Optical emission spectroscopic studies of ultrashort laser produced graphene oxide plasma

Optical emission spectroscopy (OES) is a reasonably accurate and non-intrusive technique for measuring various plasma parameters. Herein, we report the expansion dynamics of ionic species present in the graphene oxide (GO) plasma generated by an ultrafast laser (120fs, 800nm, 10Hz). Natural graphite powder was used to synthesize graphene oxide (GO) using the modified Hummers' method. The expansion dynamics of the GO plasma was characterised using space resolved optical emission spectroscopy. Plasma parameters like electron temperature (T_e) was measured by Boltzmann plot method and the electron number density (n_e) was estimated using stark broadened profiles of isolated lines of the optical emission spectra. These studies have potential applications in multiple areas like ion acceleration, pulsed laser deposition, laser driven plasma accelerators, LIBS etc. (author)