This book covers optical chemical sensing by means of optical waveguides, from the fundamentals to the most recent applications. The book includes a historical review of the development of these sensors, from the earliest laboratory prototypes to the first commercial instrumentations. The book reprints a lecture by the Nobel Laureate Charles Townes on the birth of maser and laser, which lucidly illustrates the development of new science and new technology.

Optical beams are electromagnetic waves that remain essentially concentrated around a mean axis upon free propagation or that are guided by suitable structures. The study of these beams has existed long ago and since then this field has been a focus of active investigation. However, in recent years, the interest on optical beams has further increased, due to the availability of many types of laser sources, characterized by very different properties, as far as their polarization, coherence, spectral content, and spatial distribution are concerned.This book contains lectures presented in the 35th International School of Quantum Electronics at the Ettore Majorana Centre in Erice, Sicily. It gives the latest coverage on the development and advance in “Free and Guided Optical Beams”. The purpose of these lectures was to give an updated overview, as complete as possible, on topics concerning the propagation of light beams in free space, in materials, and in guiding structures, and to provide the tools needed to its study, both from the theoretical and the application point of view.The lectures presented here are written in extended review-like format. Both introductory fundamental topics and recent research results are reviewed, making this an indispensible book for novice as well as experts in this field.The proceedings have been selected for coverage in:• Index to Scientific & Technical Proceedings® (ISTP® / ISI Proceedings)• Index to Scientific & Technical Proceedings (ISTP CDROM version / ISI Proceedings)• CC Proceedings — Engineering & Physical Sciences

The main fields represented at this school are: laser physics, gas lasers, laser applications in materials processing and microelectronics, non-linear and fiber optics, remote laser atmospheric sounding and laser spectroscopy.

First multi-year cumulation covers six years: 1965-70.

Proceedings of the 20th Course of the International School of Quantum Electronics held in Erice, Italy, November 14-24, 1996

The volume contains the proceedings of the 7th Course on Physics and Technology of Free Electron Lasers of the International School of Quantum Electronics, which was held in Erice (Italy) from 17 to 29 August 1980, under the auspices of the "Ettore Majorana" Centre for Scientific Culture. The level of this Course was much closer to a workshop than to a school, and "Advances in Free Electron Lasers" might have been an appropriate title. Many of the world's leading scientists in the field (among them, the inventor of FEL, J. M. J. Madey) were brought together to review the accomplishments of FEL experiments, as well various trends in FEL theory. In editing this material we did not modify the original manu scripts except to assist in uniformity of style. The papers. are presented without reference to the chronology of the Course but in the following topical arrangement: A. "Fundamentals of free electron lasers," a group of tutorial papers; B. "Free electron lasers operating in the Compton regime," where theories and experiments of FELs based on Compton scattering are reviewed; C. "Free electron lasers operating in the Raman regime," a dis cussion of FELs based on Raman scattering; D. "Optical klystrons," where the possibility of this class of FEL is discussed from a theoretical viewpoint; E.