Fig. 1. Structures of the LN thin-film waveguide and the schemes of the phase matching process. E₁, β1 and E₂, β2 denote the electric field and transport constant of FW pump light and SHW signal light, respectively: (a) x-cut LN thin film; (b) z-cut LN thin film.

Fig. 2. Dispersion curves of EL+EL→EL phase-matching scheme in LN waveguide for various guided modes. The red star point represents the phase-matching point: (a) x-cut LN thin film; (b) z-cut LN thin film.

Fig. 3. (a) and (b) are normalized electric field distributions in x-cut LN thin film and z-cut LN thin film, respectively. (c) and (d) are energy flux density diagrams in x-cut LN thin film and z-cut LN thin film, respectively. The insets are the distributions of light intensity.

Fig. 4. (a) Phase-matching wavelength and efficiency of SHG in dependence on the thickness of LN thin film; (b) dependence of conversion efficiency on FW pump light intensity under large signal conditions.