Self-focusing properties of chirped Gaussian pulse beams in media with normal dispersion

The self-focusing properties of the femtosecond pulse were analyzed through numerical calculation using modified Schr-dinger equation. On the basis of the analysis, the self-focusing properties of the chirped Gaussian pulse in the chirped pulse amplification (CPA) system were analyzed and discussed, and the numerical calculations were performed. The results showed that the effect of group velocity dispersion(GVD) on the pulse with large chip was slight and the effect of spectral width on the self-focusing properties could be ignored. Consequently, the self-focusing properties of the pulse with large chirp in the nonlinear medium with normal dispersion were different from those of femtosecond pulse, but similar to those of nanosecond pulse.