The rapid growth of the use of optoelectronic technology in Information and Communications Technology (ICT) has seen a complementary increase in the performance of such technologies. As a result, optoelectronic technologies have replaced the technology of electronic interconnections. However, the control of manufacturing techniques for optoelectronic systems is more delicate than that of microelectronic technologies. This practical resource, divided into four chapters, examines several methods for determining the reliability of infrared LED devices. The primary interest of this book focuses on methods of extracting fundamental parameters from the electrical and optical characterization of specific zones in components. Failure mechanisms are identified based on measured performance before and after aging tests. Knowledge of failure mechanisms allows formulation of degradation laws, which in turn allow an accurate lifetime distribution for specific devices to be proposed.