Metal hydrides for smart window and sensor applications

The hydrogenation of metals often leads to changes in optical properties in the visible range. This allows for fundamental studies of the hydrogenation process, as well as the exploration of various applications using these optical effects. Here, we focus on recent developments in metal hydride-based optical fiber and plasmonic sensors and smart windows. Both applications benefit from the existence of a reflective metallic state, which is lost on hydrogenation and allows for large reversible optical changes. In this article, we review the status of both technologies and their prospects for applications.