Potential of Hollow-Core Fibers to Reduce Number of in-line Amplifiers in Optical Transport Networks

Hollow-core fibers (HCF) technologies are evolving rapidly and becoming a candidate for next generation deployable optical fibers. This type of fibers has several advantages compared with traditional ones, e.g., reduced latency, very low nonlinearities, and theoretical lower loss profile. Conversely, as they are sill under development, some uncertainties are present, like their actual loss profile and costs of fabrication/deployment. Moreover, exploiting their potential for improved reach/capacity requires optical amplifiers with higher maximum total output power. Interestingly, HCF proprieties could be leveraged to simplify the optical network infrastructure by reducing the number of in-line amplifiers. This work assesses the potential of HCF to reduce the total number of in-line amplifiers, without compromising end-to-end performance and considering the loss coefficient uncertainty, in reference optical transport networks. Simulation results provide evidence that significant savings in in-line amplifiers are possible, while also guaranteeing high traffic load supported and reduced number of interfaces required, provided that high-power amplifiers and HCF with a loss coefficient equal or lower than traditional silica-based fibers are commercially available.