Approximation of mode profile dispersion in the generalized nonlinear Schrödinger equation superior to the constant overlap approach for weakly guiding fibers

An efficient numerical approach to nonlinear propagation in waveguides based on an approximation of the overlap integrals’ frequency dependence is proposed. Two test cases are studied: a weakly guiding step-index fiber and parabolic-index fiber, where compared standard neglecting calculating overlaps at center wavelength λ 0 , benchmarked against Gaussian quadrature approach, whose accuracy can be increased systematically. We believe that combined efficiency proposed make it superior other two approaches few-mode simulations.