Transient second-harmonic generation: influence of effective group-velocity dispersion

Second-harmonic generation using high-intensity ultrashort pulses is studied numerically. In a highly dispersive medium and for ultrashort (subpicosecond to femtosecond) fundamental pulses the effective group-velocity dispersion (GVD) as well as the group-velocity mismatch should be taken into account. The numerical results indicate that in this case the conversion efficiency is reduced, compared with the case when only the group-velocity mismatch is taken into account, and for somewhat larger values of effective GVD parameters it exhibits an oscillatory behavior. Fundamental and harmonic pulse shapes inside the medium are also calculated. The cases with the effective GVD taken into account show that inside the medium both of the pulses split into two or more pulses.