Interference of traveling nondiffracting beams

We study numerically the interference resulting from the superposition of t wo Bessel beams propagating in free space. We discuss how to obtain such be ams and show the existence of the self-imaging effect during propagation. T he evolution of the superimposed Bessel beams is analyzed on the basis of t he evolution of the individual beams. Our exact numerical predictions contr adict previous approximated analytical treatments, showing that they can le ad to quantitatively wrong results and misleading conclusions. (C) 1998 Opt ical Society of America.