The first comprehensive textbook on the optical properties of photonic crystals. It deals not only with the properties of the radiation modes inside the crystals but also with their peculiar optical response to external fields. Has consistently been a good seller (sometimes best-seller) at Optical Society of America meetings. Important recent developments such as the enhancement of stimulated emission, second harmonic generation, quadrature-phase squeezing, and low-threshold lasing are also treated in detail and made understandable. Numerical methods are also emphasized. Provides both an introduction for graduate and undergraduate students and also key information for researchers in this field. The second edition features a new chapter on superfluorescence and updated text and references throughout.