In a field that has significantly matured over time, it is vital for engineers to have access to comprehensive, clear knowledge on selecting, operating, and testing of infrared devices. This book presents concepts in a user-friendly manner to explain the selection and usage of single element detectors, very small Focal Plane Arrays (FPA) and large FPAs for imaging. This book is the perfect all-inclusive introduction to the infrared field for newcomers and a refresher for experienced engineers.