Mamyshev 2R regenerator
In 1998, Pavel V. Mamyshev of Bell Labs proposed and patented the use of the self-phase modulation (SPM) for single channel optical pulse reshaping and re-amplification.
It has been shown possible to advantageously replace the nonlinear fiber by a highly-nonlinear chalcogenide waveguide, therefore opening the way to all-integrated photonic chip regeneration.
Indeed, thanks to the quasi-instantaneous response of the nonlinear Kerr effect, this regenerator does not suffer from the finite recover time of some saturable absorbers.
In more details, low intensity pulses or noise do not broaden significantly and fall 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.
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),[8][9] a reduction of amplitude fluctuations can also be achieved, leading to power equalization of the pulse stream.
[9][10] Due to the spectral filtering process, the regenerated pulse is intrinsically shifted from the original frequency.
[12] 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.
In their work on Four-wave mixing (FWM) compensation by using a HLNF and its XPM, Michael Vasilyev and co-workers have proposed,[13] and demonstrated up to 12-channel optical regeneration in 10 Gbit/s systems.
[11] The Mamyshev regenerator may suffer from a poor yield : the spectral filtering of the expanded spectrum induces high intrinsic energy loss.
This technique has also been found beneficial in the field of ultrashort and high peak power pulse generation.
[22] Other example has been achieved with the contrast enhancement by several orders of magnitude of mJ femtosecond pulse in Argon-filled hollow core fiber.
[23] Concatenation of pairs of Mamyshev regenerators has been numerically studied and has shown that well-defined structures could spontaneously emerge from an oscillator architecture,[24][25] which has then been experimentally confirmed.
[26] Additional investigations have focused on the development of ultrashort high peak power fiber lasers [27][28] and other cavity designs have been considered.
