Integrated optical devices and circuits in lithium niobate and KTP are the platform many of our quantum optical experiments are built on. The idea of Integrated Quantum Optics using nonlinear optical waveguide substrates is to combine active optical elements such as frequency converters, electro- and acousto-optical devices with passive elements, like directional couplers, tapers, beam splitters and junctions. While a single linear coupler or a nonlinear waveguide are sufficient for some applications, more sophisticated device designs will monolithically integrate a number of such functionalities within a single optical waveguide chip, a so called integrated optical circuit (IOC).
A successful development of such IOCs requires elaborated fabrication technologies. Thus, one of our research activities is the development and continuous optimization of the respective technological steps for the fabrication of integrated waveguide devices fulfilling the high demands from quantum optics.