The theoretical and experimental results of the investigation of an angular
distribution of second harmonic radiation generated by Bessel beam are pre
sented both for noncritical (temperature tuned LiNbO3 crystal) and critical
(types I and II, KDP crystals) phase-matching cases. The significance of t
ransverse and longitudinal phase-matching for SH generation is discussed. (
C) 1999 Published by Elsevier Science B.V. All rights reserved.