Multiplex picosecond time-resolved coherent anti-Stokes Raman spectroscopy (CARS) is used to study the dynamics of a thin film of a polymer, poly-methyl methacrylate (PMMA), undergoing photothermal laser ablation. Time-dependent CARS spectra of a PMMA Raman transition near 810 cm−1 reveal line broadening, attributed to temperature increase, peak shift, attributed to rapid volume expansion, and the appearance of a new peak attributed to the formation of methyl methacrylate by picosecond time scale polymer thermal decomposition. This is believed to be the first direct observation of a chemical reaction product in the solid itself, during laser ablation.
No takes yet. Share an insight, caveat, or question.
Hare et al. (1994) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: