The study of phenomena that arise when light interacts with matter and the wave features of light constitute the subject of wave optics. This book assists the learners in applying the acquired theoretical knowledge to the real-life applications. It is written in a simple language, the presentation is lucid, and detailed mathematical steps have been worked out. The book focuses on wave nature of light, wave phenomena and modern optics. This book is intended for the undergraduate students of physics—both honours and general courses—it will also be useful to those appearing in competitive examinations.