This book reviews the progress on interband and intersubband transitions in semiconductors, including III-V, IV and II-VI materials and quantum structures. Advances in the development of light sources, detectors, modulators, and electronic materials and devices are also explored. Brought to maturity, such devices will likely see widespread use in applications as diverse as infrared imaging, chemical and biological sensing, surveillance, short-links, space-based applications, solar cells, high-bandwidth communications, and many others. Topics include: infrared materials and devices; quantum dot structures and devices; progress in semiconductor materials - quantum dots, growth and magnetism; terahertz materials and devices; nitride materials for devices; nanostructured semiconductors and novel materials and devices; progress in semiconductors - dielectrics, silicon-, carbon- and nanomaterials; zinc oxide materials and devices including alloys; progress in semiconductor materials - ZnO and dilute nitrides; dilute nitride and bismide semiconductors; and advanced dielectrics and Si-based materials.