Research and Facilities

Research activities of the IQO group cover a wide scope ranging from fabrication of micro-structured devices via the realization of complex quantum optical experiments up to the theoretical analysis of quantum optical systems and their implementation for quantum information processing.

The research areas might be grouped into three categories: "Technology", "Devices" and "Quantum-Networks". "Technology" comprises the fabrication of integrated optical devices and circuits in LiNbO3 and KTP. This includes all necessary process steps, which need to be continuously optimized to meet the challenging demands required for quantum optical experiments. In the area "Devices" we develop novel integrated optical structures and devices like for instance (entangled) photon pair sources. Moreover, research is directed towards the development of monolithically integrated circuits, which jointly combine several optical elements with different functionality on a single optical "chip". Research in "Quantum Networks" is targeted on the development of novel practical concepts in quantum information processing and quantum communication as well as on fundamental research experiments on ultrashort pulse quantum optics. In particular, we focus on the study of correlated, multi-dimensional systems with several coupled channels and on the "engineering" of complex quantum states with strictly controllable properties.

Integrated optical devices and circuits in lithium niobate and KTP are the platform many of our quantum optical experiments are built on. Developing and continuously optimizing the respective technological steps allows us to specifically tailor the devices' linear and nonlinear optical properties to our requirements. Read more on...

Fabrication of Integrated Devices


Future development of quantum communication and information processing (QCIP) will strongly rely on the development of miniaturized and reliable optical components. In our group we approach this goal by harnessing the potential of integrated optics. We develop integrated optical devices and circuits specifically designed for single photon (pair) generation, quantum state manipulation and storage.

Current research activities are targeting the development of:


Research in quantum networking is addressing the development of applicable concepts in quantum information processing and quantum computing. The main research activities are on ultrashort pulse quantum optics and its application, quantum simulation and quantum walks, generation  of specifically engineered (higher-dimensional) quantum states, and quantum state and process tomography using photon number resolved detection. A further new activity is on integrated continuous variable quantum optics.


The technology labs of the group are within excellent clean-room facilities (up to class 100 for most critical processing). All equipment required for the fabrication of integrated devices in LiNbO3 and KTP is available. This includes facilities for lithography, diffusion, dry and wet etching, period poling, .... Moreover, advanced custom designed optical coatings on mirror blanks or waveguide end-faces can be deposited with our with our ion-assisted evaporation machine.  

The group is also well equipped with several optics labs for the characterization of waveguide devices and to perform…


scientific collaborations …

Our research activities are performed within joint cooperations with various international partners.