Enabling optical devices for scalable networks: Introduction to the feature issue

Scalability in terms of both capacity and energy are gaining increasing focus as potential bottlenecks for future optical communication networks. Traffic growth is outpacing the rate of network efficiency improvements as well as the rate of optical system capacity improvement. Laboratory results are rapidly approaching the fiber transmission spectral efficiency limits. The energy efficiency benefits derived from Moore's law scaling are slowing. Research is under way today to address these challenges, covering the full range of technologies from devices to systems and networks. While many problems can be tackled by working independently within these areas, often important innovation comes from solutions that cut across such topical boundaries. Understanding device performance impacts and likewise network requirements can be essential to unlocking the critical ideas that lead to progress.