Periodically poled LiNbO3 for nonlinear optical applications - fabrication and characterisation

Periodic poling of z-cut Lithium Niobate is reliably achieved in up to 1 mm thick crystals. Domain patterns with sharp domain walls over the entire volume of the crystal are obtained. Proton exchanged strip waveguides have been added to the periodically poled Lithium Niobate crystals in order to increase conversion efficiency. Third-order single-pass continuous wave second harmonic generation at 430 nm is demonstrated and a normalised conversion efficiency of up to 2%/Wcm has been obtained.