Steady-state mechanism for polymer ablation by a free-running Er:YAG laser
Applied Surface Science, 253(5), 2386- 2392, December 2006
Stephen P. Kelty, Ph.D.
Department of Chemistry and Biochemistry
D. M. Bubb, A. O. Sezerm, D. Harris & F. Rezae
A free-running Er:YAG laser is used to ablate polyethylene glycol and the ablation yield is studied as a function of molecular weight (1000–10,000 g/mol) and laser fluence (8–25 J/cm2). A steady-state ablation mechanism is proposed which includes recoil-induced expulsion as the primary contributor to the ablation yield. It is also proposed that the formation of a molten layer is a necessary part of the ablation mechanism because the calculated tensile strengths for the solid polymer are too large to permit fracture of the target due to the laser-induced stress transient.