Subfemtosecond pulses

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.…”

High-order harmonic generation spectra and isolated attosecond pulse generation with a two-color time delayed pulse

“…However, the strategy of increasing the field amplitude is limited by the saturation effect due to depletion of the ground state [20,21], while the one of reducing the central frequency ω 0 is limited by the reduced harmonic yield due to the longer electron excursion times [22,23]. Therefore, recently, these two issues have been addressed by using the two or multi-color laser field scheme [24][25][26][27]. Within this framework, Zeng et al [28] theoretically obtain an isolated 65as pulse through the combination of an 800 nm fundamental field and a 400 nm controlling field.…”

Adaptive Femtosecond Quantum Control

“…It allows to address stereochemical aspects in quantum control such as chiral selectivity, where polarization-shaped laser pulses are a crucial ingredient [31][32][33][34][35][36]. The optical control of lattice vibrations [156] and the generation and characterization of attosecond light pulses [130,131] are further examples of numerous new perspectives.…”

“…The application of time-dependent polarization states that can thus be generated has been suggested, for example, for the generation [130,131] and characterization [132] of attosecond light pulses, for the optical control of lattice vibrations [133] and the selective production of enantiomers [31][32][33][34][35][36]. The adaptive shaping of complex polarization profiles within a learning loop has been demonstrated by our group in an optical demonstration experiment [134], and Oron et al have used spectral modulation of phase and polarization direction in coherent anti-Stokes Raman spectroscopy (CARS) [135].…”