Summary: IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 45, NO. 11, NOVEMBER 2009 1465
Cerenkov-Type Second-Harmonic Generation in
Two-Dimensional Nonlinear Photonic Structures
Solomon Mois Saltiel, Yan Sheng, Noa Voloch-Bloch, Dragomir N. Neshev, Wieslaw Krolikowski, Ady Arie,
Kaloian Koynov, and Yuri S. Kivshar
Abstract--We study the Cerenkov-type second-harmonic gen-
eration in several different two-dimensional nonlinear photonic
structures formed in birefringent crystals with the 3m symmetry.
Depending on the degree of birefringence, we observe either
single or double Cerenkov-like second-harmonic rings. We discuss
the properties of these parametrically generated rings and show
that their sixfold azimuthal modulation is associated with the
hexagonal symmetry of the individual ferroelectric domains.
Index Terms--Cerenkov phase-matching, nonlinear diffraction,
quasi-phase-matching, second-harmonic generation.
I T IS well known that second-harmonic generation (SHG)
can be achieved by many different ways depending on the
geometry of the wave phase matching (e.g., birefringence-in-
duced phase matching or quasi-phase matching (QPM), input