High-order harmonic generation in rare gases with intense subpicosecond dye laser pulses

A systematic study of high-order harmonic generation in rare gases has been made for the first time with intense (2*10¹⁴ W cm^-2, 616 nm) dye laser pulses, where the harmonic radiation up to the 41st order in He, the 37th in Ne, the 19th in Ar, the 17th in Kr and the 13th in Xe is observed. The individual harmonic distributions represent a plateau that is preceded by an intensity minimum and formed from an energy region near the ionization limit. The importance of dynamic resonances and shifting ionization limit is discussed to illustrate the plateau formation process observed.