Amplification of short-wavelength radiation is advantageously done across a plasma medium. The latter can be produced either using a powerful pump laser or by means of a capillary discharge. The main advantages of this scheme are the ultra-narrow linewidth (Q ≈ 10,000), the full temporal coherence, and the compact footprint. These figures-of-merit are complementary to those of short-wavelength free-electron lasers (xFEL). xFEL facilities are currently available in a few sites, due to the remarkable cost of construction and operation. After a general introduction on laboratory-scale short-wavelength lasers, a comparison with state-of-art xFEL
will be done.
"Comparison of laboratory-scale XUV laser with xFELs", Proc. SPIE 8678, Short-Wavelength Imaging and Spectroscopy Sources, 867806 (11 December 2012); doi: 10.1117/12.2008733; https://doi.org/10.1117/12.2008733