Simple design method for gain-flattened three-pump Raman amplifiers

Abstract

We propose a simple and efficient approach to the design of 3-wavelength backward-pumped Raman amplifiers with increased gain flatness over a wide spectral band. Three different methods dealing with the optimization of one or two different simple parameters are studied. Various examples are provided for illustration, and the dependence of both amplifier gain and gain flatness with pump power is shown. Gain flatness in the spectral range of 1,520-1,595 nm of about 1 dB for a 7.5 dB gain and of 1.8 dB for a 13.5 dB gain is demonstrated using only three pumps with wavelengths within the 1,420-1,480 nm interval.

Performance improvement of broadband distributed Raman amplifier using bidirectional pumping with first and dual order forward pumps

“…In Figure 1(c), 2 nd order forward Raman pumping has been considered: both 1365 nm and 1425 nm pump wavelengths are used, with the 1425 nm pump acting as a seed which is amplified by the 1365 nm pump and finally amplifies shorter wavelength signals in order to improve the ASE noise performance of the amplifier. The full numerical model for the evolution of WDM pumps and signals is based on the standard model presented in [7,8] and also extended for OSNR evolution and optical NF calculation at signal wavelengths. All important effects such as stimulated and spontaneous Raman scattering, pump depletion, ASE and double Rayleigh scattering (DRS) noise, energy transfer due to pump-pump, pump-sig and sig-sig interactions from either directions are included in the model and described in the following equation: where P ± represents the power within the frequency interval Δν either forward (+) or backward (-) propagating direction at centre frequency ν. α ν and ε ν are the fiber attenuation and Rayleigh scattering coefficient at frequency ν respectively.…”

“…semiconductor pump lasers) because data transmission performance can be highly degraded by the impacts of RIN transfer at higher pump powers [6]. In order to achieve a low intra-span signal power variation, higher or dual order pumping can be used to distribute the gain more evenly along the span, leading to better optical signal to noise ratio (OSNR) and noise figure (NF) performance [7][8][9]. The benefits of higher order pumping have also been demonstrated in [10,11] in terms of extended reach of data transmission where transmission bandwidth was limited in C-band.…”

Experimental Characterization of Raman Amplifier Optimization Through Inverse System Design

“…Some proposals break the design problem into two simpler inverse problems: firstly finding the pump wavelengths using genetic algorithm and secondly finding the pump powers iteratively solving the ODEs [9]. Others reduce the parameters to be adjusted aiming at simplifying the inverse design problem by adjusting groups of laser pumps instead of each one individually [13], [14].…”

Multi–Band Programmable Gain Raman Amplifier

“…The challenge with Raman amplifier design is on the selection of pump powers and wavelengths that would result in a targeted gain profile. Several solutions to this optimization problem have been reported in the literature but have mainly focused on realizing flat gain profiles [24]- [32]. Recently, a machine learning framework for the ultra-fast configuration of the pump powers and wavelengths has been theoretically proposed and as a proof-of-principle experimentally demonstrated in Cband only [33], [34].…”