Because integrated optics and optoelectronics technology have been devel­ oping very rapidly during the past few years, significant advances have been made since the first edition of this book was published. Furthermore, interest in the book itself has been strong, leading to a demand for a new, updated version of the text. This has motivated us to issue the present revised pa­ perback edition, whose lower price will make it more easily accessible to researchers in the area and to interested graduate students, in particular. The present edition is essentially similar to the original hardcover book, except that a new chapter (Chap. 7) has been added, which briefly reviews the recent advances in the area and provides new references. Typographical errors spotted in the original edition have also been corrected. Although great care has been exercised, some errors may still occur in the text and other improvements could be introduced in a possible future edition. The volume editor would therefore appreciate any comments from readers, who are urged to communicate their suggestions directly to him.