This volwne contains the Proceedings of a two-week summer conference titled "Advances in Integrated Optics" held June 1-9, 1993, in Erice, Sicily. This was the 18th annual course organized by the International School of Quantum Electronics, under the auspices of the "Ettore Majorana" Centre for Scientific Culture. The term Integrated Optics signifies guided-wave optical circuits consisting of two or more devices on a single substrate. Since its inception in the late 1960's, Integrated Optics has evolved from a specialized research topic into a broad field of work, ranging from basic research through commercial applications. Today many devices are available on market while a big effort is devolved to research on integrated nonlinear optical devices. This conference was organized to provide a comprehensive survey of the frontiers of this technology, including fundamental concepts, nonlinear optical materials, devices both in the linear and nonlinear regimes, and selected applications. These Proceedings update and augment the material contained in a previous ISQE volume, "Integrated Optics: Physics and Applications", S. Martellucci and A. N. Chester, Eds. , NATO ASI Series B, Vol. 91 (Plenum, 1983). For some closely related technology, the reader many also wish to consult the ISQE volumes: "Optical Fiber Sensors", A. N. Chester, S. Martellucci and A. M. Scheggi, Eds. , NATO ASI Series E, Vol. 132 (Nijhoff, 1987) ; and, "Nonlinear Optics and Optical Computing", S. Martellucci and A. N. Chester, Eds. , E. Majorana Int'! Science Series, Vol. 49 (plenum, 1990).