Original Articles |
|
|
|
|
Frequencies-Selected Enhancement of the Extended High-Order Harmonic Generation Plateau from a United Two-Atom System Irradiated by a Combined Pulse |
CHEN Gao;CHEN Ji-Gen;YANG Yu-Jun;ZHU Hai-Yan;DU Wen-He;CHI Fang-Ping;ZHU Qi-Ren |
Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 |
|
Cite this article: |
CHEN Gao, CHEN Ji-Gen, YANG Yu-Jun et al 2005 Chin. Phys. Lett. 22 584-587 |
|
|
Abstract We present a high-order harmonic generation (HHG) spectrum from a united two-atom system exposed to a combined laser pulse, by numerically solving a one-dimensional time-dependent Schrödinger equation. The combined laser pulse is composed of a low-frequency femtosecond pulse and a high-frequency attosecond one with respective appropriate amplitudes. For a suitable inter-nuclear separation, the harmonic emission efficiencies near the second cutoff of the extended plateau can be effectively enhanced by more than four orders of magnitude compared with the case of the low-frequency pulse alone. Such a combined pulse irradiating on the united two-atom system ionizes each atom, in a large rate (but not to a too large ionization yield), mainly at a particular time-interval. When the ionized electron from an atom reaches at the vicinity of the other atom and recombines with it, significant HHG enhancement is achieved for particular harmonics. This result, to our knowledge, is one of the best up to now in the endeavor for dramatically extending the width and simultaneously enhancing the height of the plateau.
|
Keywords:
32.80.Rm
42.50.Hz
42.65.Ky
|
|
Published: 01 March 2005
|
|
PACS: |
32.80.Rm
|
(Multiphoton ionization and excitation to highly excited states)
|
|
42.50.Hz
|
(Strong-field excitation of optical transitions in quantum systems; multiphoton processes; dynamic Stark shift)
|
|
42.65.Ky
|
(Frequency conversion; harmonic generation, including higher-order harmonic generation)
|
|
|
|
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|