Major advancements in biophotonics have successfully permeated biochemistry and cell/molecular biology as well as numerous preclinical applications. This book presents the fundamentals of optics and biophotonics to newcomers who are interested in this multidisciplinary research field. With contributions from leading experts, the text highlights major current advancements in preclinical diagnostics using optical microscopy and spectroscopy, including multiphoton microscopy, nanoscopy, and endomicroscopy. The book also introduces a number of emerging techniques and toolsets for biophotonics applications, such as nanoplasmonics, microresonators for molecular detection, and subcellular optical nanosurgery.