This book discusses the techniques of processing and manipulating signals propagating in the optical domain. Photonic components essential for photonic processing systems are included as well as the representation of photonic circuits. Photonic signal processors and their applications for the generation of solitons, and the application of these solitons in optically amplified fiber transmission systems, are discussed. Compensation dispersion using a photonic processor, the design of optical filters using photonic processor techniques, and the filtering of microwave signals in the optical domain are illustrated.