High-speed optical transport: 100G and beyond [Series Editorial]

Telecommunications service providers continue to focus on providing additional network capacity to meet growing needs for bandwidth in their access, metro, and long-haul networks. Global optical transport industry suppliers have accelerated their efforts over the past three years on improving spectral efficiency while reducing cost per bit. While the industry has witnessed the growing use of advanced modulation formats such as DP-QPSK and coherent detection, a broad-based search for approaches to increase transmission speeds for each optical channel, a larger number of wavelength- division multiplexing (WDM) channels, and space multiplexing over a larger number of fiber cores is in progress.