Reverse proton exchange for frequency doubling in lithium niobate waveguides

Reverse proton exchange is a promising technique for the fabrication of nonlinear waveguides in unpoled lithium niobate (LN). We have investigated nonlinear processes in these waveguides for the frequency doubling of near infrared light at 1319 nm. After summarizing the technological processes adopted for the fabrication of planar and channel structures in z-cut LN, we report the preliminary experimental results obtained in planar waveguides, along with numerical simulations in both one- and two-dimensional geometries.