This book focuses on the design, modelling and demonstration of a synchronous optical buffer for an optical packet switch, placed in the core of an optical transport network. An overview of the future optical networks is addressed, presenting the incentives to achieve the next generation optical packet-switched networks. Emerging technologies for signal processing in optical switches are introduced as an alternative to provide better features to the packet switch architecture. A novel and simple technique for optical buffering is chosen as part of the contention resolution method within the packet switch. This scheme is examined through modelling and experimentally, and is compared to other contention resolution techniques. Architectural issues concerning the structure of the optical buffer are discussed and the various subsystems of the final model are presented. The buffer limitations are examined and design rules are discussed. Finally, the simulation of a packet switch using this type of optical buffer is presented, proving its feasibility and functionality.