Open AccessBrunel harmonics generated from ionizing clusters by few-cycle laser pulses
Author(s) -
Xiaohui Gao,
Bonggu Shim,
M. C. Downer
Publication year - 2019
Publication title -
optics letters/optics index
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.524
H-Index - 272
eISSN - 1071-2763
pISSN - 0146-9592
DOI - 10.1364/ol.44.000779
Subject(s) - harmonics , high harmonic generation , laser , ionization , optics , harmonic , physics , extreme ultraviolet , atomic physics , plasma , cluster (spacecraft) , ion , quantum mechanics , voltage , computer science , programming language
We study theoretically harmonic generation from ionizing nano-clusters irradiated by intense few-cycle laser pulses and identify a Brunel-type harmonic generation mechanism that originates from subcycle ionization dynamics in clusters. Compared to Brunel harmonics in gases, the spectra are shifted toward odd-order harmonics of Mie frequency ω M due to efficient excitation of Mie oscillations. Considering the appreciable single-cluster harmonic yield and the relaxed phase-matching condition in overdense clustered plasmas, clusters driven by few-cycle laser pulses can be a promising source of vacuum-ultraviolet radiation.