Proceedings of the 22nd Course of the International School of Quantum Electronics, held 27 November--2 December 1997, in Erice, Italy. In recent years, fiber optical sensors and optical microsystems have assumed a significant role in sensing and measurement of many kinds. These optical techniques are utilised in a wide range of fields, including biomedicine, environmental sensing, mechanical and industrial measurement, and art preservation. This volume, an up-to-date survey of optical sensors and optical microsystems, aims at combining a tutorial foundation with analysis of current research in this area, and an extensive coverage of both technology and applications.