The main research topic of the Nano-Optics Group at the Humboldt University of Berlin (UBER) is light-matter interaction on the nanoscale. The focus is on the realization and investigation of quantum optical model-systems with almost ideal parameter control. In this way quantum interaction on the meso-scale can be revealed. These model systems may also be regarded as building blocks for a future integrated quantum technology. UBER participates in technical workpackage WP3 based on its expertise in: generation and characterisation of single- and few-photon states; design and implementation of photon-pair sources with specific optical properties; and in quantum information tasks with single photons, such as quantum algorithms, multiplexed single-photon QKD, and photon conversion.