Book excerpt: A comprehensive treatment of the fundamentals of optical detection theory. Laser system applications are becoming more numerous, particularly in the fields of communications and remote sensing. This book addresses the theoretical aspects of optical detection and associated phenomenologies, describing the fundamental optical, statistical, and mathematical principles of the modern laser system. The book is especially valuable for its extensive treatment of direct detection statistics, which has no analog in radar detection theory and which has never before been compiled in a cohesive manner in a single book.