This book grew out of a graduate course given in the Physics Department of the City College of New York for the first time during the 1976-1977 academic year and a series of lectures given at the Catholic University of Louvain, at Louvain-la-Neuve, Belgium during the Spring and Summer of 1977. I am indebted to Professor F. Brouillard and the DYMO group at that institution for the stimulation and hospitality provided during that period. In both cases, the lectures were at a level that assumed only a knowledge of elementary quantum mechanics of a typical first-year grad uate course. I have tried to continue that level of discussion in this book and to make it self-contained for any discussions that go beyond that level. In some sections of the book, the problems dealt with are too complicated to provide the entire description here. In that case, references to the original work are given.

Inhalt
1 Basic Ideas.- 1.1. Introduction.- 1.2. Transition to a Classical Description of the Laser.- 1.3. Dipole Approximation, Center-of-Mass Transformation, Ponderomotive Potential.- 1.4. Gauge Transformations.- 1.5. Transitions and Gauge Invariance.- 1.6. Laser Statistics, Fluctuations, and Multimode Operation.- Notes and References.- 2 States in a Weak-Near-Resonant Laser.- 2.1. Introduction.- 2.2. Two-State Rotating Wave Approximation.- 2.3. Estimation of Errors.- 2.4. Adiabatic Time Dependence.- 2.5. Excitation.- 2.6. Coherent Trapping in the Three-State Problem.- Notes and References.- 3 States of an Atom in a Laser.- 3.1. Introduction.- 3.2. Definition of the States.- 3.3. Weak Nonresonant Field ExampleDynamic Stark Effect.- 3.4. Ultraintense Laser Field Example.- 3.5. Weak Resonant Field Example.- 3.6. Very High Frequency Example.- 3.7. The Two-State Atom in a Low-Frequency Laser, a Solvable Model.- Notes and References.- 4 Spontaneous Radiation by Atoms in Lasers.- 4.1. Introduction.- 4.2. Effects of Fluorescence in a Two-State Atom.- 4.3. The Fluorescent Spectrum.- 4.4. Correlation Effects.- Notes and References.- 5 Deflection of Atoms in Laser Fields and External Fields.- 5.1. Introduction.- 5.2. States of the Atom + Laser + External Field.- 5.3. Inclusion of Fluorescence.- 5.4. Inclusion of Center-of-Mass Motion.- 5.5. Discussion of the Force.- 5.6. Deflection by an Inhomogeneous Laser.- Notes and References.- 6 Potential Scattering of Charged Particles in a Laser Field.- 6.1. Introduction.- 6.2. States of the Free Electron.- 6.3. Formalism and the Born Approximation.- 6.4. A Theorem for Low-Frequency Lasers and Nonresonant Scattering.- 6.5. Resonant Potential Scattering in a Low-Frequency Laser.- Notes and References.- 7 Ionization.- 7.1. Introduction.- 7.2. Resonant and Nonresonant Two-Photon Ionization by a Weak Laser.- 7.3. Resonant Ionization for More than Two Photons.- 7.4. Angular Distribution of Electrons from Resonant Multichannel Ionization.- 7.5. Multiphoton Ionization in Multiple Energy Continua.- 7.6. Multiphoton Ionization in an Ultraintense Laser Field.- Notes and References.- 8 Electron-Atom Scattering in a Laser Field.- 8.1. Introduction.- 8.2. Formal Theory.- 8.3. Weak Resonant Laser.- 8.4. More Intense Resonant Laser.- 8.5. Intermediate-State Resonance.- 8.6. Low-Frequency Laser.- Notes and References.- 9 Atom-Atom Scattering in the Field of a Laser.- 9.1. Introduction.- 9.2. Degenerate Charge Transfer in the Field of a Laser.- 9.3. Laser-Induced Reactions.- 9.4. Nontransitory Resonance in a Weak Laser.- 9.5. Nonresonant Modification of Reactions.- 9.6. Modification of Long-Range Potentials.- Notes and References.- Appendix: The Effect of an Adiabatically Switched Laser on an Atom with a Continuum.