Book excerpt: This is the first book to investigate the improved performance of optical radiation detectors developed from the ultraviolet to the far-infrared in the past two decades. The development and applications of these improved detectors opened up a new era in radiometric, photometric, colorimetric, and radiation-temperature measurements where earlier blackbody sources and lamps were used with lower performance and in limited application areas. This book will serve to help students, practicing scientists, engineers, technicians, and instrument manufacturers to learn, compare and select the proper detectors for building, using, and calibrating opto-electronic instruments with SI traceability and lowered measurement uncertainty in extended application areas.