Theory 03/Ultrafast/Laser ablation
Ablation Needs Coupling Time
The claim
The ablation threshold in metals is set by the ratio of pulse length to electron-phonon coupling time, so shorter pulses ablate at lower fluence.
01Mechanism
Energy must transfer from electrons to the lattice before material is removed; pulses shorter than the coupling time concentrate energy in electrons and ablate efficiently.
02Prediction
Threshold should fall as the ratio falls.
03Refutation
Threshold tracking fluence alone would remove the coupling.