This volume contains the proceedings of a two-week NATO A.S.I. on Integrated Optics: Physics and Applications, held from August 17 to August 30, 1981 in Erice, Italy. This is the 8th annual Course of the "International School of Quantum Electronics" presented under the auspices of the "E. Majorana" Centre for Scientific Culture. The subject was chosen in order to satisfy the demand for a course on integrated optics which is relevant to the expanding use of fiber optics for communication and signal processing. Integrated Optics, encompassing all of the optical waveguide circuits which are the optical analog of integrated circuits, is finding its way into a variety of applications involving communi cations, high speed signal-processing, and sensors of many kinds. However, because the technology is still changing very rapidly, the development of these exciting applications relies heavily upon the physics of the integrated optical circuits themselves and the pro cessing techniques used to fabricate them. This NATO A.S.I. provided not only a thorough tutorial treatment of the field, but also through panel discussions and additional lectures treated topics at the forefront of present work. Therefore the character of the Course was a blend of current research and tutorial reviews. "The Physics and Applications of Integrated Optics" could hardly be a more appropriate title to be chosen for this volume. Many of the worlds'' acknowledged leaders in the field have been brought together to review and speculate on the accomplishments of integrated optics.