Boukri, Mohammed2020-02-022020-02-022019-06-27salle des thèsesMS-530-62-01https://dspace.univ-tlemcen.dz/handle/112/15365In this work we have presented a study of some non-linear phenomena that occur at optical fibres during the propagation of an ultra-short pulse "Electromagnetic wave" . The notions of Maxwell's equations, the propagation equation of an electromagnetic wave and the notion of soliton allowed us to derive a model known in optics as the Non-Linear Schrödinger (ENLS) which will take into consideration the dispersion and non-linearity effects. The analytical solution of such equation is difficult and sometimes impossible, which is why a numerical method is used, considered to be the most appropriate tool to solve this type of problem, called the "Split Step Fourier Method" SSFM. A numerical simulation allowed us to describe the evolution of a pulse in an optical fiber while revealing the advantage of the coexistence of the two phenomena "dispersion and non-linearity of the medium".frNLSE-SSFM Method-Soliton-PBR(pulse Broadening Ratio)-Optical fiber-Nonlinear effects-Chirped PulseENLS-La méthode SSFM- Soliton- PBR(rapport d'élargissement de l'imulsion)-fibre optique- effets non linéaire-impulsion chirpéeThesis