Propagation of chirped ultra-short optical pulses

Abstract

Ultra-short optical pulses having initial linear chirp in nonlinear guides are discussed. The Nonlinear Schrodinger Equation for complex initial conditions is solved numerically by Split-Step Fourier Method and Beam Propagation Method. Some selected results for solitons are presented. The computations confirm physical expectations of an influence of the chirp magnitude on pulse propagation in nonlinear guide.

Transformation of chirped square pulse into soliton

“…If initial pulse is a square function the stationary value of the fluctuation is higher in case of negative chirp. Also frequency of this fluctuations for the same value of the chirp parameter is greater for square pulse than it is for soliton or for Gaussian pulse [10],[l 1]. Because the stationary value of the fluctuation in case of square pulse is higher then in the other case, it can be presumed that critical value of the chirp parameter will be greater precisely for the square pulse.…”

“…Generally, initial chirp is undesirable phenomenon. When analyzing hyperbolic secant [10] and Gaussian pulse [1 1], both positive and negative chirp have the same effect for appropriately long propagation distance. If initial pulse is a square function the stationary value of the fluctuation is higher in case of negative chirp.…”