Influence of Zn/In codoping on the optical properties of lithium niobate

The influence of a combined doping with Zn and In on the optical properties of lithium niobate is studied. While each of these dopants is known to improve the material's nonlinear optical properties, it is an open question whether further improvements, especially of the nonlinear optical features, can be achieved by a suitable combination of dopants. Our measurements show that lithium niobate imposes certain limits which cannot be overcome. This can be described by a simple model which is based on the defect structure of lithium niobate.