The embryonic development of femtoscience stems from advances made in the generation of ultrashort laser pulses. Beginning with mode-locking of glass lasers in the 1960s, the development of dye lasers brought the pulse width down from picoseconds to femtoseconds. The breakthrough in solid state laser pulse generation provided the current reliable table-top laser systems capable of average power of about 1 watt, and peak power density of easily watts per square centimeter, with pulse widths in the range of four to eight femtoseconds. Pulses with peak power density reaching watts per square centimeter have been achieved in laboratory settings and, more recently, pulses of sub-femtosecond duration have been successfully generated. As concepts and methodologies have evolved over the past two decades, the realm of ultrafast science has become vast and exciting and has impacted many areas of chemistry, biology and physics, and other fields such as materials science, electrical engineering, and optical communication. In molecular science the explosive growth of this research is for fundamental reasons. In femtochemistry and femtobiology chemical bonds form and break on the femtosecond time scale, and on this scale of time we can freeze the transition states at configurations never before seen. Even for n- reactive physical changes one is observing the most elementary of molecular processes. On a time scale shorter than the vibrational and rotational periods the ensemble behaves coherently as a single-molecule trajectory.

Keeping abreast of the latest techniques and applications, this new edition of the standard reference and graduate text on laser spectroscopy has been completely revised and expanded. While the general concept is unchanged, the new edition features a broad array of new material, e.g., frequency doubling in external cavities, reliable cw-parametric oscillators, tunable narrow-band UV sources, more sensitive detection techniques, tunable femtosecond and sub-femtosecond lasers (X-ray region and the attosecond range), control of atomic and molecular excitations, frequency combs able to synchronize independent femtosecond lasers, coherent matter waves, and still more applications in chemical analysis, medical diagnostics, and engineering.

The spectra of molecules containing more than one atom are necessarily of single atoms. They are correspondingly much more complex than those richer, not only in the number of spectral lines, but also in qualitatively different phenomena which do not have any counterpart in single atoms. Historically, molecular spectra have revealed much fundamental phy sics, such as the connection between nuclear spin statistics. They have pro vided models of physical systems which have been useful in quite different areas, such as particle physics. Most especially, molecular spectra are of fundamental importance in understanding chemical bonding. They reveal not only bond lengths but also the strength of the bonding potential between atoms. Moreover, these measurements are obtained for electronic excited states, as well as for the ground state, and for unstable short-lived molecules. In recent years, tunable lasers have provided powerful tools for the measurement and analysis of molecular spectra. Even before that, molecules were being used in lasers, most notably in the carbon dioxide laser, which finds many industrial applications.

Bringing together scattered literature from a range of sources, Laser Spectroscopy and ItsApplications clearly elucidates the tools and concepts of this dynamic area, and providesextensive bibliographies for further study.Distinguished experts in their respective fields discuss resonance photoionization, laser absorption,laser-induced breakdown, photodissociation, Raman scattering, remote sensing,and laser-induced fluorescence. The book also incorporates an overview of the semiclassicaltheory of atomic and molecular spectra.Combining background at an intermediate level with an in-depth discussion of specifictechniques, Laser Spectroscopy and Its Applications is essential reading for laser and opticalscientists and engineers; analytical chemists; health physicists; researchers in optical,chemical, pharmaceutical, and metallurgical industries. It will also prove useful for upperlevelundergraduate and graduate students of laser spectroscopy and its applications, andin-house seminars and short courses offered by firms and professional societies.

The book includes all the recent major advances in the field of Laser Spectroscopy. Major results span from the control of matter by electromagnetic fields (trapping and coding) to high precision measurements on simple atomic systems and to quantum optics with single atoms. As an outstanding contribution, the reader will find in the book the first report of the Bose-Einstein condensation achieved by laser-cooling of rubidium atoms. Achievements in the technology of tunable sources, in particular of miniaturized solid state devices, are also reported. Most recent advances in molecular spectroscopy are illustrated with emphasis on 'cooled' spectra, clusters and high accuracy frequency references. Topics such as atomic interferometry and microcavity quantum optics are also covered.

This volume contains the lectures and seminars presented at the NATO Advanced Study Institute on "Applied Laser Spectroscopy" the fourteenth course of the Europhysics School of Quantum Electronics, held under the supervision of the Quantum Electronics Division of the European Physical Society. The Institute was held at Centro "I Cappuccini", San Miniato, Tuscany, Italy, September 3-15,1989. The Europhysics School of Quantum Electronics was started in 1970 with the aim of providing instruction for young researchers and advanced students already engaged in the area of quantum electronics or wishing to switch to this area from a different background. Presently the school is under the direction of Professors F.T. Arecchi and M Inguscio, University of Florence and Prof. H. Walther University of Munich and has the headquarters at the National Institute of Optics (INO), Firenze, Italy. Each time the directors choose a subject of particular interest, alternating fundamental topics with technological ones, and ask colleagues specifically competent in a given area to take the scientific responsibility for that course.