Chirped soliton solutions of Fokas-Lenells equation with perturbation terms and the effect of spatio-temporal dispersion in the modulational instability analysis

摘要

In the present work, exact chirped solitons are derived from the Fokas-Lenells equation with the perturbation terms which describes the ultrashort pulse in the optical fiber. The obtained chirps could help for either pulse compression or amplification in optical fiber. We also analyzed the effect of spatio-temporal dispersion in the modulational instability. As result, the modulational instability analysis shows that the gain is increasing when the spatio-temporal dispersion coefficient decreases; besides, the region of MI gain apparition is well determined.