A correction method for the analytical model in Raman amplifiers systems based on energy conservation assumption

Thiago V N Coelho,Alexandre Bessa Dos Santos ,C C Luiz ,Maria José Pontes ,Marco Aurélio Jucá ,Andrés Pablo López Barbero

doi:10.1590/2179-10742016v15i3612

Abstract

This paper presents a modification for the already consolidated analytical model that calculates the gain and ripple in multi-pump Raman amplifiers by considering energy conservation. The original analytical model precisely computes the pump-pump interaction to the C- and L-band for a WDM input signal. However, when this method is used to amplify a large bandwidth, as the entire C and a part of the L band, the increase in the number of pump lasers impacts the obtained results. The error, if compared with results obtained by a numerical method, becomes significant. An analysis in terms of energy is proposed to minimize the discrepancy between analytical and numerical results. An improvement is observed to the gain results.

Highlights

Long distance optical networks are responsible for creating a demand for broadband optical amplification technologies
A numerical model was implemented by Cani et al [8] based on coupled differential equations that describe the spatial propagation of multi-pumps and multi-signals in a Raman amplification environment which include all the meaningful physical parameters for the performance analysis in the continuous wave (CW) regime
The amplification occurs in a 50 km optical fiber with the parameters used for a standard Corning single mode fiber (SMF) fiber

Summary

INTRODUCTION

Long distance optical networks are responsible for creating a demand for broadband optical amplification technologies. The transfer of instability noise from the optical pump to the optical signal is lower, the gain dependence with the polarization state is less important and the amplification occurs when the signal is not excessively intense; the problem of non-linear effect is less significant This latter characteristic can be a negative factor because the signal to be amplified can be at the same level of the noise floor. A numerical model was implemented by Cani et al [8] based on coupled differential equations that describe the spatial propagation of multi-pumps and multi-signals in a Raman amplification environment which include all the meaningful physical parameters for the performance analysis in the continuous wave (CW) regime This model with a large number of pumps and signals could demand high costs in computational resources. This will permit the use of this method in optimization techniques to ensure the optimal design of the gain bandwidth for broadband optical networks

MATHEMATICAL MODEL

Corrected Model

RESULTS

CONCLUSIONS