Figure 2: Scheme of the typical for DLSS experiment signals: short modulating laser light pulse (1), long probe light pulse (2), and resulting induced absorption signal (3) after crystal transfer. Insets (3a)–(3c) show detailed signals of different nature: coherent inertialess two-photon absorption (3a), combinations of TPA, and laser modulation of incoherent two-step absorption (induced absorption (3b) and bleaching (3c)).