Abstract

In [1] possibility to obtain the diffraction-limited beam from OPG pumped by two- and three- intersecting beams has been shown. Recently this technique we have modified using Bessel beam as the pump for OPO and OPG. The Bessel beam is a special case of the conical beam (beam with annular spectrum) when the plane waves compiling the conical beam are of the same phase. A particular feature of parametric conversion of conical beam is simultaneous multiple noncollinear phase–matching of all plane waves compiling a cone. An excited signal wave propagates in the direction close to cone axis. That we have demonstrated in the case of OPO with coherent and partially incoherent conical pump [2]. We have shown that conical pump gives rise to a striking directivity of excited radiation. In all parametrical convertors investigated the optical patterns of the output radiation had structure determined by the multiple noncollinear phase matching.

© 1998 IEEE