This volume focuses on a research field that has emerged in the last decade as one of the most promising and rapidly advancing. The interest towards photonic crystals and metamaterials and their strategic importance are evident in the steadily growing rate of topical publications, the recent creation of topical journals, conferences and workshops promoted by several scientific societies, the research efforts at international level, and the number of proposed novel applications based on them.The various contributions, by renowned scientists from academia and industry, address wide-ranging topics, including aspects pertaining to modeling, phenomenologies, experiments, technologies and applications.