title: Spatiotemporal toroidal waves from the transverse second-harmonic generation.
abstract: We study the second-harmonic generation via transversely matched interaction of two counterpropagating ultrashort pulses in chi(2) photonic structures. We show that the emitted second-harmonic wave attains the form of spatially expanding toroid with the initial thickness given by the cross correlation of the pulses. We demonstrate the formation of such toroidal waves in crystals with random ferroelectric domains as well as in annularly poled nonlinear photonic structures.
authors.affiliation: Nonlinear Physics Center and Laser Physics Center, Center for Ultra-High Bandwidth Devices for Optical Systems, (CUDOS), Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT, Australia.
authors.forename: Solomon M
authors.initials: SM
authors.lastname: Saltiel
authors.forename: Dragomir N
authors.initials: DN
authors.lastname: Neshev
authors.forename: Robert
authors.initials: R
authors.lastname: Fischer
authors.forename: Wieslaw
authors.initials: W
authors.lastname: Krolikowski
authors.forename: Ady
authors.initials: A
authors.lastname: Arie
authors.forename: Yuri S
authors.initials: YS
authors.lastname: Kivshar