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Title: Enhanced Harmonic Generation from Expanding Clusters

Abstract

We report controlled enhancement of optical third harmonic generation (THG) from hydrodynamically expanding clusters of {approx}6x10{sup 5} noble-gas atoms several hundred femtoseconds following ionization and heating by ultrashort pump pulses. This resonant enhancement is more pronounced for orthogonal than for parallel pump-probe polarizations, a consequence of faster cluster expansion along the pump polarization. Simulations show that the nonlinear susceptibility {chi}{sup (3)} of the individual clusters and the coherence length of the clustered plasma medium are optimized nearly simultaneously as the clusters expand, and both contribute to the observed THG enhancement. This dual enhancement mechanism may be scalable to relativistic probe intensity and to generation of high-order harmonics in the soft-x-ray regime.

Authors:
; ; ; ;  [1]
  1. FOCUS Center, Department of Physics, University of Texas at Austin, Austin, Texas 78712-1081 (United States)
Publication Date:
OSTI Identifier:
20951124
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 98; Journal Issue: 12; Other Information: DOI: 10.1103/PhysRevLett.98.123902; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ATOMIC CLUSTERS; CLUSTER EXPANSION; COHERENCE LENGTH; HARMONIC GENERATION; HARMONICS; HEATING; IONIZATION; NONLINEAR PROBLEMS; PLASMA; POLARIZATION; PROBES; PULSES; RARE GASES; RELATIVISTIC RANGE; SIMULATION; SOFT X RADIATION

Citation Formats

Shim, B., Hays, G., Zgadzaj, R., Ditmire, T., and Downer, M. C.. Enhanced Harmonic Generation from Expanding Clusters. United States: N. p., 2007. Web. doi:10.1103/PHYSREVLETT.98.123902.
Shim, B., Hays, G., Zgadzaj, R., Ditmire, T., & Downer, M. C.. Enhanced Harmonic Generation from Expanding Clusters. United States. doi:10.1103/PHYSREVLETT.98.123902.
Shim, B., Hays, G., Zgadzaj, R., Ditmire, T., and Downer, M. C.. Fri . "Enhanced Harmonic Generation from Expanding Clusters". United States. doi:10.1103/PHYSREVLETT.98.123902.
@article{osti_20951124,
title = {Enhanced Harmonic Generation from Expanding Clusters},
author = {Shim, B. and Hays, G. and Zgadzaj, R. and Ditmire, T. and Downer, M. C.},
abstractNote = {We report controlled enhancement of optical third harmonic generation (THG) from hydrodynamically expanding clusters of {approx}6x10{sup 5} noble-gas atoms several hundred femtoseconds following ionization and heating by ultrashort pump pulses. This resonant enhancement is more pronounced for orthogonal than for parallel pump-probe polarizations, a consequence of faster cluster expansion along the pump polarization. Simulations show that the nonlinear susceptibility {chi}{sup (3)} of the individual clusters and the coherence length of the clustered plasma medium are optimized nearly simultaneously as the clusters expand, and both contribute to the observed THG enhancement. This dual enhancement mechanism may be scalable to relativistic probe intensity and to generation of high-order harmonics in the soft-x-ray regime.},
doi = {10.1103/PHYSREVLETT.98.123902},
journal = {Physical Review Letters},
number = 12,
volume = 98,
place = {United States},
year = {Fri Mar 23 00:00:00 EDT 2007},
month = {Fri Mar 23 00:00:00 EDT 2007}
}