This book has grown out of a course that I have taught at the Optical Sciences Center of the University of Arizona over the past five years. The idea has been to introduce graduate students from various backgrounds, either in physics or in one of the engineering disciplines, to the physical principles of magneto-optical (MO) recording. The topics selected for this course were of general interest, since both optics and magnetism are very broad and have many applications in modern science and technology. Each topic was treated in a self-contained and comprehensive manner. The students were first motivated by being told the relevance of a subject to optical data storage, then the subject was developed from basic principles, and examples were given along the way to show its application in quantitative detail. At the end of each chapter homework problems were assigned, so that students could learn certain details that were left out of the lectures or find out new directions in which their newly acquired knowledge could be applied.

The book essentially follows the format of the lectures, albeit with the addition of several chapters whose classroom coverage has usually been inhibited by the finite length of a semester. My primary goal in writing the book is to open the field to graduate students in physical sciences. Most college courses these days are based on single-issue topics that can be covered fairly comprehensively in the course of one or two semesters.