Optical science, the science that studies the nature of light, can be approached from several different angles. In this third edition of a successful and well-established text, the author focuses on physical and geometrical optics. The text is based largely on Fourier analysis and shows how this method can be used to describe wave propagation and diffraction and their applications to imaging, microscopy, X-ray crystallography, radio-astronomy, and communication. Several new sections have been added, including discussions of super-resolved imaging (near field and confocal microscopy), phase-retrieval in optical and X-ray diffraction, phase-conjugate imaging, astronomical speckle masking, and squeezed-light interferometry. Throughout, the subject matter is developed by a combination of unsophisticated mathematics and physical intuition. The very broad range of subjects treated, together with the inclusion of many problems and over 300 diagrams and photographs, will make the book of great use to undergraduate and graduate students of physics, and to anyone working in the field of optical science.