When this publisher offered me the opportunity to \\Tite a book, some six years ago, I did not hesitate to say yes. I had just spent the last four years of graduate school struggling to understand the physics of strained quantum well lasers, and it seemed to me the whole experience was much more difficult that it should have been. For although many of the results I needed were easy to locate, the underlying physical premises and intervening steps were not. If only I had a book providing the derivations, I could have absorbed them and gone on my way. Such a book lies before you. It provides a unified and self-contained descrip tion of the essential physics of strained quantum well lasers, starting from first principles whenever feasible. The presentation I have chosen requires only the standard introductory background in quantum mechanics, solid state physics, and electromagnetics expected of entering graduate students in physics or elec trical engineering. A single undergraduate course in each of these subjects should be more than sufficient to follow the text. :'Iore advanced material on quantum mechanics is developed and collected in the first chapter. \Vhen pos sible, I have presented the results in a general setting and have later applied them to specific cases of interest. I find this the most satisfying way to ap proach the subject, and it has the additional benefit of solving many problems once and for all.

Physics of Strained Quantum Well Lasers provides an extremely detailed, accessible, and clear account of the fundamentals of the subject. This self-contained presentation progresses from strained quantum well bandstructure to device physics. It is specifically tailored to the background and needs of incoming graduate students in electrical engineering and physics, as well as industrial research and development engineers. Only a standard undergraduate knowledge of quantum mechanics, solid state physics, and electromagnetism is required. No prior familiarity with lasers is needed. The first chapter of Physics of Strained Quantum Well Lasers is a mini-course on advanced quantum mechanics, and explains the most important techniques. Perturbation methods, both time-independent and time-dependent, are developed in detail, making the rest of the material much easier to understand. In later chapters, particular attention is paid to some of the most challenging and important topics, such as the kA-p theory, the deformation potential theory, the multiband envelope function approximation, field quantization, and the emission and absorption of light in quantum wells. These core topics apply widely, both to quantum well lasers and to other electronic and optoelectronic devices. Physics of Strained Quantum Well Lasers will allow the reader to progress systematically through the text and emerge with enough knowledge to successfully understand and model strained quantum well lasers.