Cfr. Caron et Rm. Potvliege, PHASE-MATCHING AND HARMONIC-GENERATION IN BESSEL-GAUSS BEAMS, Journal of the Optical Society of America. B, Optical physics, 15(3), 1998, pp. 1096-1106
Conversion efficiencies and far-field profiles for third-order harmoni
c generation in an atomic medium irradiated by an intense Bessel-Gauss
beam are calculated with an integral method. The calculation takes in
to account the nonperturbative variation of the atomic polarizabilitie
s. target depletion by photoionization, and the effect of the free ele
ctrons. Numerical results are presented for a pump beam of 355-nm wave
length and up to 3 x 10(13) W/cm(2) intensity incident on hydrogen. Th
ey are compared with equivalent results for a pure Gaussian pump beam.
Significant differences are found that originate from the different p
hase-matching properties and intensity profile of Bessel-Gauss beams.
(C) 1996 Optical Society of America.