As we enter the nineties, there is worldwide awareness that the future of all mankind is inexorably linked by the world we share, and its response to man's activities. Lasers and the optical sciences have brought powerful tools to measure and understand our environment. LIDAR (laser radar) and laser fluorescence allow us to measure atmospheric and oceanic pollutants, as well as industrial emissions, from many kilometers distance. And a variety of sensitive laser-based spectroscopic techniques permit the accurate analysis of heavy metals and other trace elements in the environment. In September 1989, an international group of scientists me.t in Erice, Sicily, for the 14th Course of the International School of Quant~ Electronics. This Course was devoted to "Optoelectronics for Envi~onmental Science", and was ably directed by Prof. V. S. Letokhov of the USSR Institute of Spectroscopy and Prof. A. M. Scheggi of the C.N.R. Electro­ magnetic Waves Institute, Florence, Italy. This book gives the proceedings of that conference, which covered not only basic tutorial papers but also reports on the latest research results. The first half of this volume describes the techniques used for direct "In-Situ Measurements" of the environment. In "Techniques and Programs", four chapters and one extended abstract give tutorial discussions of the most important remote sensing techniques: LIDAR, laser fluorescence, and optical fiber sensors, plus a description of the Italian program in this area.

In-Situ Measurements.- Techniques and Programs.- Atmospheric pollution monitoring using laser lidars.- Laser fluorescence spectroscopy in environmental monitoring.- Optical fiber sensors for the environment.- Fibre optic chemical and biochemical sensors for environmental monitoring.- Realizations and programs of ENEA in the field of optoelectronics.- Atmospheric Ozone.- The Italian program in Antarctica, related to the ozone hole problem and the experimental cloud lidar pilot study.- Differential absorption lidar detection of ozone in the troposphere and lower stratosphere.- Determination of atmospheric ozone profiles at 68N and 79N with a daylight lidar instrument.- Other Atmospheric Sensing.- Laser atmospheric wind velocity measurements.- Differential optical absorption spectroscopy (DOAS) for the continuous monitoring of atmospheric trace constituents at a high alpine station.- Photoacoustic NH3 monitoring with waveguide CO2 lasers.- Oceanographic Measurements.- Fluorescence lidars in environmental remote sensing.- Hydrographie applications of airborne laser spectroscopy.- Laboratory Analytical Techniques.- Heavy Metal Analysis.- Quantitative detection of strontium-90 and strontium-89 in environmental samples by laser mass spectroscopy.- Laser ultrasensitive photoionization detection of rare elements in geochemistry, oceanology and study of geological catastrophes.- Determination of toxic metals in environmental objects by laser excited atomic fluorescence spectrometry.- Trace analysis of plutonium and technetium by resonance ionization mass spectrometry using an atomic beam and a laser ion source.- Other Trace Elements.- Tunable diode laser spectroscopy for the reconstruction of atmospheric CO2-concentrâtions of the past 50,000 years.- Resonance ionizationspectroscopy for dating very old groundwater.- Techniques and Instrumentation.- Laser ablation for microanalysis.- The fundamentals of trace analysis using resonant ionization mass spectroscopy.- Production and detection of selectively laser ionized species.- Principles of complex interferometry.- Adaptive optics in the far IR and submillimeter ranges.