Spatial and spectral properties of the pulsed second-harmonic generation   in a PP-KTP waveguide
  Spatial and spectral properties of the pulsed second harmonic generation in a periodically-poled KTP waveguide exploiting simultaneously the first, second, and third harmonics of periodic nonlinear modulation are analyzed. Experimental results are interpreted using a model based on finite elements method. Correlations between spatial and spectral properties of the fundamental and second-harmonic fields are revealed. Individual nonlinear processes can be exploited combining spatial and spectral filtering. Also the influence of waveguide parameters to the second-harmonic spectra is addressed. 
Radek Machulka, Ji\v{r}\'i Svozil\'ik, Jan Soubusta, Jan Pe\v{r}ina   Jr, Ond\v{r}ej Haderka
quant-ph physics.optics