<title>Link control protection of surviving channels in distributed fiber Raman amplifier cascades</title>

Abstract

In this work, by means of numerical simulation, the application of the link control protection technique on power transient suppression in cascades of distributed fiber Raman amplifiers (DFRAs) is investigated. The results point out that for a 10 DFRA's cascade, the power excursion in the surviving channels, at the 10th amplification stage, is reduced by 2.15 dB to 0.037 dB, when 8 out of 10 channels are involved in add/drop operations.

Per-band link control transients protection in distributed fiber Raman amplifier cascades

“…Hence, the load on all amplifiers of the link is also constant, avoiding power transients. The control circuit is a proportional-integrative electronic control, whose mathematical representation is [10]:…”

“…The parameters k p and t, represent the gain of the proportional and integrative error, respectively, which are used in the feedback loop. The error function R(t) is defined as [10] :…”

“…In order to evaluate the performance of the proposed method when controlling transients in DFRAs , we have used the dynamic model of DFRA derived in [10] for our simulations. This model takes into account the generation and propagation of spontaneous emitted noise, generated by spontaneous Raman scattering process.…”

“…In this case, we analyze the situation when the classical link control scheme is used [10]. For that, 9 and 18 out of 20 channels are added/dropped at the input of the first DFRA.…”

“…These two independent PI controllers are described by the following equations [10]: Figure 6. Power excursion of surviving channel (Ch, I, 1645 nm) at the output ofDFRA#IO, with per-band link control on/off when 9 and 17 out of20 WDM channels arc dropped/added, DFRA #10 into the cascade, when 9 and 17 out of 20 channels are added/dropped.…”