Ultrahigh-speed optical communications

Fiber-based ultrahigh-speed optical communications have achieved a remarkable level of success reaching multiterabit/s error-free transmission over several thousand kilometers. In the near future the total capacity is expected to approach a petabit/s. In this article critical issues that are involved behind the success of these achievements are reviewed and the future direction of ultrahigh-speed optical communications is discussed. The idea of the use of optical solitons for an information carrier is discussed comparatively with alternative approaches.