outside of the off-centered BPF and hence the output for the noisy 0's in the data stream are reduced to the zero floor. On the contrary, for the 1's data pulses the intensity is sufficiently strong to broaden the spectra by SPM, and a significant portion of the spectrum falls into the OBPF passband, leading to a generation of the output 1's pulse. For a careful design of the regenerator and an appropriate combination of filter parameter (spectral offset and bandwidth) / fiber parameter (length, dispersion and nonlinearity values), a reduction of amplitude fluctuations can also be achieved, leading to power equalization of the pulse stream. The modelling results for the 2R regenerator are shown with the article. In Figure 1, the upper panel shows regenerated pulse from the input (lower panel) for the Mamyshev 2R regenerator. The noisy 1's pulses are boosted to same power levels in the output, while the 0's pulses are reduced to the noise floor. An important property of a Mamyshev regenerator is its transfer function that links the output peak power to the input peak power. For an efficient operation and power equalization, this transfer function should exhibit a marked plateau at the 1's power level. Example of a transfer function is provided Figure 2. The spectral operations of broadening, filtering and regeneration about the central wavelength are shown in Figure 3. In the design of this nonlinear regenerator, care should be given to avoid the consequences of deleterious Brillouin backscattering as well as pulse to pulse interaction leading to patterning effects in the output sequence. Mamyshev regenerator - Variants Due to the spectral filtering process, the regenerated pulse is intrinsically shifted from the original frequency. This can be beneficial if wavelength conversion is to be achieved simultaneously the regeneration and therefore channel switching can be considered. However, if one wants to recover an output signal having the initial wavelength, an option of applying another regeneration with the BPF center frequency placed at the original channel center frequency allows to overcome this problem. This can be done in a single fiber using a bidirectional propagation in the nonlinear fiber. Multichannel 2R Regeneration The Mamyshev regenerator in its standard configuration is limited to single-wavelength operation in order to prevent from cross-phase modulation (XPM) effects from adjacent channels. Several schemes have been proposed to extend its region of operation to multichannel regime. In their work on