Explore the groundbreaking field of biophotonics with “Biophotonics: Optical Science and Engineering for the 21st Century.” This essential read delves into the fascinating world of biophoton emission, the weak photon flux emitted by all living systems, and its profound connection to biological and physiological functions. Discover how these biophotons may act as a crucial information channel, influencing cell reactivity, growth, differentiation, and intercellular communication. This comprehensive book presents the fundamental experimental and theoretical frameworks, addresses technical challenges, and highlights diverse applications across biotechnical, biomedical engineering, medicine, pharmacology, environmental science, and basic science. A must-have for researchers and professionals seeking to understand the future of optical science in biology and medicine, “Biophotonics” fosters vital dialogue between biophoton research and photon technology for advancements in the 21st century.