Recent advances in the growth of novel-engineered structures such as sophisticated semiconductor superlattices and heterostructures, as well as new nonlinear optical materials, have opened exciting possibilities for infrared sources, detectors, modulators and novel devices. Brought to maturity, such discrete devices could likely see widespread use in applications as diverse as infrared imaging, chemical sensing, surveillance, short-link and high-bandwidth communications. This book published by MRS, brings together a group of internationally recognized experts in the field to discuss recent progress in materials, physics, processing and device design and performance. Developments in materials for cooled and uncooled infrared systems based on pyroelectric, micro-bolometric, photovoltaic and photoconductive detectors are emphasized. Progress in compact infrared sources is also highlighted. Topics include: antimonide-related materials - growth, characterization and analysis; antimonide-related devices; innovative infrared devices; infrared detectors; growth and doping of II-VI materials; interdiffusion in quantum-well materials and infrared applications; nonlinear optical and OPO materials and related contributions.