Aa. Kaminskii et al., NEW OPTICAL PHENOMENA IN LASER INSULATING CRYSTAL HOSTS WITH 3RD-ORDER NONLINEAR SUSCEPTIBILITIES, Physica status solidi. a, Applied research, 148(2), 1995, pp. 619-628
Besides the multiple cascade stimulated Raman scattering, new optical
nonlinear phenomena in laser crystal hosts are observed, in particular
, in monoclinic KY(WO4)(2) and KGd(WO4)(2) compounds, under high densi
ty visible nano- and picosecond laser excitation in single-pass geomet
ry. The first one is a ''laser rainbow'', a multiple co-axial ring Sto
kes Raman emission by four-wave mixing parametric processes, and the s
econd one is the self-trapping (filamentation) of the propagating lase
r pump beam and Stokes generation.