This book presents peer-reviewed and selected papers from the 2025 European Conference on Integrated Optics (ECIO), held on June 10–12, 2025, and organized by Cardiff University, UK, in collaboration with University of York, UK. In the 25th edition of this conference, internationally recognized experts share their latest research and showcase their products and services in the field of integrated optics, optoelectronics, and nano-photonics. The conference focuses on leading-edge research and its broad application scope ranges from tele/datacom, optical interconnects, and (bio) optical sensing to more disruptive areas such as quantum computing and programmable photonics.

Professor Smowton Peter obtained his degree in Physics in 1987 and a Ph.D. in Electronics & Electrical Engineering in 1991 from Cardiff University. He has carried out research in the physics of semiconductor materials and devices and particularly in those properties relevant for the integration of different materials and different functions for most of his career. He is currently the director of the EPSRC Compound Semiconductor Manufacturing Hub and the EPSRC Centre for Doctoral Training in Compound Semiconductor Manufacturing, both of which focus on research into sustainability and the manufacturing processes for technology critical materials and devices. Peter is the managing director of the Institute of Compound Semiconductors, which is a University translational research and small-scale manufacturing facility for the fabrication of Compound Semiconductor devices and integrated systems.

Prof Thomas Krauss obtained his Diplom-Ingenieur degree in Optical Engineering from Cologne, Germany, in 1989 and a Ph.D. in Electronics & Electrical Engineering from the University of Glasgow, UK, in 1992. He pioneered the development of photonic crystals in semiconductor waveguides supported by the SERC and the Royal Society of the UK, before being appointed to a personal Chair at the University of St Andrews, UK, in 2000. In 2012, he took up his current position of Chair of Photonics at the University of York, UK. More recently, his work has focused on biological applications by further developing the guided mode resonance phenomenon, where he has shown that it is particularly suited to the high performance-low cost paradigm which is essential for practical sensing and healthcare applications, which also led him to found a spin-out company. His 400 peer-reviewed publications have been cited 36k times which has led to an h-factor of 97.