Nonlinear reflection and diffraction measurements have been performed on a GaAs/AlGaAs photonic-crystal waveguide patterned with a square lattice: The basis in the two-dimensional unit cell consists of rings of air in the dielectric matrix. The measured angles of diffracted second-harmonic beams agree with those predicted for nonlinear diffraction conditions. Results for second-harmonic intensities as a function of incidence angle, polarization, and pump wavelength show that the reflected second-harmonic signal is dominated by the crystalline symmetry of GaAs, whereas nonlinear diffraction is determined by the photonic-crystal structure.
© 2002 Optical Society of America
(190.2620) Nonlinear optics : Harmonic generation and mixing
(190.4390) Nonlinear optics : Nonlinear optics, integrated optics
(190.4400) Nonlinear optics : Nonlinear optics, materials
(190.4720) Nonlinear optics : Optical nonlinearities of condensed matter
Andrea Marco Malvezzi, Francesco Cattaneo, Gabriele Vecchi, Matteo Falasconi, Giorgio Guizzetti, Lucio Claudio Andreani, Filippo Romanato, Luca Businaro, Enzo Di Fabrizio, Adriana Passaseo, and Massimo De Vittorio, "Second-harmonic generation in reflection and diffraction by a GaAs photonic-crystal waveguide," J. Opt. Soc. Am. B 19, 2122-2128 (2002)