Figure 6: Calculated kinetics of -DLSS signals in the spectral area of impurity bleaching ( ) for different levels of modulation ; for the cases: without (a) and with account (b) of the coherent TPA contribution. (a) (12) for a Gaussian laser pulse (19) with  ns (dotted line, integrated envelope ). Inset-corresponding LID with the numbered points for which the shown same numbered kinetics were calculated (  MW/cm2). Parameters:  cm−3, = = = 10−17 cm2, = 10−5 s, = 1021 s−1. (b) Similar calculations, but with adding the contribution of an opposite TPA signal ( = 0,01 cm/MW).