Major evolutions in optical communication systems are now driven by short-range systems, such as in e.g. data center networks, where massive amounts of information need to be transmitted reliably, with low latency, and at a fraction of the cost of legacy core optical transmission systems. Optical links are also being considered in future network-on-chip architectures. Meanwhile, the need for enhanced throughputs in long-distance communication systems has triggered investigations of increasingly complex modulation formats at high bit-rates (nowadays > 100 Gbit/s) as well as the exploration of the last remaining multiplexing degree of freedom, i.e. space, under the form of mode-division multiplexing. Visible light communication and microwave photonics have also become hot topics of research over the past few years. Integration is of paramount importance for all those applications in order to reach the best compromise between throughput, energy consumption, footprint and cost. Typical devices of interest include optical transmitters and receivers, nonlinear waveguides and micro- or nano-resonators for the implementation of all-optical signal processing functionalities, as well as devices allowing spatial light shaping and manipulation. Experience has shown that integrated devices and technologies initially developed for communication applications are also instrumental for other photonic technologies, including sensors, lidars, biomedical optics, etc. The PHOTONET IRN covers the entire value chain of optical communications, from the design and fabrication of advanced integrated structures to proof-of-concept subsystem demonstrations. Partners WNLO, ZJU, FDU, C2N, ICube and Foton will contribute to novel devices design, fabrication and system testing. Natural interactions also exist with the research axis on “Emerging materials and concepts in photonics” and associated partners.