Chapter 2Ultra-fast all-optical switching in optical networks

Abstract

This chapter discusses the ultrafast all-optical switching in optical networks. All-optical switching takes advantage of a nonlinear interaction between optical waves. The nonlinearity in a variety of materials including fiber, semiconductors, and crystals like lithium niobate has been used to demonstrate all-optical switching. The chapter presents some key techniques developed for ultrafast switching and experimental results demonstrating their switching capabilities. The semiconductor optical amplifier (SOA) is a key component for optical signal processing in optical communication and networks. SOA-based devices are compact and offer the possibility for monolithic integration together with other photonic devices. The short length of the SOA reduced the problem of phase mismatch. SOAs are used as building blocks in all-optical demultiplexers, switches, wavelength converters, memories, and dispersion compensators. With the further development of SOA fabrication technologies, SOAs with low polarization sensitivity and high saturation output power have been developed, resulting in improved performance. The chapter also describes the use of ultra-high-speed all-optical switches in several applications.