
April 25, 2014 11:1 PSP Book - 9in x 6in 06-Rashid-A.-Ganeev-c06
216 Characterization of Plasma Harmonics
because a single atom during strong-field HHG can emit only one
photon of harmonic radiation. The increase of particle concentration
in general increases the efficiency of pump radiation absorption,
which means that the enhanced number of electron recombination
acts and, as a result, results in the enhanced HHG yield. However,
the increase of particle concentration is not always useful, because,
at high particle concentration, when the radiation is completely
absorbed, overall pulse energy may be insufficient to generate
even a single harmonic of maximum ...