Fundamentals of Optical Metrology is a comprehensive exploration of principles, techniques, and applications of optical measurement. Emphasizing precision and accuracy, the text highlights calibration strategies, error compensation, and uncertainty analysis, equipping readers with skills to conduct robust measurements across diverse industrial and research contexts. The book is enriched with illustrative examples, real-world case studies, and references connecting theory to practical challenges fostering both conceptual and applied competence. Content covers interferometry, spectroscopy, imaging systems, and laser-based measurement techniques. Readers examine dimensional metrology, surface profiling, optical testing, and quality control procedures. Key topics include optical instrumentation design, signal processing, and measurement standards. The text addresses emerging technologies including digital holography, optical coherence tomography, and nanoscale metrology. Through systematic presentation combining theoretical foundations with practical implementation, the material develops comprehensive optical metrology capabilities. This essential resource serves metrology professionals, optical engineers, quality control specialists, and graduate students in photonics and precision engineering. The book provides both fundamental principles and advanced techniques for modern optical measurement systems.