This book is motivated by the very favorable reception given to the previous editions as well as by the considerable range of new developments in the laser ?eld since the publication of the third edition in 1989. These new developmentsinclude, among others, Quantum-Well and Multiple-Quantum Well lasers, diode-pumpedsolid-state lasers, new concepts for both stable and unstable resonators, femtosecond lasers, ultra-high-brightness lasers etc. The basic aim of the book has remained the same, namely to providea broad and uni?ed description of laser behavior at the simplest level which is compatible with a correct physical understanding. The book is thereforeintendedas a text-bookfor a senior-levelor ?rst-year graduatecourse and/or as a reference book. This edition corrects several errors introduced in the previous edition. The most relevant additions or changes to since the third edition can be summarized as follows: 1. A much-more detailed description of Ampli?ed Spontaneous Emission has been given [Chapt. 2] and a novel simpli?ed treatment of this phenomenon both for homogeneousor inhomogeneouslines has been introduced [Appendix C]. 2. A major fraction of a chapter [Chapt. 3] is dedicated to the interaction of radiation with semiconductor media, either in a bulk form or in a quantum-con?ned structure (quantum-well, quantum-wire and quantum dot). 3. A moderntheory of stable and unstable resonatorsis introduced,where a more ext- sive use is made of the ABCD matrix formalism and where the most recent topics of dynamically stable resonators as well as unstable resonators, with mirrors having Gaussian or super-Gaussian transverse re?ectivity pro?les, are considered [Chapt. 5].

Introductory Concepts.- Interaction of Radiation with Atoms and Ions.- Energy Levels, Radiative, and Nonradiative Transitions in Molecules and Semiconductors.- Ray and Wave Propagation Through Optical Media.- Passive Optical Resonators.- Pumping Processes.- Continuous Wave Laser Behavior.- Transient Laser Behavior.- Solid-State, Dye, and Semiconductor Lasers.- Gas, Chemical, Free Electron, and X-Ray Lasers.- Properties of Laser Beams.- Laser Beam Transformation: Propagation, Amplification, Frequency Conversion, Pulse Compression, and Pulse Expansion.- Appendixes: Semiclassic Treatment of the Interaction of Radiation and Matter.- Line Shape Calculation for Collision Broadening.- Simplified Treatment of Amplified Spontaneous Emission.- Calculating Radiative Transition Rates of Molecular Transitions.- Space-Dependent Rate Equations.- Mode-Locking Theory: Homogeneous Line.- Propagation of a Laser Through a Dispersive Medium or a Gain Medium.- Higher Order Coherence.- Physical Constants and Useful Conversion Factors.- Answers to Selected Problems.- Index.

This volume is a collection of papers presented at the Ninth International Symposium on "Ultrafast Processes in Spectroscopy" (UPS '95) held at the International Centre for Theo retical Physics (ICTP), Trieste (Italy), October 30 -November 3, 1995. These meetings have become recognized as the major forum in Europe for discussion of new work in this rapidly moving field. The UPS'95 Conference in Trieste brought together a multidisciplinary group of researchers sharing common interests in the generation of ultrashort optical pulses and their application to studies of ultrafast phenomena in physics, chemistry, material science, electronics, and biology. It was attended by approximately 250 participants from 20 countries and the five-day program comprises more than 200 papers. The progress of both technology and applications in the field of ultrafast processes during these last years is truly remarkable. The advent of all solid state femtosecond lasers and the extension of laser wavelengths by frequency conversion techniques provide a large variety of high-performance light sources for ultrashort pulses. With these sources ultrafast phenomena in physical, chemical and biological systems and in electronic de vi(:es are now studied extensively. Ultrafast technology is becoming one of the basic and common tools presently entering a wide variety of scientific fields not only for basic re search but also for promoting new applications in various areas. We feel that these pro ceedings vividly reflect the present status of the field.

This book presents the first comprehensive collection of solved problems in laser physics covering both fundamental and applied aspects of laser science and technology. The framework of the book, including structuring of topics and notations, closely follows that adopted in the Principles of Laser book by Professor O. Svelto. The collection of problems presented in this book appears therefore a natural complement to Svelto's textbook for testing and developing the skills acquired in the reading of the theory; however, it may also be a useful support to any general textbook on laser physics, wherein problems are usually not solved in detail. We remark that this is, to our knowledge, the first book to provide a complete and satisfactory set of solved problems in such a highly developing field of science and technology. The problems fall mainly into three distinct categories: (i) numerical/applied problems, which help the reader to become confident and familiar with the basic concepts and methods of laser physics, and to acquire a feeling for numerical parameters entering in real-world laser systems; (ii) complementary problems, that present in detail demonstrations of some analytical parts not given in the textbook; and (iii) advanced problems, aimed either to provide a deeper understanding of the subject or to cover more recent developments in the field. Audience: This book is primarily intended for undergraduate and graduate students in physics, engineering, and chemistry. However, it may also be a useful tool for industrial professionals working in the field of laser technologies and laser applications, as well as for researchers interested in basic aspects of real-world lasers andrelated fields.

Ultrashort Pulse Lasers. All Solid-State Tunable Ultrafast Laser Oscillators and Amplifiers for Real-World Applications Including Medical Imaging; N.P. Barry, et al. Ultrafast Spectroscopy of Atoms and Molecules. Vibrational Coherence in Photoisomerization Reaction of Cis-stilbene in Solution; D.K. Palit, et al. Ultrafast Non-Linear Optical Phenomena. Ultrafast Temporal Dynamics in an Optical Microscopic Cavity; P. Mataloni, et al. Ultrafast Spectroscopy of Semiconductors. Optical Cross-talk between Quantum Wells; D. Weber, et al. Generation and Applications of Intense Ultrashort Pulse. High-Brightness Excimer Lasers; S. Szatmari, et al. Frequency Conversion. Femtosecond Pulse Compression by Sum-Frequency Generation in BBO; A. Varanavicius, et al. Ultrafast Non-Linear Optics in Organics. Femtosecond Dynamics in Conjugated Polymers; T. Kobayashi. Applications of Ultrafast Lasers in Medicine and Ultrafast Processes in Biophysics. Imaging Through Diffusing Media with Time Resolved Transmittance; R. Cubeddu, et al. Ultrafast Spectroscopy of Metals, Insulators and Confined Systems. New Ultrafast Measurement Techniques. Superconductors and the Terahertz Spectroscopy. Ultrafast Optoelectronics. 139 Additional Articles. Index.