This textbook provides a sound foundation in physical optics by covering key concepts in a rigorous but accessible manner. Propagation of electromagnetic waves is examined from multiple perspectives, with explanation of which viewpoints and methods are best suited to different situations. After an introduction to the theory of electromagnetism, reflection, refraction, and dispersion, topics such as geometrical optics, interference, diffraction, coherence, laser beams, polarization, crystallography, and anisotropy are closely examined. Optical elements, including lenses, mirrors, prisms, classical and Fabry-Perot interferometers, resonant cavities, multilayer dielectric structures, interference and spatial filters, diffraction gratings, polarizers, and birefringent plates, are treated in depth. The coverage also encompasses such seldom-covered topics as modeling of general astigmatism via 4x4 matrices, FFT-based numerical methods, and bianisotropy, with a relativistic treatment of optical activity and the Faraday and Fresnel-Fizeau effects. Finally, the history of optics is discussed.