This book titled "Optics" is a comprehensive guide designed primarily for undergraduate students pursuing physics and engineering courses. Among the three fundamental branches of optics—Geometrical Optics, Physical (Wave) Optics, and Quantum Optics—this focuses deeply on Physical (Wave) Optics. Beginning with the basic nature of light, the text guides readers through key topics including: • Interference and the principle of superposition • Young’s double-slit experiment • Coherence and coherent sources • Diffraction and resolving power • Polarization of light • LASER theory and types of lasers • Optical instruments and applications • Holography Each chapter is structured with clear objectives, theoretical background, mathematical formulation, and relevant applications. Special attention has been given to the pedagogical needs of students, with definitions, key points, solved numerical problems, illustrations to facilitate learning and more than 400 multiple choice questions. The book is not only suited for exam preparation but also for developing a lasting understanding of optics as a discipline.