Impact of external potential and non-isospectral functions on optical solitons and modulation instability in a cubic quintic nonlinear media

We investigate the non-isospectral generalized higher order NLS equation (GHNLS) with external potential which is unswervingly represents the ultrashort optical soliton transmission in inhomogeneous non-Kerr media with combined effects of external potentials. Lax pair is constructed for GHNLS equation and three soliton solutions obtained with the aid of Darboux transformation. For the first time, we include the effects of inhomogeneous non-isospectral parameters on soliton dynamics. Using two soliton solutions, interaction among double hump solitons and using three soliton solutions, interaction characteristics are studied analytically. Furthermore, in order to understand the stability mechanism, linear stability analysis also has been performed. Effects of nonisospectral parameters and variable coefficients on soliton dynamics are investigated graphically. The predicted results may be observed in the future experiments on nonlinear fiber optics and applications to femtosecond soliton management. (c) 2022 Elsevier Ltd. All rights reserved.