Recent developments in rare-earth doped materials for optoelectronics

Rare-earth doped materials are of crucial importance to optoelectronics, and are widely deployed in fibre amplifiers and solid-state lasers. This article summarises the present state of the art in this rapidly growing field. Recent developments in the areas of rare-earth doped semiconductors and insulators are discussed and new classes of materials that open up new possibilities for extended functionality and greater optoelectronic integration are described. Nanostructured materials and wide bandgap semiconductors are of particular interest, though recent developments in more traditional material systems are highlighted. Emphasis is placed on erbium-doped materials, as these are of the greatest importance for telecommunications applications, but a range of other rare-earth ions are also discussed.