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Lasers, Extreme UV and Soft X-ray

  1. Joseph Nilsen

Published Online: 15 JUL 2004

DOI: 10.1002/3527600434.eap628

Encyclopedia of Applied Physics

Encyclopedia of Applied Physics

How to Cite

Nilsen, J. 2004. Lasers, Extreme UV and Soft X-ray. Encyclopedia of Applied Physics. .

Author Information

  1. Lawrence Livermore National Laboratory, Livermore, CA

Publication History

  1. Published Online: 15 JUL 2004


Two decades ago, very large sources such as the building size ICF lasers were used as the energy sources to drive the first X-ray lasers. Tremendous progress has been made over the last two decades to produce tabletop, high-repetition rate X-ray lasers that can be used as tools for applications. With the use of high-reflectivity multilayer mirrors, many of the standard optical techniques such as interferometry can be extended to the soft X-ray regime between wavelengths of 10 and 50 nm. The dominant X-ray laser schemes are the monopole collisional excitation lasers either driven by chirped pulse amplification (CPA) laser systems or capillary discharge. The CPA systems drive lasing in neon-like or nickel-like ions, typically in the 10- to 30-nm range, while the capillary system is currently limited to driving neon-like ions at a longer wavelength near 50 nm. Most researchers use nickel-like ion lasers near 14 nm because they are well matched to the Mo:Si multilayer mirrors, which have peak reflectivity near 13 nm, and are an essential component of applications such as X-ray laser interferometry.


  • neon-like;
  • nickel-like;
  • hydrogen-like;
  • collisional excitation;
  • recombination