Compression d’impulsions symétriques et asymétriques chirpées dans les Fibres à Grilles de Bragg.

Abstract

In this work we present the compression of chirped symmetric and asymmetric pulses in nonlinear fiber Bragg gratings (FBGs). The dynamics of these fibers is modelled by nonlinear Schrödinger equation (NSE) with group velocity dispersion (GVD) whith exponentially decreasing dispersion and cubic nonlinearity. Indeed, we derive the equation governing the evolution of the pulse parameters for different ans ̋atze studied (hyperbolic secant, gaussian and Airy pulses) with the lagrangian variational method (LVM). The analysis of the different regimes of propagation is also made. Then, we present in 3D different profiles used and eventually compare the results obtained with different profiles for GVD. The compression factor obtained with asymmetric pulses is better than the compression factor obtained with symmetric pulses. Finally, we show the importance of chirp in the process of pulses compression.