Solitary-wave vortices in quadratic nonlinear media Torres, Juan P. ; Soto-Crespo, J. M. ; Torner, Lluis ; Petrov, Dmitri V. Abstract Publication: Journal of the Optical Society of America B Optical Physics Pub Date: February 1998 DOI: 10.1364/JOSAB.15.000625 Bibcode: 1998JOSAB..15..625T