title: Multiple Čerenkov second-harmonic waves in a two-dimensional nonlinear photonic structure.
abstract: We report simultaneous generation of multiple conical second-harmonic waves in a two-dimensional nonlinear photonic structure when illuminated by two overlapping noncollinear fundamental beams. We show that this phenomenon is caused by the nonlinear Čerenkov radiation emitted due to the interaction of photons from each constituent fundamental beam as well as the virtual one propagating along the bisector of the two beams. In addition, by studying the asymmetric geometry of the interaction, we uniquely verify the effects of reciprocal vectors on the Čerenkov-type second-harmonic generation in nonlinear photonic structures.
authors.affiliation: Laser Physics Center, Research School of Physics and Engineering, Australian National University, ACT 0200, Australia.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Sheng
authors.forename: Yongfa
authors.initials: Y
authors.lastname: Kong
authors.forename: Ady
authors.initials: A
authors.lastname: Arie
authors.forename: Wieslaw
authors.initials: W
authors.lastname: Krolikowski