skip to main content

DOE PAGESDOE PAGES

This content will become publicly available on December 4, 2016

Title: The Ultraviolet Surprise. Efficient Soft X-Ray High Harmonic Generation in Multiply-Ionized Plasmas

High-harmonic generation is a universal response of matter to strong femtosecond laser fields, coherently upconverting light to much shorter wavelengths. Optimizing the conversion of laser light into soft x-rays typically demands a trade-off between two competing factors. Reduced quantum diffusion of the radiating electron wave function results in emission from each species which is highest when a short-wavelength ultraviolet driving laser is used. But, phase matching—the constructive addition of x-ray waves from a large number of atoms—favors longer-wavelength mid-infrared lasers. We identified a regime of high-harmonic generation driven by 40-cycle ultraviolet lasers in waveguides that can generate bright beams in the soft x-ray region of the spectrum, up to photon energies of 280 electron volts. Surprisingly, the high ultraviolet refractive indices of both neutral atoms and ions enabled effective phase matching, even in a multiply ionized plasma. We observed harmonics with very narrow linewidths, while calculations show that the x-rays emerge as nearly time-bandwidth–limited pulse trains of ~100 attoseconds.
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [3] ;  [4] ;  [1] ;  [5] ;  [5] ;  [5] ;  [6] ;  [6] ;  [6] ;  [7] ;  [7] ;  [7] ;  [1] ;  [1] ;  [8] ;  [1] more »;  [1] ;  [1] « less
  1. Univ. of Colorado, Boulder, CO (United States)
  2. Univ. of Colorado, Boulder, CO (United States); Univ. of Salamanca (Spain)
  3. Center of Laseres Pulsados, Salamanca (Spain)
  4. National Tsing Hua Univ., Hsinchu (Taiwan)
  5. Cornell Univ., Ithaca, NY (United States)
  6. Temple Univ., Philadelphia, PA (United States)
  7. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  8. Univ. of Salamanca (Spain)
Publication Date:
OSTI Identifier:
1234578
Report Number(s):
LLNL-JRNL--676693
Journal ID: ISSN 0036-8075; TRN: US1600421
Grant/Contract Number:
AC52-07NA27344
Type:
Accepted Manuscript
Journal Name:
Science
Additional Journal Information:
Journal Volume: 350; Journal Issue: 6262; Journal ID: ISSN 0036-8075
Publisher:
AAAS
Research Org:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; 71 CLASSICAL AND QUANTUMM MECHANICS, GENERAL PHYSICS; 42 ENGINEERING; 71 CLASSICAL AND QUANTUMM MECHANICS, GENERAL PHYSICS; 70 PLASMA PHYSICS AND FUSION