There has continuously been a massive growth of Internet traffic for these years despite the bubble burst in year 2000. As the telecom market is gradually picking up, it would be a consensus in telecom and data-com industries that the CAPEX (Capital Expenditures) to rebuild the network infrastructure to cope with this traffic growth would be imminent, while the OPEX (Operational Expenditures) has to be within a tight constraint. Therefore, the newly built 2r^-century network has to fully evolve from voice-oriented legacy networks, t only by increasing the transmission capacity of WDM links but also by introducing switching techlogies in optical domain to provide full-connectivity to support a wide variety of services. This book stems from the technical contributions presented at the Optical Networks and Techlogy Conference (OpNeTec), inaugurated this year 2004 in Pisa, Italy, and collects invations of optical network techlogies toward the 2V^ century network. High-quality recent research results on optical networks and related techlogies are presented, including IP over WDM integration, burst and packet switchings, control and managements, operation, metro- and access networks, and components and devices in the perspective of network application. An effort has been made throughout the conference, hopefully reflected at least partially in this book, to bring together researchers, scientists, and engineers working both academia and industries to discuss the relative impact of networks on techlogies and vice versa, with a vision of the future.