"The purpose of this thesis is to investigate, by means of numerical simulations, soliton pulse compression and soliton self-frequency shift. Those physical phenomena are related to higher-order solitons propagation. This study in particular was performed in hollow-core photonic bangap fibers, and involves both designing and characterizing the fibers by means of their spatial parameters. A second stage consists in the study of soliton pulse propagation along the fiber and, as a consequence, the analysis of the desired phenomena. In particular, this work focus in the quality of the output pulse. Firstly a brief introduction of hollow-core photonic bandgap fibers and theirs applications are shown: particularly soliton pulse compression and soliton selffrequency shift. Later a numerical investigation on the influence of tapering the fiber on its dispersion parameters, effective areas and non linear parameters are presented. Then the theoretical fundamentals for the study of soliton pulse propagation are given, as well as the mathematical expressions to quantify it. Finally the soliton evolution is studied by solving the generalized Schr¨odinger equation. On the one hand, a numerical study of the compression of femtosecond unchirped pulses, at 800 nm is presented. Here the effects of tuning the cross section size of a HC-PBGF on the modal parameters in order to have a fiber structure which promotes pulse compression is studied. It was found that a tuning of the cross section size of the fiber with a tapering factor of 4.5% produces a maximum compressed pulse with a compression factor of 5.7 with a temporal FWHM of 153.8 fs. The pulse reaches a peak power of 1.5851 MW with 77% of pulse shape quality. The length fiber at which the compressed pulse is reached is of 31 cm."