We study the transient behaviour of a degenerate four-wave mixing process in a saturable nonlinear medium where the laser induced refractive index change is given by Δn = n2I/(1+I/Is). The theoretical model we develop can be applied for any complex value of n2 which contains absorptive, dispersive or mixed components. This model explains very well our experimental results in GdAlO3:Cr3+, using n2 and Is values that are in good agreement with previous measurements.
De Souza, P. C., Nader, G., Catunda, T., Muramatsu, M., & Horowicz, R. J. (1999). Transient four-wave mixing in saturable media with a nonlinear refractive index. Optics Communications, 163(1), 44–48. https://doi.org/10.1016/S0030-4018(99)00112-1