Engineering an Extended Gain Bandwidth Hybrid Raman—Optical Parametric Amplifier for Next Generation CWDM PON

We describe a model and present simulation results for the optimization of an extended amplification bandwidth hybrid Raman-Optical Parametric amplifier (HROPA) in Tandem configuration. In this configuration, the Raman and Parametric processes are separated and each one takes place in a separate span of fiber, allowing for optimization of amplification gain (e.g., > 20 dB), gain bandwidth (e.g., 170 nm) and gain ripple (e.g., <; 4 dB). We also focus on the potential signal degradation performance due to the generation of idlers within the operational bandwidth. To overcome this limitation, we propose and model a modified HROPA design, which allows for the management and the suppression of idlers in the amplifier. The idler suppression is achieved through partitioning the channels in two sub-bands and using a wavelength-division multiplexed DEMUM/MUX pair to limit/suppress the idlers, as well as crosstalk terms generated in the amplifier. Our study shows that with proper selection of pump wavelength and power and engineering the HROPA with correct filter transfer function, we can achieve error free performance even in the case when significant misalignment of the transmitter wavelength from the center of the coarse WDM channel band exists.