Bright and dark optical solitons in coupled higher-order nonlinear Schrodinger equations through singularity structure analysis

A fairly general form of coupled higher-order nonlinear Schrodinger (CHNLS) equations, which includes the effect of group velocity dispersion (GVD), third-order dispersion, Kerr-law nonlinearity and describing a large class of phenomena involving soliton interactions, has been investigated using Painleve (P) singularity structure analysis in order to identify the underlying integrable models. The identified integrable models agree well with those obtained from AKNS formulation. In addition, we explicitly obtain the bright and dark N-soliton solutions for the integrable model by using Hirota bilinearization derivable from the P-analysis. The form of the bright one-soliton agrees with the result derivable from the inverse scattering analysis, while that of the remaining higher-order bright solitons and dark N-solitons are reported for the first time, by including the most general linear coupling terms