Raman amplification: Key enabler for next-generation flexible optical networks?

The ever-increasing demand for capacity in optical networks is driving the development of transponders capable of achieving spectral efficiencies of up to 8 bit/s/Hz using advanced modulation formats and coherent-detection. However, operating at the highest spectral efficiency is accomplished at the expense of shorter transparent reach, potentially requiring the deployment of additional expensive optical signal regenerators (3Rs). This limitation can be mitigated to a certain extent by exploiting enhanced optical amplification strategies, such as Raman amplification. Interestingly, the prevalent paradigm of only using Raman amplification in the longer fibre spans of long-haul networks may be on the verge of being challenged. This paper provides insight on the potential of Raman amplification in next-generation flexible optical networks by showing the network-level benefit provided by Raman amplification when transmitting a wide assortment of channel formats in meshed optical networks.