Effects of saturable function in three-core PIM-NIM-PIM coupler through modulation instability

摘要

We consider a model of three-core PIM-NIM-PIM coupler with Kerr-type saturable nonlinearity to study both analytically and numerically saturation effects on the modulational instability (MI) phenomenon. The analytical results show us that, in presence of saturable parameters in normal and anomalous dispersion regime the instability gain presents significant changes compared to Shafeeque et al. (Phys Lett A 11:223-229, 2015) in absence of saturable parameter. It clearly also shows that Power and nonlinear parameters can be used to control MI. Through numerical simulation, the generations of periodic soliton are obtained in presence of nonlinear saturation. However in absence of saturable parameter, the train of soliton obtained turns into a turbulent state after a certain propagations distance, and in that case, the system is prone to present MI.