Limitations and challenges of single-carrier full 40-Gbit/s repeater system based on optical equalization and new circuit design

A single-carrier 10-Gbit/s system was installed into commercial networks and wavelength-division multiplexing technology was employed in laboratory tests to accelerate the transmission capacity to speeds of up to 1 Tera-bit/s. This successful transmission capability is based on high-speed circuit technology. This paper describes the problems and solutions for a single-carrier system with speeds of 40 Gbit/s or more. There are two major problems in implementing this system: one is how fast can electrical and photonic circuits operate and the other is how to accommodate certain kinds of dispersion limitations in long-haul transmission.