1,721,412 research outputs found
System advantages of Raman Amplifiers
Full text linkThe theory of Raman amplification is briefly reviewed together with the definition of Noise-Figure for distributed amplification. Erbium-Doped Fiber Amplifiers and Raman Amplifiers are compared on the basis of their non-linear impact. An optimal configuration for Hybrid Raman/Erbium-Doped Fiber Amplifier is derived for the design of multi-span systems. Results obtained through the analytical formalisms are compared with accurate simulation result
HFA optimization for nyquist WDM transmission
No full textWe propose optimization rules for HFA in NyWDM transmission over uniform uncompensated links, and for moderate pumping regime we introduce a fiber Raman merit parameter showing that noise reduction is always dominant on NLI enhancemen
Accuracy of Fiber Propagation Evaluation Using Phenomenological Attenuation and Raman Scattering Models in Multiband Optical Networks
Full text linkThe constant growth of IP data traffic, driven by sustained annual increases surpassing 26%, is pushing current optical transport infrastructures towards their capacity limits.
Since the deployment of new fiber cables is economically demanding, ultra-wideband transmission is emerging as a promising cost-effective solution, enabled by multi-band amplifiers and transceivers spanning the entire low-loss window of standard single-mode fibers. In this scenario, accurate modeling of frequency-dependent fiber parameters is essential to reliably describe optical signal propagation. In particular, the combined impact of attenuation variations with frequency and inter-channel stimulated Raman scattering (SRS) fundamentally shapes the power evolution of wide wavelength division multiplexing (WDM) combs and directly affects nonlinear interference (NLI) generation, as well as the amount of ASE noise.
In this work, we review a set of analytical approximations based on phenomenological approaches for frequency-dependent attenuation and Raman scattering gain, and analyze their impact on achieving an effective balance between computational efficiency and physical fidelity. Through extensive analyses performed with the open-source software GNPy (version 2.12, Telecom Infra Project) on an optical line system exploring multi-band scenarios spanning C+L+S, C+L+E, and U-to-E transmission, we demonstrate that the proposed approximations reproduce the reference SRS power evolution and NLI profiles with root mean square errors (RMSEs) consistently below 0.03 dB, and down to the 10^-3 to 10^-2 dB range for the most accurate configurations.
Although the current implementation does not yet provide a direct reduction in computational time, the proposed framework lays the groundwork for future developments toward closed-form or semi-analytical solutions, enabling more efficient modeling and optimization of ultra-wideband optical transmission
Raman Crosstalk Suppression in NG-PON2 Using Optimized Spectral Shaping
Full text linkIn this paper, we present an innovative proposal to mitigate the effect of Raman crosstalk in the interaction between NG-PON2 TWDM-PON channels and legacy RF-video by electrical spectral shaping on the TWDM NRZ data stream obtained through electrical FIR filtering. We find an analytical and closed form solution on FIR filter taps that, for a given target spectral shaping, gives the absolute minimum amount of intersymbol interference on the TWDM data. Then, we propose techniques to implement these FIR filters with reasonable system complexity. We found that our proposed technique is applicable to all classes (up to E2 PON, +11 dBm transmitted downstream power) with less than 0.5 dB power penalty on TWDM channels even in the worst-case scenario of RF-video still based on analog channels on the lower part of the spectru
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