Influence analysis of the refractive index of air on the cross-correlation patterns between femtosecond pulses

The environmental parameters of refractive index of air and their effect on the cross-correlation model between femtosecond pulses propagation in air were discussed. Using the dispersion pulse propagation theory, the equation of cross-correlation between femtosecond pulses was obtained and the relation between the cross-correlation with the environmental parameters was established. Results show that the change of the atmospheric conditions gives rise to the change of the group refractive index, and then contributes to the shift of the correlations patterns without any extra linear broadening or chirp.