Cerenkov third-harmonic generation in χ(2) nonlinear photonic crystal

We report on the observation of Cerenkov emission of a third-harmonic frequency in a two-dimensional nonlinear photonic crystal, where the second-order nonlinearity chi((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. (C) 2011 American Institute of Physics. [doi:10.1063/1.3602312]