This book has grown out of a need for a beginning graduate level text which emphasizes the unifying concepts of the field of guided wave optics. Over the past twenty years, progress in this field has been so rapid, and therefore so helter-skelter, that it is hard, even for the fully involved practitioner no less the aspiring student, to see the unifying concepts. As will be discussed more fully below, there are at present quite a number of texts in the guided wave area. These texts vary in nature from the popular treatise to the voluminous scholarly work. I know of none, however, that treats the waveguide, semi­ conductor laser, fiber and fiber component, and integrated optic component all on equal footing using the forms of Maxwell's equations in polarizable media and coupled forms of Maxwell's equations as unifying tools. This book emphasizes basic concepts, yet is quantitative in nature and contains numerous applications. The book is designed to be used by the beginning graduate student or the professional who needs to review or catch up on the basics. Here at the University of Colorado, this text is generally used for a follow-up course to one in Physical Optics. The Physical Optics text employed, also written by the present author, primarily includes material which should be familiar to students with a strong background in optics or practitioners of guided waves.