Raman spectroscopic characterization of crater walls formed upon single-shot high-energy femtosecond laser irradiation of dimethacrylate polymer doped with plasmonic gold nanorods.

The bonding configuration of the crater walls formed in urethane dimethacrylate-based polymer doped with plasmonic gold nanorods upon irradiation with a single-shot high-energy femtosecond laser pulse has been studied by Raman spectroscopy. New Raman bands were detected in the 2000-2500 cm region of the Raman spectrum the intensities of which showed strong dependence on the concentration of the plasmonic nanoparticles and the energy of the laser pulse. Based on model calculations of the Raman frequencies of the polymer these peaks were attributed to carbon-deuterium and nitrogen-deuterium vibrations. Their appearance might indicate the occurrence of nuclear reactions in the polymer excited by the ultra-strong laser field amplified by the plasmonic nanoparticles.