Sheng, YanWang, WenjieShiloh, RoyRoppo, VitoKong, YongfaArie, AdyKrolikowski, Wieslaw2015-09-172015-09-170003-6951http://hdl.handle.net/1885/15538We report on the observation of Čerenkov emission of a third-harmonic frequency in a two-dimensional nonlinear photonic crystal, where the second-order nonlinearity χ⁽²⁾ is spatially modulated by the reversal of ferroelectric domains. We analyze both spatial and polarization properties of the emitted radiation and find the results in agreement with our theoretical predictions.The authors acknowledge the financial supports from Australian Research Council and Israeli Science Foundation Grant No. 774/09.http://www.sherpa.ac.uk/romeo/issn/0003-6951..."Publishers version/PDF may be used on author's personal website, institutional website or institutional repository" from SHERPA/RoMEO site (as at 18/09/15). Copyright 2011 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters and may be found at https://dx.doi.org/10.1063/1.3602312Keywords: Emitted radiation; Ferroelectric domains; Nonlinear photonic crystals; Polarization properties; Second-order nonlinearity; Theoretical prediction; Third-harmonic frequencies; Third-harmonic generation; Two-dimensional nonlinear photonic crystal; Ferroelec2011-06-1710.1063/1.36023122016-02-24