High order Brunel harmonics and supercontinuum formed by a weak optical pump in presence of a strong terahertz field

authored by

Ihar Babushkin, Ayhan Demircan, Uwe Morgner, A. Savel'Ev

Abstract

Brunel harmonics appear in the optical response of an atom in process of laser-induced ionization, when the electron leaves the atom and is accelerated in the strong optical field. In contrast to recollision-based harmonics, the Brunel mechanism does not require the electron returning to the core. Here we show that in the presence of a strong ionizing terahertz (THz) field, even a weak driving field at the optical frequencies allow for generating Brunel harmonics effectively. The strong ionizing THz pump suppresses recollisions, making Brunel dominant in a wide spectral range. High-order Brunel harmonics may form a coherent carrier-envelope-phase insensitive supercontinuum, compressible into an isolated pulse with the duration down to 100 attoseconds.

Organisation(s)

Institute of Quantum Optics
PhoenixD: Photonics, Optics, and Engineering - Innovation Across Disciplines

External Organisation(s)

Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy im Forschungsbund Berlin e.V. (MBI)
Lebedev Physical Institute of the Russian Academy of Sciences (LPI RAS)

Type

Preprint

Publication date

10.05.2021

Publication status

E-pub ahead of print

Electronic version(s)

http://de.arxiv.org/abs/2105.04627 (Access: Open)