Quantum Electronics: A Treatise, Volume I: Nonlinear Optics, Part A deals with the theoretical and experimental aspects of the nonlinear optical susceptibilities and process. This volume is composed of two parts encompassing seven chapters. After a brief overview of the field, this book goes on discussing experimental determination of the susceptibility coefficients and numerical values for a variety of materials appearing in the nonlinear constitutive relationships. The second part describes several nonlinear optical phenomena to which these nonlinear susceptibilities give rise. The characteristics of these basic nonlinear interactions are also presented in a unified and cohesive manner. This book is of value to quantum electronics scientists, engineers, and researchers.