Second-harmonic generation in potassium niobate waveguides

We report on our progress in the formation of waveguides in potassium niobate (KNbO₃) using techniques such as ion implantation and ion sputtering. Different methods for the structuring of channel waveguides are presented, and their advantages and disadvantages are discussed in terms of their optical and nonlinear optical properties. The excellent power-handling capability of KNbO₃ waveguides is compared to other waveguide materials, and we highlight the influence of postimplantation annealing and repoling on the waveguide attenuation and the nonlinear optical coefficient. We also review recent results on second-harmonic generation in KNbO₃ waveguides focusing on blue light generation