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

Wavelength-Enhanced Passive Optical Networks with Extended Reach

“…However, commercial deployment will likely be a challenge due to its complexity, high component count, and reliance on immature technology. Another solution, a discrete Raman amplifier [8], also covered the 8-channel CWDM band, but had lower gain and is faced with the same component-count issues. We have demonstrated a discrete hybrid amplifier in an "extender box", which includes both SQA and Raman amplifier stages, to amplify signals with wavelength ranges larger than the effective range of current optical amplifier technologies.…”

Performance of lumped fiber Raman amplifiers using highly nonlinear fibers or nonlinear photonic crystal fibers

“…OSNR and noise figure are used to describe the noise performance of LFRAs, and OSNR is calculated in 100 GHz bandwidth. [3], [4], which has: fiber loss of 0.46dB/km, and fiber core effective area of 9.5 2 m µ both at 1550 nm. Its Raman gain coefficient has a peak value of 7.2 ( )…”

“…, and a twice larger ratio of R eff g A to loss compared to DCF [3], [4]. In addition, it was found experimentally that highly nonlinear fiber can be used for noise suppression in Raman amplification [5].…”

Erbium doped fiber and highly non-linear fiber based on bismuth oxide glasses

“…For the CWDM system, a wide-band amplifier is needed since the channel spacing of the wavelength grid is 20 nm, and each channel should have a wide tolerance due to the wavelength fluctuation of laser diodes. The amplification of CWDM signals has been demonstrated using fiber Raman amplifiers (FRAs) and rare-earth doped amplifiers [23,24]. An 8-channel CWDM amplifier that has the output power of 19 dBm has been reported using FRAs.…”