Effect of modified saturable nonlinearity on the instability spectra in Kundu–Eckhaus equation with the inclusion of SPM, inter modal, and XPM

Abstract

We examine the impact of intermodal dispersion on the modulation instability (MI) of an optical soliton in the Kundu-Eckhaus (KE) equation in the presence of cross phase modulation (XPM), modified saturable nonlinearity (MSNL), and self phase modulation (SPM). We consider the two component KE model with intermodal dispersion and MSNL, but without the four wave mixing term. Because the rays connected to various modes traverse the optical fiber at various effective lengths, intermodal dispersion arises in multimode fibers. As a result, light in the various modes spreads out temporally along the fiber. The MI criterion for the KE equation is established using the traditional linear stability analysis. When XPM and SPM are present, it is possible to determine, how inter modal dispersion and MSNL will impact the MI of an optical soliton in a birefringent fiber using the MI criterion. According to the findings, changed saturable nonlinearity significantly influences the MI dynamical behavior. In a typical dispersion scenario, an increase in the nonlinear saturation parameter can lead to an increase in the MI soliton. However, the anomalous dispersion regime exhibits the contrary behavior. In a two core birefringent KE model, the MSN and intermodal dispersion are capable of producing ultra-short pulses and a soliton. Our research will contribute to increasing the fiber optic telecommunication network's capacity and quality.