field), both the harmonic cutoff energy and the supercontinuum can be remarkably extended resulting in a 663-eV bandwidth. Moreover, due to the introduction of the chirps, the short quantum path is selected to contribute to the harmonic spectrum. Finally, by superposing a properly selected harmonic spectrum in the supercontinuum region, an isolated pulse as short as 31 as (5 as) is generated without (with) phase compensation.

Quantum path control on the harmonic emission in the presence of a terahertz field

“…However, for the practical application, an isolated attosecond pulse obtained from the continuum HHG spectrum is more useful to trace the ultrafast electronic dynamics process. In order to produce an isolated attosecond pulse from a continuum harmonic spectrum, many methods aiming to control the movement of the emitted electron have been proposed, such as the few-cycle driving pulse scheme [12,13], the polarization gate scheme [14,15], the chirp pulse scheme [16,17], and the two-color or multi-color pulses scheme [18][19][20] etc. The shortest pulse duration achieved by these methods are about 80 as [12] and sub-10 as [20] from the experimental and the theoretical sides, respectively.…”

Low-energy structure in the ionization of argon: Comparison of experiment with theory

“…[17][18][19][20][21][22][23][24][25][26][27][28] In the dipole approximation and the length gauge, the TDSE is given by (atomic units are used throughout this paper unless stated otherwise)…”

Intensity enhancement in the molecular ionization and dissociation dynamics in the presence of noise

“…Usually, the ionization probabilities (IPs) and/or the dissociation probabilities (DPs) are critical to gain high signals or high yields for these photochemical and photophysical processes. Up to date, the enhancement of IPs and DPs can be achieved by using very high intense field [15], by the two or three-color field scheme [16], by varying the phase angle between the laser direction and the molecular axis [17], or by using the linearly or circularly polarized chirped laser pulses [18,19].…”