SOA-based optical switches

Optical switches are fundamental building blocks for high-speed optical networks and basic blocks towards all-optical networks for future communications that utilize wavelength division multiplexing (WDM) with high-speed multiple modulation formats to boost the single-channel data rate to hundreds of Gbps. Photonic switching based on semiconductor optical amplifiers (SOA) is one of the most promising switching technologies, featuring nanoseconds of switch configuration time, amplification, and small footprint due to photonic integration. We can arrange these SOA switching components into some interferometric architectures in which SOAs achieve an efficient optical switching rate with low control energy and large optical sampling bandwidth. To organize this chapter, we review many works worldwide with special attention to the work underway at the Eindhoven University of Technology to characterize SOA-based optical switches as processing elements in practical optical switching networks. The goal of this chapter is to present design criteria, improvement of the performance, and integration of the SOA-based switches. We begin with a description of SOA-based switch architectures in the first section. The physical structure of an SOA, its features and characteristics, are presented in the second section. Some techniques for SOA design improvements and a study of the noises in SOA-based switches are presented in the fourth section. The deployment of SOA-based optical switches in optical switching networks is presented in the fifth part. Finally, we summarize the chapter and provide an outlook of future applications. This chapter will cover SOA-based optical switches from the fundamentals to recent developments, which is an important part of the topic of "Optical Switching: Device Technology and Application in Networks". This chapter will provide quick expertise on the most recent SOA switch technologies for researchers, senior graduate and postgraduate students, and professionals working in the telecommunications industry.