Photography is a well-known example of changing a material by exciting it with light. This book examines a special case of a more general approach, which uses new lasers or electron beams to address some of the current needs emerging in microelectronics, photonics, and nanotechnology. It analyzes the important features of the changes induced by electronic excitation, identifies what is critical, and provides a basis from which materials modification can be developed successfully. It addresses ideas such as energy localization and charge localization, with detailed comparisons of experiment and theory. It also identifies the ways this understanding links to technological needs, such as selective removal of material, controlled changes, altering the balance between process steps, and possibilities of quantum control. This book will be of particular interest to research workers in physics, chemistry, electronic engineering and materials science.