Since the book was first published in 1991, the field of surface nonlinear optics has grown substantially to the point where an exposition of the principles of this field will prove useful to many. Thus, in this second edition, Chapter 8 addresses this area. Also, optical probes of magnetism of very thin films and multilayers are now widely used, and magneto-optic devices of increasing sophistication have appeared. Chapter 9 is thus devoted to magneto-optics, and associated nonlinear phenomena. The earlier chapter on "Chaos" appears as Chapter 10. The philosophy which underlies the first edition was also employed in the writing of the two new chapters. Irvine, CA D.L.Mills March 1998 Preface to the First Edition One intriguing aspect of physics is its dynamic and rapidly evolving nature; exciting new fields can become moribund within relatively few years, only to revive and grow again in a dramatic and explosive manner in response to new developments.

The text develops the basic principles that underlie nonlinear optical phenomena in matter, in an approach oriented to the general reader or student with a background in classical electromagnetic theory. It begins with a discussion of linear wave propagation in dispersive media, moves into weak nonlinearities which can be discussed in a pertuberative manner, then examines strong nonlinear effects (solitons, chaos). The emphasis is on the macroscopic description on nonlinear phenomena, within a semi-classical framework. The text is aimed at the student or researcher who is not a specialist in optics, and who wishes to acquire an introduction to the principal concepts as a precursor to the consultation of the specialized literature.