Optics is a textbook written for undergraduate students of Indian Universities, keeping in view the recent developments in optics following invention of lasers. The salient features of the book are four self-contained chapters on Lasers, Holography, Fiber Optics,and Non-Linear Optics at the level of understanding of undergraduate students. Besides, there are standard topics such as Flay Optics, Interference, Diffraction, and Polarization. Even here, the distinctive features are the use of matrix method in ray optics and in description of polarization states of light. Interference due to an extended source is discussed in relevant details to bring out the concept of spatial coherence. There are brief supplements on Kirchhoff’s theory of diffraction and the theory of partial coherence.