Optoelectronics is the branch of science which deals with the study and application of various electronic systems and devices which are capable of sourcing, detecting and controlling light. This encompasses visible as well as invisible form of light such as infrared rays, ultraviolet rays and gamma rays. Optoelectronic devices are transducers which possess either optical-to-electrical or electrical-to-optical nature. Such devices are based on the quantum mechanical effects of light on different electronic materials. Some of the important aspects of the discipline of optoelectronics are photovoltaic effect, photoconductivity, stimulated emission, radiative recombination and photoemissivity. Optical fibers are one of the most prominent applications of optoelectronics. This book presents the complex subject of optoelectronics in the most comprehensible and easy to understand language. The topics included herein on optoelectronics are of utmost significance and bound to provide incredible insights to readers. This book will serve as a valuable source of reference for those interested in this field.