One of the first texts to offer a simple presentation of the theoretical foundations of steady-state laser spectroscopy, this volume is geared toward beginning theorists and experimentalists. It assists students in applying theoretical ideas to actual calculations in laser spectroscopy with a systematic series of examples and exercises. Starting at an elementary level, students gradually build up their practical skills with demonstrations of how simplified theoretical models relate to experimentally observable quantities. Detailed derivations offer students the opportunity to work out all results for themselves. The first chapter introduces background material on electrodynamics and quantum mechanics, with an emphasis on the density matrix, its equation of motion, and its interpretation. Chapter 2 derives the response of the medium to strong fields. After mastering these two parts, students can proceed to later chapters in any order they wish. Succeeding chapters cover the physical basis of laser operation, applications central to laser spectroscopy, the inclusion of laser fluctuations into the theory, and field quantization. Numerous references, which appear in separate sections, form a concise history of the field and its most noteworthy developments.