WDM Transmission Over Multiple Long Spans With Bidirectional Raman Pumping

We investigate the feasibility of WDM transmission over multiple spans that are twice as long as those typically used in commercial systems. Using longer spans reduces the number of repeater sites, potentially lowering the operating costs of medium- and long-haul terrestrial systems. We show that bidirectional Raman pumping is a key enabling technology. In particular, we demonstrate the benefits o...