A theoretical analysis of a traveling-wave difference-frequency-generation problem in three-dimensional space was performed. We found that, under a suitable hypothesis of low conversion efficiency in anisotropic nonlinear crystals, the nonlinear interaction gives a diffraction-free propagation condition for particular J<sub>0</sub> Bessel beams and modulation instability phenomena for other J<sub>0</sub> Bessel beams.
© 2000 Optical Society of America
S. Severini, C. Sibilia, and M. Bertolotti, "Transverse effects in a parametric downconversion process in three dimensions," J. Opt. Soc. Am. B 17, 580-585 (2000)