Abstract
We investigate the dynamics of ultrashort pulses in nano optical fibers that is governed by improved nonlinear Schrodinger equation with dual-power law nonlinearity with Hamiltonian perturbation terms. A set of entirely new soliton solutions with nonlinear chirp is derived for the first time. The chirped solutions comprise of bright, dark and singular soli tons, illustrating the potentially rich set of localized structures with nontrivial phase for the improved model. It was shown that the nonlinear chirp associated with each of these optical solitons is dependent on the pulse intensity. The restrictions on physical parameters for the existence of chirped soliton pulses are also listed. (C) 2017 Elsevier GmbH. All rights reserved.