This comprehensive text describes the phenomenon of atomic coherence and the applications in several processes. Various sections have been written by eminent authors who have made extensive contributions in the field of quantum interference. Discussions are on microscopic nano-resolution techniques, lithography, photonic band gap control and much more. The Ebook is unique in its approach with experimental demonstrations and it should be a particularly useful reference for aspiring theoretical physicists, looking for a comprehensive review of applications in this active research field within a single book.