Light people: Professor Ioannis Papakonstantinou

From optical communications and nanophotonics to sustainable cooling and climate-resilient agriculture, Professor Ioannis Papakonstantinou has built a research career around a central question: how can light be controlled and engineered to address real-world challenges? As Professor of Photonics and Nanofabrication at University College London and Head of the Photonic Innovations Lab, his work spans fundamental light-matter interactions, nanostructured and multifunctional surfaces, luminescent solar concentrators, optical communications and passive thermal management. Across these diverse areas, his research combines theoretical modelling, nanofabrication and experimental validation, while maintaining a strong emphasis on translating photonic concepts into scalable technologies (Figs. 1, 2, 3, 4).In this issue of Light People, we are delighted to feature Professor Papakonstantinou and explore the scientific ideas and personal experiences that have shaped his interdisciplinary career. From reimagining luminescent solar concentrators for optical communications and horticulture to developing adaptive materials and passive radiative-cooling technologies, the conversation reveals a research philosophy grounded in fundamental physics but driven by applications in sustainability and society. We also discuss his views on scientific risk, collaboration, research culture, and the role photonics may play in addressing some of the major technological and environmental challenges of the coming decades.