Symmetry Enhancement Through Advanced Dispersion Mapping in OPC-Aided Transmission

Abstract

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Lumped Compensation of Nonlinearities based on Optical Phase Conjugation

“…17 allows additional freedom in designing the system. As shown in [25], [32]- [34] and further discussed in the following sections, fibers with opposite signs of dispersion can be considered for the links before and after the OPC. Such links are not fulfilling the condition provided by Eq.…”

“…Moreover, it is noted that the system in Fig. 2 employs fibers with opposite dispersion signs on each side of the OPC, as discussed in [25], [32]- [34]. This allows for the OPC symmetry to be achieved using simple lumped amplification -by e.g.…”

“…The degree of symmetry, however, varies depending on the considered system scenario. Due to exponential power decay in both spans, matching the slopes in NADD requires that the link and the compensation fiber have opposite dispersion signs [25], [32]- [34], which is the case for System2 and System3, though not for System1. Despite this limitation, and even though the OBP addresses only a small fraction of the link due to low β, substantial gains are still demonstrated for all three cases, as illustrated in Fig.…”

“…OPC is based on degenerate four-wave-mixing (FWM) in a strained highly nonlinear fiber (HNLF) using bidirectional loop configuration to ensure polarization insensitivity, as in [24], [26], [32], [42]- [44], and it is accompanied by a wavelength shift from 1540 nm to 1550 nm. The conversion efficiency in the HNLF is approx -6 dB, sufficient to yield a low back-to-back conversion penalty below 0.5 dB in SNR, which becomes negligible in transmission [45]- [47].…”

Asymmetry Optimization for 10 THz OPC Transmission over the C + L Bands Using Distributed Raman Amplification

“…To maximize its efficiency when applying it to multi-channel nonlinearity compensation, there are a few approaches which will need to be implemented on the fiber link. For example, in [ 15 , 16 ], the fiber nonlinearity compensation using a mid-link OPC can be achieved using a symmetrical chromatic dispersion slope or effective management of dispersion mapping before and after the OPC. Alternatively, in [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ], with a purposefully designed distributed Raman amplification scheme, a symmetrical signal power profile along the fiber before and after the OPC was demonstrated to maximize the effectiveness of nonlinearity compensation with a mid-link OPC.…”