The Nonlinear Optical (NLO) Materials have become the smartest materials of the present era, since they have replaced the electrons by photons as information careers. NLO active materials have versatile properties to generate new electromagnetic fields with new frequencies, phase, or other physical properties by the interacting with intense laser light. The NLO materials have several potential applications in modern optical data storage, holographic imaging, frequency mixing, telecommunications, and so forth. This book provides an up-to-date and comprehensive knowledge of molecular level...