Highly nonlinear fiber-based lumped fiber Raman amplifier for CWDM transmission systems

Extreme statistics in Raman fiber amplifiers: From analytical description to experiments

“…The optical spectrum is also highly affected, experiencing a significant broadening caused by cross phase modulation of the pump on the signal. Such conclusions may find applications in the design of lumped Raman fiber amplifiers [46], especially in the case of wavelength multiplexed signals where the large number of channels under operation leads to rapid pump depletion and where each channel undergoes a different amount of walk-off as well as potential spectral broadening.…”

Extreme optical fluctuations in lumped Raman fibre amplifiers

“…In this section, we now focus our attention on the evolution of an initial 40 GHz pulsed signal with a temporal width of 6.25 ps, below the coherence time of the pump. The goal is here to evaluate the impact of a co-propagating pumping scheme on a discrete Raman amplifier that may be used in the context of new telecommunications windows that cannot benefit from standard erbium doped fibre technologies [45,46] or in the context of applications that require broad gain bandwidths [47]. Raman amplification can also be exploited to reinforce some nonlinear processing carried out in highly nonlinear elements [48][49][50].…”

Performance characterization of high gain, high output power and low noise cascaded broadband discrete Raman amplifiers

“…To improve the pump conversion efficiency, gain fibres with high Raman gain co-efficient and small core area are usually preferred in discrete Raman amplifiers. Dispersion compensating fibre (DCF), highly nonlinear fibre (HNLF) and dispersion shifted fibre (DSF) have already been used due to their high Raman gain properties [1][2][3]. Inverse dispersion fibre (IDF) has recently been proven as an alternative of DCF for in-line dispersion and nonlinearity management [4,5].…”

“…We investigated the performances of three different, commonly used Raman gain fibres: DCF, HNLF and IDF, in different combinations, and found that cascading HNLF 2km and IDF 6km as 1 st -2 nd stage configuration gave the best noise and nonlinear performance. Nonlinear impairment was calculated by determining the self-phase modulation (SPM) induced nonlinear phase shift (NPS) [3]. Noise performance was characterized by noise figure (NF) and output OSNR considering combined amplified spontaneous emission (ASE) and DRB noise contribution.…”