Chemical Patterning Technique for Periodic Poling of KTP Waveguides

Periodically-poled waveguides have become important for nonlinear frequency conversion because of the advantages inherent in quasi-phasematching and in the guided-wave nature of the interaction.1 A variety of techniques have been used to produce periodically-poled waveguides; one that has received particular attention is electric field poling, in which an electric field large enough to invert ferroelectric domains is applied to a periodic electrode.2,3 This approach to domain inversion suffers from difficulties inherent in controlling the width of the inverted domain, which is necessary in order to optimize the second harmonic output power.