It is well known that the multiphoton absorption is highly sensitive to the intensity.
Caption: FIGURE 4: The change of multiphoton absorption region in the microrod with pump power increase: (a) low power; (b) higher power; (c) high power.
In CARS microscopy employing near-infrared pulse lasers, the photo-induced damage is dominantly caused by multiphoton induced phenomena, such as multiphoton absorption
, oxidation stress, and free-radical generation [11-14].
Merkle and Kitriotis  reported that both single and multiple pulse (16 ns at 1064 nm, 10 ns at 532 nm) damage differed very little between 80 K and 295 K, and they compared the temperature dependence with several damage mechanisms, including multiphoton absorption
, electron avalanche, inclusion heating, and bond breaking.
In this material, recording is done by changing the isomer distribution through multiphoton absorption