Spectroscopic investigations of femtosecond laser irradiated polystyrene and fabrication of microstructures

We report microfabrication of structures in bulk and thin films of polystyrene (PS) using femtosecond (fs) laser pulses. For the first time to our knowledge, we report emission from the fs laser modified regions of bulk and thin films of PS when excited at 458, 488, and 514 nm. Moreover, we report the existence of peroxide type free radicals, for the first time, in fs laser irradiated bulk PS. We observed the suppression of Raman modes in case of structures fabricated at higher energies and the same effect was noticed in central portion of the structures fabricated. No appreciable broadening was observed in the case of structures fabricated at low energies. Possible applications resulting from such structures are discussed briefly.

Research highlights
► Femtosecond microfabrication in the bulk/thin films of polystyrene is reported.
► Emission due to formation of optical centers from fs laser modified regions is reported.
► Existence of peroxide type free radicals in the fs laser irradiated regions is confirmed.
► Micro-Raman studies were performed to understand the changes in fs modified regions.