Theory 01/Ultrafast/Laser imaging
Damage Is Pulse Against Diffusion
The claim
Photodamage in ultrafast imaging is set by the ratio of pulse duration to thermal diffusion time, not by deposited energy, so the same energy can be safe or destructive depending on pulse length.
01Mechanism
A short pulse deposits energy before heat can spread, which can exceed a local damage threshold; a long pulse of equal energy lets diffusion disperse it.
02Prediction
Damage should track the ratio across pulse lengths.
03Refutation
Damage tracking energy alone would remove the diffusion term.