The high capacity transport infrastructure that underpins today's Internet utilizes optical wavelengths both to provide high capacity transmission by means of multiplexing many wavelengths, each carrying as much as 100 Gb/s on a single wavelength, but also to provide coarse networking flexibility by dynamically adding, dropping, and routing wavelength channels. Viewed initially by many as little more than a dreamlike vision, these wavelength switched networks have now been deployed in both metro and long-haul networks around the globe to provide flexible, cost-effective high bandwidth connectivity to meet the explosive growth in demand of very broadband wire line and wireless services, especially video. The success of these networks, as signified by their ubiquitous deployment, is a result of a fortuitous combination of three factors: 1) a new network vision that, with the help of optical switching elements, leverages the advantage of optical amplifiers at the network as well as the transmission systems level; 2) technological advances that made possible the required cost-effective wavelength selective optical switching modules; and 3) continued massive demand growth that has driven the need for full wavelength capacity connectivity between network nodes that makes realizable the high value proposition for these wavelength routed networks. In this paper, we provide a historical perspective on the evolution of optical networks, with some emphasis on the Defense Advanced Research Projects Agency (DARPA)-funded Multiple Wavelength Optical Network (MONET) program, which demonstrated the technical feasibility of wavelength-division multiplexing (WDM) optical networks. We also discuss the value proposition of optical networks as well as their critical network elements and their enabling technologies. We also highlight the current status of these networks from a commercial deployment as well as the next generation research point of view.

A review is presented of electrooptic waveguide switch arrays with strong emphasis on those based on titanium-diffused lithium niobate waveguides. Crosspoint and array design considerations and performance are discussed as are waveguide technology limits. Switch array demonstrations are reviewed. Experimental demonstrations of switch arrays are described and particular parameters of the array, including insertion loss, crosstalk, and switching voltage achieved by several laboratories, are discussed and compared. Results of high-speed switch arrays are also described.>

Provides an overview of the technical articles and features presented in this issue.