Universality in odd-even harmonic generation and application in terahertz waveform sampling
arXiv:2301.02910 · doi:10.1103/PhysRevA.108.023109
Abstract
Odd-even harmonics emitted from a laser-target system imprint rich, subtle information characterizing the system's dynamical asymmetry, which is desirable to decipher. In this Letter, we discover a simple universal relation between the odd-even harmonics and the asymmetry of the THz-assisted laser-atomic system -- atoms in a fundamental mid-IR laser pulse combined with a THz laser. First, we demonstrate numerically and then analytically formulize the harmonic even-to-odd ratio as a function of the THz electric field, the source of the system's asymmetry. Notably, we suggest a scaling that makes the obtained rule universal, independent of the parameters of both the fundamental pulse and atomic target. This universality facilitates us to propose a general pump-probe scheme for THz waveform sampling from the even-to-odd ratio, measurable within a conventional compact setup.
References in corpus (4)
- Accurate retrieval of structural information from laser-induced photoelectron and high-harmonic spectra by few-cycle laser pulses
- Extraction of the species dependent dipole moment from high-order harmonic spectra in rare gas atoms
- Terahertz-induced high-order harmonic generation and nonlinear charge transport in graphene
- High order Brunel harmonics and supercontinuum formed by a weak optical pump in presence of a strong terahertz field